From 24a25fd79c515050574d94818f7a1d5e65be55b5 Mon Sep 17 00:00:00 2001
From: Anders Hejlsberg <andersh@microsoft.com>
Date: Mon, 22 May 2017 08:46:47 -0700
Subject: [PATCH 01/56] Revise type inference data structures

---
 src/compiler/checker.ts | 145 +++++++++++++++++++++-------------------
 src/compiler/types.ts   |  26 ++++---
 2 files changed, 90 insertions(+), 81 deletions(-)

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 70403146489..1bba954971a 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -7921,10 +7921,10 @@ namespace ts {
         function getInferenceMapper(context: InferenceContext): TypeMapper {
             if (!context.mapper) {
                 const mapper: TypeMapper = t => {
-                    const typeParameters = context.signature.typeParameters;
-                    for (let i = 0; i < typeParameters.length; i++) {
-                        if (t === typeParameters[i]) {
-                            context.inferences[i].isFixed = true;
+                    const inferences = context.inferences;
+                    for (let i = 0; i < inferences.length; i++) {
+                        if (t === inferences[i].typeParameter) {
+                            inferences[i].isFixed = true;
                             return getInferredType(context, i);
                         }
                     }
@@ -10131,22 +10131,22 @@ namespace ts {
         }
 
         function createInferenceContext(signature: Signature, inferUnionTypes: boolean, useAnyForNoInferences: boolean): InferenceContext {
-            const inferences = map(signature.typeParameters, createTypeInferencesObject);
             return {
                 signature,
+                inferences: map(signature.typeParameters, createInferenceInfo),
                 inferUnionTypes,
-                inferences,
-                inferredTypes: new Array(signature.typeParameters.length),
                 useAnyForNoInferences
             };
         }
 
-        function createTypeInferencesObject(): TypeInferences {
+        function createInferenceInfo(typeParameter: TypeParameter): InferenceInfo {
             return {
-                primary: undefined,
-                secondary: undefined,
+                typeParameter,
+                candidates: undefined,
+                inferredType: undefined,
+                priority: undefined,
                 topLevel: true,
-                isFixed: false,
+                isFixed: false
             };
         }
 
@@ -10183,10 +10183,9 @@ namespace ts {
             if (properties.length === 0 && !indexInfo) {
                 return undefined;
             }
-            const typeVariable = <TypeVariable>getIndexedAccessType((<IndexType>getConstraintTypeFromMappedType(target)).type, getTypeParameterFromMappedType(target));
-            const typeVariableArray = [typeVariable];
-            const typeInferences = createTypeInferencesObject();
-            const typeInferencesArray = [typeInferences];
+            const typeParameter = <TypeParameter>getIndexedAccessType((<IndexType>getConstraintTypeFromMappedType(target)).type, getTypeParameterFromMappedType(target));
+            const inference = createInferenceInfo(typeParameter);
+            const inferences = [inference];
             const templateType = getTemplateTypeFromMappedType(target);
             const readonlyMask = target.declaration.readonlyToken ? false : true;
             const optionalMask = target.declaration.questionToken ? 0 : SymbolFlags.Optional;
@@ -10212,22 +10211,20 @@ namespace ts {
             return createAnonymousType(undefined, members, emptyArray, emptyArray, indexInfo, undefined);
 
             function inferTargetType(sourceType: Type): Type {
-                typeInferences.primary = undefined;
-                typeInferences.secondary = undefined;
-                inferTypes(typeVariableArray, typeInferencesArray, sourceType, templateType);
-                const inferences = typeInferences.primary || typeInferences.secondary;
-                return inferences && getUnionType(inferences, /*subtypeReduction*/ true);
+                inference.candidates = undefined;
+                inferTypes(inferences, sourceType, templateType);
+                return inference.candidates && getUnionType(inference.candidates, /*subtypeReduction*/ true);
             }
         }
 
         function inferTypesWithContext(context: InferenceContext, originalSource: Type, originalTarget: Type) {
-            inferTypes(context.signature.typeParameters, context.inferences, originalSource, originalTarget);
+            inferTypes(context.inferences, originalSource, originalTarget);
         }
 
-        function inferTypes(typeVariables: TypeVariable[], typeInferences: TypeInferences[], originalSource: Type, originalTarget: Type) {
+        function inferTypes(inferences: InferenceInfo[], originalSource: Type, originalTarget: Type) {
             let symbolStack: Symbol[];
             let visited: Map<boolean>;
-            let inferiority = 0;
+            let priority = 0;
             inferFromTypes(originalSource, originalTarget);
 
             function inferFromTypes(source: Type, target: Type) {
@@ -10291,24 +10288,24 @@ namespace ts {
                     if (source.flags & TypeFlags.ContainsAnyFunctionType) {
                         return;
                     }
-                    for (let i = 0; i < typeVariables.length; i++) {
-                        if (target === typeVariables[i]) {
-                            const inferences = typeInferences[i];
-                            if (!inferences.isFixed) {
+                    for (const inference of inferences) {
+                        if (target === inference.typeParameter) {
+                            if (!inference.isFixed) {
                                 // Any inferences that are made to a type parameter in a union type are inferior
                                 // to inferences made to a flat (non-union) type. This is because if we infer to
                                 // T | string[], we really don't know if we should be inferring to T or not (because
                                 // the correct constituent on the target side could be string[]). Therefore, we put
                                 // such inferior inferences into a secondary bucket, and only use them if the primary
                                 // bucket is empty.
-                                const candidates = inferiority ?
-                                    inferences.secondary || (inferences.secondary = []) :
-                                    inferences.primary || (inferences.primary = []);
-                                if (!contains(candidates, source)) {
-                                    candidates.push(source);
+                                if (!inference.candidates || priority < inference.priority) {
+                                    inference.candidates = [source];
+                                    inference.priority = priority;
+                                }
+                                else if (priority === inference.priority) {
+                                    inference.candidates.push(source);
                                 }
                                 if (target.flags & TypeFlags.TypeParameter && !isTypeParameterAtTopLevel(originalTarget, <TypeParameter>target)) {
-                                    inferences.topLevel = false;
+                                    inference.topLevel = false;
                                 }
                             }
                             return;
@@ -10330,7 +10327,7 @@ namespace ts {
                     let typeVariable: TypeVariable;
                     // First infer to each type in union or intersection that isn't a type variable
                     for (const t of targetTypes) {
-                        if (t.flags & TypeFlags.TypeVariable && contains(typeVariables, t)) {
+                        if (getInferenceInfoForType(t)) {
                             typeVariable = <TypeVariable>t;
                             typeVariableCount++;
                         }
@@ -10342,9 +10339,10 @@ namespace ts {
                     // variable. This gives meaningful results for union types in co-variant positions and intersection
                     // types in contra-variant positions (such as callback parameters).
                     if (typeVariableCount === 1) {
-                        inferiority++;
+                        const savePriority = priority;
+                        priority |= InferencePriority.NakedTypeVariable;
                         inferFromTypes(source, typeVariable);
-                        inferiority--;
+                        priority = savePriority;
                     }
                 }
                 else if (source.flags & TypeFlags.UnionOrIntersection) {
@@ -10384,6 +10382,17 @@ namespace ts {
                 }
             }
 
+            function getInferenceInfoForType(type: Type) {
+                if (type.flags & TypeFlags.TypeVariable) {
+                    for (const inference of inferences) {
+                        if (type === inference.typeParameter) {
+                            return inference;
+                        }
+                    }
+                }
+                return undefined;
+            }
+
             function inferFromObjectTypes(source: Type, target: Type) {
                 if (getObjectFlags(target) & ObjectFlags.Mapped) {
                     const constraintType = getConstraintTypeFromMappedType(<MappedType>target);
@@ -10392,13 +10401,14 @@ namespace ts {
                         // where T is a type variable. Use inferTypeForHomomorphicMappedType to infer a suitable source
                         // type and then make a secondary inference from that type to T. We make a secondary inference
                         // such that direct inferences to T get priority over inferences to Partial<T>, for example.
-                        const index = indexOf(typeVariables, (<IndexType>constraintType).type);
-                        if (index >= 0 && !typeInferences[index].isFixed) {
+                        const inference = getInferenceInfoForType((<IndexType>constraintType).type);
+                        if (inference && !inference.isFixed) {
                             const inferredType = inferTypeForHomomorphicMappedType(source, <MappedType>target);
                             if (inferredType) {
-                                inferiority++;
-                                inferFromTypes(inferredType, typeVariables[index]);
-                                inferiority--;
+                                const savePriority = priority;
+                                priority |= InferencePriority.MappedType;
+                                inferFromTypes(inferredType, inference.typeParameter);
+                                priority = savePriority;
                             }
                         }
                         return;
@@ -10497,33 +10507,29 @@ namespace ts {
             return type.flags & TypeFlags.Union ? getUnionType(reducedTypes) : getIntersectionType(reducedTypes);
         }
 
-        function getInferenceCandidates(context: InferenceContext, index: number): Type[] {
-            const inferences = context.inferences[index];
-            return inferences.primary || inferences.secondary || emptyArray;
-        }
-
         function hasPrimitiveConstraint(type: TypeParameter): boolean {
             const constraint = getConstraintOfTypeParameter(type);
             return constraint && maybeTypeOfKind(constraint, TypeFlags.Primitive | TypeFlags.Index);
         }
 
         function getInferredType(context: InferenceContext, index: number): Type {
-            let inferredType = context.inferredTypes[index];
+            const inference = context.inferences[index];
+            let inferredType = inference.inferredType;
             let inferenceSucceeded: boolean;
             if (!inferredType) {
-                const inferences = getInferenceCandidates(context, index);
-                if (inferences.length) {
+                const candidates = inference.candidates;
+                if (candidates) {
                     // We widen inferred literal types if
                     // all inferences were made to top-level ocurrences of the type parameter, and
                     // the type parameter has no constraint or its constraint includes no primitive or literal types, and
                     // the type parameter was fixed during inference or does not occur at top-level in the return type.
                     const signature = context.signature;
-                    const widenLiteralTypes = context.inferences[index].topLevel &&
-                        !hasPrimitiveConstraint(signature.typeParameters[index]) &&
-                        (context.inferences[index].isFixed || !isTypeParameterAtTopLevel(getReturnTypeOfSignature(signature), signature.typeParameters[index]));
-                    const baseInferences = widenLiteralTypes ? sameMap(inferences, getWidenedLiteralType) : inferences;
+                    const widenLiteralTypes = inference.topLevel &&
+                        !hasPrimitiveConstraint(inference.typeParameter) &&
+                        (inference.isFixed || !isTypeParameterAtTopLevel(getReturnTypeOfSignature(signature), inference.typeParameter));
+                    const baseCandidates = widenLiteralTypes ? sameMap(candidates, getWidenedLiteralType) : candidates;
                     // Infer widened union or supertype, or the unknown type for no common supertype
-                    const unionOrSuperType = context.inferUnionTypes ? getUnionType(baseInferences, /*subtypeReduction*/ true) : getCommonSupertype(baseInferences);
+                    const unionOrSuperType = context.inferUnionTypes ? getUnionType(baseCandidates, /*subtypeReduction*/ true) : getCommonSupertype(baseCandidates);
                     inferredType = unionOrSuperType ? getWidenedType(unionOrSuperType) : unknownType;
                     inferenceSucceeded = !!unionOrSuperType;
                 }
@@ -10533,7 +10539,7 @@ namespace ts {
                     // succeeds, meaning there is no error for not having inference candidates. An
                     // inference error only occurs when there are *conflicting* candidates, i.e.
                     // candidates with no common supertype.
-                    const defaultType = getDefaultFromTypeParameter(context.signature.typeParameters[index]);
+                    const defaultType = getDefaultFromTypeParameter(inference.typeParameter);
                     if (defaultType) {
                         // Instantiate the default type. Any forward reference to a type
                         // parameter should be instantiated to the empty object type.
@@ -10548,7 +10554,7 @@ namespace ts {
 
                     inferenceSucceeded = true;
                 }
-                context.inferredTypes[index] = inferredType;
+                inference.inferredType = inferredType;
 
                 // Only do the constraint check if inference succeeded (to prevent cascading errors)
                 if (inferenceSucceeded) {
@@ -10556,7 +10562,7 @@ namespace ts {
                     if (constraint) {
                         const instantiatedConstraint = instantiateType(constraint, getInferenceMapper(context));
                         if (!isTypeAssignableTo(inferredType, getTypeWithThisArgument(instantiatedConstraint, inferredType))) {
-                            context.inferredTypes[index] = inferredType = instantiatedConstraint;
+                            inference.inferredType = inferredType = instantiatedConstraint;
                         }
                     }
                 }
@@ -10571,10 +10577,11 @@ namespace ts {
         }
 
         function getInferredTypes(context: InferenceContext): Type[] {
-            for (let i = 0; i < context.inferredTypes.length; i++) {
-                getInferredType(context, i);
+            let result = [];
+            for (let i = 0; i < context.inferences.length; i++) {
+                result.push(getInferredType(context, i));
             }
-            return context.inferredTypes;
+            return result;
         }
 
         // EXPRESSION TYPE CHECKING
@@ -14837,18 +14844,18 @@ namespace ts {
             return getSignatureInstantiation(signature, getInferredTypes(context));
         }
 
-        function inferTypeArguments(node: CallLikeExpression, signature: Signature, args: Expression[], excludeArgument: boolean[], context: InferenceContext): void {
-            const typeParameters = signature.typeParameters;
+        function inferTypeArguments(node: CallLikeExpression, signature: Signature, args: Expression[], excludeArgument: boolean[], context: InferenceContext): Type[] {
+            const inferences = context.inferences;
             const inferenceMapper = getInferenceMapper(context);
 
             // Clear out all the inference results from the last time inferTypeArguments was called on this context
-            for (let i = 0; i < typeParameters.length; i++) {
+            for (let i = 0; i < inferences.length; i++) {
                 // As an optimization, we don't have to clear (and later recompute) inferred types
                 // for type parameters that have already been fixed on the previous call to inferTypeArguments.
                 // It would be just as correct to reset all of them. But then we'd be repeating the same work
                 // for the type parameters that were fixed, namely the work done by getInferredType.
-                if (!context.inferences[i].isFixed) {
-                    context.inferredTypes[i] = undefined;
+                if (!inferences[i].isFixed) {
+                    inferences[i].inferredType = undefined;
                 }
             }
 
@@ -14908,8 +14915,7 @@ namespace ts {
                     }
                 }
             }
-
-            getInferredTypes(context);
+            return getInferredTypes(context);
         }
 
         function checkTypeArguments(signature: Signature, typeArgumentNodes: TypeNode[], typeArgumentTypes: Type[], reportErrors: boolean, headMessage?: DiagnosticMessage): boolean {
@@ -15491,7 +15497,7 @@ namespace ts {
                 else {
                     Debug.assert(resultOfFailedInference.failedTypeParameterIndex >= 0);
                     const failedTypeParameter = candidateForTypeArgumentError.typeParameters[resultOfFailedInference.failedTypeParameterIndex];
-                    const inferenceCandidates = getInferenceCandidates(resultOfFailedInference, resultOfFailedInference.failedTypeParameterIndex);
+                    const inferenceCandidates = resultOfFailedInference.inferences[resultOfFailedInference.failedTypeParameterIndex].candidates;
 
                     let diagnosticChainHead = chainDiagnosticMessages(/*details*/ undefined, // details will be provided by call to reportNoCommonSupertypeError
                         Diagnostics.The_type_argument_for_type_parameter_0_cannot_be_inferred_from_the_usage_Consider_specifying_the_type_arguments_explicitly,
@@ -15576,8 +15582,7 @@ namespace ts {
                                 typeArgumentsAreValid = checkTypeArguments(candidate, typeArguments, typeArgumentTypes, /*reportErrors*/ false);
                             }
                             else {
-                                inferTypeArguments(node, candidate, args, excludeArgument, inferenceContext);
-                                typeArgumentTypes = inferenceContext.inferredTypes;
+                                typeArgumentTypes = inferTypeArguments(node, candidate, args, excludeArgument, inferenceContext);
                                 typeArgumentsAreValid = inferenceContext.failedTypeParameterIndex === undefined;
                             }
                             if (!typeArgumentsAreValid) {
diff --git a/src/compiler/types.ts b/src/compiler/types.ts
index 4b95c957f74..34aada91f7c 100644
--- a/src/compiler/types.ts
+++ b/src/compiler/types.ts
@@ -3341,25 +3341,29 @@ namespace ts {
                                     // The identity mapper and regular instantiation mappers do not need it.
     }
 
-    /* @internal */
-    export interface TypeInferences {
-        primary: Type[];    // Inferences made directly to a type parameter
-        secondary: Type[];  // Inferences made to a type parameter in a union type
-        topLevel: boolean;  // True if all inferences were made from top-level (not nested in object type) locations
-        isFixed: boolean;   // Whether the type parameter is fixed, as defined in section 4.12.2 of the TypeScript spec
-                            // If a type parameter is fixed, no more inferences can be made for the type parameter
+    export const enum InferencePriority {
+        NakedTypeVariable = 1 << 0,  // Naked type variable in union or intersection type
+        MappedType        = 1 << 1,  // Reverse inference for mapped type
+    }
+
+    export interface InferenceInfo {
+        typeParameter: TypeParameter;
+        candidates: Type[];
+        inferredType: Type;
+        priority: InferencePriority;
+        topLevel: boolean;
+        isFixed: boolean;
     }
 
     /* @internal */
     export interface InferenceContext {
         signature: Signature;               // Generic signature for which inferences are made
-        inferUnionTypes: boolean;           // Infer union types for disjoint candidates (otherwise undefinedType)
-        inferences: TypeInferences[];       // Inferences made for each type parameter
-        inferredTypes: Type[];              // Inferred type for each type parameter
+        inferences: InferenceInfo[];        // Inferences made for each type parameter
         mapper?: TypeMapper;                // Type mapper for this inference context
+        inferUnionTypes: boolean;           // Infer union types for disjoint candidates (otherwise undefinedType)
+        useAnyForNoInferences: boolean;     // Use any instead of {} for no inferences
         failedTypeParameterIndex?: number;  // Index of type parameter for which inference failed
         // It is optional because in contextual signature instantiation, nothing fails
-        useAnyForNoInferences?: boolean;    // Use any instead of {} for no inferences
     }
 
     /* @internal */

From e19d934b7300125807ab5d4df1b8aff215803476 Mon Sep 17 00:00:00 2001
From: Anders Hejlsberg <andersh@microsoft.com>
Date: Mon, 22 May 2017 11:59:25 -0700
Subject: [PATCH 02/56] Initial implementation of return type inference

---
 src/compiler/checker.ts | 60 ++++++++++++++++++++++++++++++++---------
 src/compiler/types.ts   |  4 ++-
 2 files changed, 51 insertions(+), 13 deletions(-)

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 1bba954971a..5bd708a2fbc 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -7937,6 +7937,10 @@ namespace ts {
             return context.mapper;
         }
 
+        function cloneTypeMapper(mapper: TypeMapper): TypeMapper {
+            return mapper && mapper.context ? getInferenceMapper(cloneInferenceContext(mapper.context)) : mapper;
+        }
+
         function identityMapper(type: Type): Type {
             return type;
         }
@@ -10130,12 +10134,13 @@ namespace ts {
             }
         }
 
-        function createInferenceContext(signature: Signature, inferUnionTypes: boolean, useAnyForNoInferences: boolean): InferenceContext {
+        function createInferenceContext(callNode: CallLikeExpression, signature: Signature, inferUnionTypes: boolean, noInferenceType: Type): InferenceContext {
             return {
+                callNode,
                 signature,
                 inferences: map(signature.typeParameters, createInferenceInfo),
                 inferUnionTypes,
-                useAnyForNoInferences
+                noInferenceType
             };
         }
 
@@ -10150,6 +10155,27 @@ namespace ts {
             };
         }
 
+        function cloneInferenceContext(context: InferenceContext): InferenceContext {
+            return {
+                callNode: context.callNode,
+                signature: context.signature,
+                inferences: map(context.inferences, cloneInferenceInfo),
+                inferUnionTypes: context.inferUnionTypes,
+                noInferenceType: silentNeverType
+            }
+        }
+
+        function cloneInferenceInfo(inference: InferenceInfo): InferenceInfo {
+            return {
+                typeParameter: inference.typeParameter,
+                candidates: inference.candidates && inference.candidates.slice(),
+                inferredType: inference.inferredType,
+                priority: inference.priority,
+                topLevel: inference.topLevel,
+                isFixed: inference.isFixed
+            };
+        }
+
         // Return true if the given type could possibly reference a type parameter for which
         // we perform type inference (i.e. a type parameter of a generic function). We cache
         // results for union and intersection types for performance reasons.
@@ -10221,10 +10247,9 @@ namespace ts {
             inferTypes(context.inferences, originalSource, originalTarget);
         }
 
-        function inferTypes(inferences: InferenceInfo[], originalSource: Type, originalTarget: Type) {
+        function inferTypes(inferences: InferenceInfo[], originalSource: Type, originalTarget: Type, priority: InferencePriority = 0) {
             let symbolStack: Symbol[];
             let visited: Map<boolean>;
-            let priority = 0;
             inferFromTypes(originalSource, originalTarget);
 
             function inferFromTypes(source: Type, target: Type) {
@@ -10285,7 +10310,7 @@ namespace ts {
                     // it as an inference candidate. Hopefully, a better candidate will come along that does
                     // not contain anyFunctionType when we come back to this argument for its second round
                     // of inference.
-                    if (source.flags & TypeFlags.ContainsAnyFunctionType) {
+                    if (source.flags & TypeFlags.ContainsAnyFunctionType || source === silentNeverType) {
                         return;
                     }
                     for (const inference of inferences) {
@@ -10517,8 +10542,19 @@ namespace ts {
             let inferredType = inference.inferredType;
             let inferenceSucceeded: boolean;
             if (!inferredType) {
-                const candidates = inference.candidates;
-                if (candidates) {
+                if (!inference.candidates && context.callNode && isExpression(context.callNode)) {
+                    const contextualType = getContextualType(context.callNode);
+                    if (contextualType) {
+                        const mapper = cloneTypeMapper(getContextualMapper(context.callNode));
+                        const instantiatedType = instantiateType(contextualType, mapper);
+                        const returnType = getReturnTypeOfSignature(context.signature);
+                        const saveFixed = inference.isFixed;
+                        inference.isFixed = false;
+                        inferTypes([inference], instantiatedType, returnType, InferencePriority.ReturnType);
+                        inference.isFixed = saveFixed;
+                    }
+                }
+                if (inference.candidates) {
                     // We widen inferred literal types if
                     // all inferences were made to top-level ocurrences of the type parameter, and
                     // the type parameter has no constraint or its constraint includes no primitive or literal types, and
@@ -10527,7 +10563,7 @@ namespace ts {
                     const widenLiteralTypes = inference.topLevel &&
                         !hasPrimitiveConstraint(inference.typeParameter) &&
                         (inference.isFixed || !isTypeParameterAtTopLevel(getReturnTypeOfSignature(signature), inference.typeParameter));
-                    const baseCandidates = widenLiteralTypes ? sameMap(candidates, getWidenedLiteralType) : candidates;
+                    const baseCandidates = widenLiteralTypes ? sameMap(inference.candidates, getWidenedLiteralType) : inference.candidates;
                     // Infer widened union or supertype, or the unknown type for no common supertype
                     const unionOrSuperType = context.inferUnionTypes ? getUnionType(baseCandidates, /*subtypeReduction*/ true) : getCommonSupertype(baseCandidates);
                     inferredType = unionOrSuperType ? getWidenedType(unionOrSuperType) : unknownType;
@@ -10539,7 +10575,7 @@ namespace ts {
                     // succeeds, meaning there is no error for not having inference candidates. An
                     // inference error only occurs when there are *conflicting* candidates, i.e.
                     // candidates with no common supertype.
-                    const defaultType = getDefaultFromTypeParameter(inference.typeParameter);
+                    const defaultType = context.noInferenceType === silentNeverType ? undefined : getDefaultFromTypeParameter(inference.typeParameter);
                     if (defaultType) {
                         // Instantiate the default type. Any forward reference to a type
                         // parameter should be instantiated to the empty object type.
@@ -10549,7 +10585,7 @@ namespace ts {
                                 getInferenceMapper(context)));
                     }
                     else {
-                        inferredType = context.useAnyForNoInferences ? anyType : emptyObjectType;
+                        inferredType = context.noInferenceType;
                     }
 
                     inferenceSucceeded = true;
@@ -14836,7 +14872,7 @@ namespace ts {
 
         // Instantiate a generic signature in the context of a non-generic signature (section 3.8.5 in TypeScript spec)
         function instantiateSignatureInContextOf(signature: Signature, contextualSignature: Signature, contextualMapper: TypeMapper): Signature {
-            const context = createInferenceContext(signature, /*inferUnionTypes*/ true, /*useAnyForNoInferences*/ false);
+            const context = createInferenceContext(/*callNode*/ undefined, signature, /*inferUnionTypes*/ true, /*noInferenceType*/ emptyObjectType);
             forEachMatchingParameterType(contextualSignature, signature, (source, target) => {
                 // Type parameters from outer context referenced by source type are fixed by instantiation of the source type
                 inferTypesWithContext(context, instantiateType(source, contextualMapper), target);
@@ -15570,7 +15606,7 @@ namespace ts {
                     let candidate: Signature;
                     let typeArgumentsAreValid: boolean;
                     const inferenceContext = originalCandidate.typeParameters
-                        ? createInferenceContext(originalCandidate, /*inferUnionTypes*/ false, /*useAnyForNoInferences*/ isInJavaScriptFile(node))
+                        ? createInferenceContext(node, originalCandidate, /*inferUnionTypes*/ false, /*noInferenceType*/ isInJavaScriptFile(node) ? anyType : emptyObjectType)
                         : undefined;
 
                     while (true) {
diff --git a/src/compiler/types.ts b/src/compiler/types.ts
index 34aada91f7c..5e5c2851bf8 100644
--- a/src/compiler/types.ts
+++ b/src/compiler/types.ts
@@ -3344,6 +3344,7 @@ namespace ts {
     export const enum InferencePriority {
         NakedTypeVariable = 1 << 0,  // Naked type variable in union or intersection type
         MappedType        = 1 << 1,  // Reverse inference for mapped type
+        ReturnType        = 1 << 2,  // Inference made from return type of generic function
     }
 
     export interface InferenceInfo {
@@ -3357,11 +3358,12 @@ namespace ts {
 
     /* @internal */
     export interface InferenceContext {
+        callNode: CallLikeExpression;       // Call expression node for which inferences are made
         signature: Signature;               // Generic signature for which inferences are made
         inferences: InferenceInfo[];        // Inferences made for each type parameter
         mapper?: TypeMapper;                // Type mapper for this inference context
         inferUnionTypes: boolean;           // Infer union types for disjoint candidates (otherwise undefinedType)
-        useAnyForNoInferences: boolean;     // Use any instead of {} for no inferences
+        noInferenceType: Type;              // Type to use for no inferences
         failedTypeParameterIndex?: number;  // Index of type parameter for which inference failed
         // It is optional because in contextual signature instantiation, nothing fails
     }

From 68056d52c43e8a04c68980049a60aaa9e92329da Mon Sep 17 00:00:00 2001
From: Anders Hejlsberg <andersh@microsoft.com>
Date: Mon, 22 May 2017 14:55:27 -0700
Subject: [PATCH 03/56] Clean up implementation

---
 src/compiler/checker.ts | 92 +++++++++++++++++++++--------------------
 src/compiler/types.ts   |  9 +++-
 2 files changed, 55 insertions(+), 46 deletions(-)

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 5bd708a2fbc..222eb4601d9 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -10134,13 +10134,12 @@ namespace ts {
             }
         }
 
-        function createInferenceContext(callNode: CallLikeExpression, signature: Signature, inferUnionTypes: boolean, noInferenceType: Type): InferenceContext {
+        function createInferenceContext(callNode: CallLikeExpression, signature: Signature, flags: InferenceFlags): InferenceContext {
             return {
                 callNode,
                 signature,
                 inferences: map(signature.typeParameters, createInferenceInfo),
-                inferUnionTypes,
-                noInferenceType
+                flags,
             };
         }
 
@@ -10160,8 +10159,7 @@ namespace ts {
                 callNode: context.callNode,
                 signature: context.signature,
                 inferences: map(context.inferences, cloneInferenceInfo),
-                inferUnionTypes: context.inferUnionTypes,
-                noInferenceType: silentNeverType
+                flags: context.flags | InferenceFlags.NoDefault,
             }
         }
 
@@ -10243,10 +10241,6 @@ namespace ts {
             }
         }
 
-        function inferTypesWithContext(context: InferenceContext, originalSource: Type, originalTarget: Type) {
-            inferTypes(context.inferences, originalSource, originalTarget);
-        }
-
         function inferTypes(inferences: InferenceInfo[], originalSource: Type, originalTarget: Type, priority: InferencePriority = 0) {
             let symbolStack: Symbol[];
             let visited: Map<boolean>;
@@ -10315,13 +10309,10 @@ namespace ts {
                     }
                     for (const inference of inferences) {
                         if (target === inference.typeParameter) {
-                            if (!inference.isFixed) {
-                                // Any inferences that are made to a type parameter in a union type are inferior
-                                // to inferences made to a flat (non-union) type. This is because if we infer to
-                                // T | string[], we really don't know if we should be inferring to T or not (because
-                                // the correct constituent on the target side could be string[]). Therefore, we put
-                                // such inferior inferences into a secondary bucket, and only use them if the primary
-                                // bucket is empty.
+                            // Even if an inference is marked as fixed, we can add candidates from inferences made
+                            // from the return type of generic functions (which only happens when no other candidates
+                            // are present).
+                            if (!inference.isFixed || priority & InferencePriority.ReturnType) {
                                 if (!inference.candidates || priority < inference.priority) {
                                     inference.candidates = [source];
                                     inference.priority = priority;
@@ -10543,15 +10534,21 @@ namespace ts {
             let inferenceSucceeded: boolean;
             if (!inferredType) {
                 if (!inference.candidates && context.callNode && isExpression(context.callNode)) {
+                    // We have no inference candidates. Now attempt to get the contextual type for the call
+                    // expression associated with the context, and if a contextual type is available, infer
+                    // from that type to the return type of the call expression. For example, given a
+                    // 'function wrap<T, U>(cb: (x: T) => U): (x: T) => U' and a call expression
+                    // 'let f: (x: string) => number = wrap(s => s.length)', we infer from the declared type
+                    // of 'f' to the return type of 'wrap'.
                     const contextualType = getContextualType(context.callNode);
                     if (contextualType) {
+                        // We clone the contextual mapper to avoid disturbing a resolution in progress for an
+                        // outer call expression. Effectively we just want a snapshot of whatever has been
+                        // inferred for any outer call expression so far.
                         const mapper = cloneTypeMapper(getContextualMapper(context.callNode));
                         const instantiatedType = instantiateType(contextualType, mapper);
                         const returnType = getReturnTypeOfSignature(context.signature);
-                        const saveFixed = inference.isFixed;
-                        inference.isFixed = false;
                         inferTypes([inference], instantiatedType, returnType, InferencePriority.ReturnType);
-                        inference.isFixed = saveFixed;
                     }
                 }
                 if (inference.candidates) {
@@ -10564,30 +10561,37 @@ namespace ts {
                         !hasPrimitiveConstraint(inference.typeParameter) &&
                         (inference.isFixed || !isTypeParameterAtTopLevel(getReturnTypeOfSignature(signature), inference.typeParameter));
                     const baseCandidates = widenLiteralTypes ? sameMap(inference.candidates, getWidenedLiteralType) : inference.candidates;
-                    // Infer widened union or supertype, or the unknown type for no common supertype
-                    const unionOrSuperType = context.inferUnionTypes ? getUnionType(baseCandidates, /*subtypeReduction*/ true) : getCommonSupertype(baseCandidates);
+                    // Infer widened union or supertype, or the unknown type for no common supertype. We infer union types
+                    // for inferences coming from return types in order to avoid common supertype failures.
+                    const unionOrSuperType = context.flags & InferenceFlags.InferUnionTypes || inference.priority & InferencePriority.ReturnType ?
+                        getUnionType(baseCandidates, /*subtypeReduction*/ true) : getCommonSupertype(baseCandidates);
                     inferredType = unionOrSuperType ? getWidenedType(unionOrSuperType) : unknownType;
                     inferenceSucceeded = !!unionOrSuperType;
                 }
                 else {
-                    // Infer either the default or the empty object type when no inferences were
-                    // made. It is important to remember that in this case, inference still
-                    // succeeds, meaning there is no error for not having inference candidates. An
-                    // inference error only occurs when there are *conflicting* candidates, i.e.
-                    // candidates with no common supertype.
-                    const defaultType = context.noInferenceType === silentNeverType ? undefined : getDefaultFromTypeParameter(inference.typeParameter);
-                    if (defaultType) {
-                        // Instantiate the default type. Any forward reference to a type
-                        // parameter should be instantiated to the empty object type.
-                        inferredType = instantiateType(defaultType,
-                            combineTypeMappers(
-                                createBackreferenceMapper(context.signature.typeParameters, index),
-                                getInferenceMapper(context)));
+                    if (context.flags & InferenceFlags.NoDefault) {
+                        // We use silentNeverType as the wildcard that signals no inferences.
+                        inferredType = silentNeverType;
                     }
                     else {
-                        inferredType = context.noInferenceType;
+                        // Infer either the default or the empty object type when no inferences were
+                        // made. It is important to remember that in this case, inference still
+                        // succeeds, meaning there is no error for not having inference candidates. An
+                        // inference error only occurs when there are *conflicting* candidates, i.e.
+                        // candidates with no common supertype.
+                        const defaultType = getDefaultFromTypeParameter(inference.typeParameter);
+                        if (defaultType) {
+                            // Instantiate the default type. Any forward reference to a type
+                            // parameter should be instantiated to the empty object type.
+                            inferredType = instantiateType(defaultType,
+                                combineTypeMappers(
+                                    createBackreferenceMapper(context.signature.typeParameters, index),
+                                    getInferenceMapper(context)));
+                        }
+                        else {
+                            inferredType = context.flags & InferenceFlags.AnyDefault ? anyType : emptyObjectType;
+                        }
                     }
-
                     inferenceSucceeded = true;
                 }
                 inference.inferredType = inferredType;
@@ -14872,10 +14876,10 @@ namespace ts {
 
         // Instantiate a generic signature in the context of a non-generic signature (section 3.8.5 in TypeScript spec)
         function instantiateSignatureInContextOf(signature: Signature, contextualSignature: Signature, contextualMapper: TypeMapper): Signature {
-            const context = createInferenceContext(/*callNode*/ undefined, signature, /*inferUnionTypes*/ true, /*noInferenceType*/ emptyObjectType);
+            const context = createInferenceContext(/*callNode*/ undefined, signature, InferenceFlags.InferUnionTypes);
             forEachMatchingParameterType(contextualSignature, signature, (source, target) => {
                 // Type parameters from outer context referenced by source type are fixed by instantiation of the source type
-                inferTypesWithContext(context, instantiateType(source, contextualMapper), target);
+                inferTypes(context.inferences, instantiateType(source, contextualMapper), target);
             });
             return getSignatureInstantiation(signature, getInferredTypes(context));
         }
@@ -14910,7 +14914,7 @@ namespace ts {
             if (thisType) {
                 const thisArgumentNode = getThisArgumentOfCall(node);
                 const thisArgumentType = thisArgumentNode ? checkExpression(thisArgumentNode) : voidType;
-                inferTypesWithContext(context, thisArgumentType, thisType);
+                inferTypes(context.inferences, thisArgumentType, thisType);
             }
 
             // We perform two passes over the arguments. In the first pass we infer from all arguments, but use
@@ -14932,7 +14936,7 @@ namespace ts {
                         argType = checkExpressionWithContextualType(arg, paramType, mapper);
                     }
 
-                    inferTypesWithContext(context, argType, paramType);
+                    inferTypes(context.inferences, argType, paramType);
                 }
             }
 
@@ -14947,7 +14951,7 @@ namespace ts {
                     if (excludeArgument[i] === false) {
                         const arg = args[i];
                         const paramType = getTypeAtPosition(signature, i);
-                        inferTypesWithContext(context, checkExpressionWithContextualType(arg, paramType, inferenceMapper), paramType);
+                        inferTypes(context.inferences, checkExpressionWithContextualType(arg, paramType, inferenceMapper), paramType);
                     }
                 }
             }
@@ -15606,7 +15610,7 @@ namespace ts {
                     let candidate: Signature;
                     let typeArgumentsAreValid: boolean;
                     const inferenceContext = originalCandidate.typeParameters
-                        ? createInferenceContext(node, originalCandidate, /*inferUnionTypes*/ false, /*noInferenceType*/ isInJavaScriptFile(node) ? anyType : emptyObjectType)
+                        ? createInferenceContext(node, originalCandidate, /*flags*/ isInJavaScriptFile(node) ? InferenceFlags.AnyDefault : 0)
                         : undefined;
 
                     while (true) {
@@ -16192,7 +16196,7 @@ namespace ts {
                 for (let i = 0; i < len; i++) {
                     const declaration = <ParameterDeclaration>signature.parameters[i].valueDeclaration;
                     if (declaration.type) {
-                        inferTypesWithContext(mapper.context, getTypeFromTypeNode(declaration.type), getTypeAtPosition(context, i));
+                        inferTypes(mapper.context.inferences, getTypeFromTypeNode(declaration.type), getTypeAtPosition(context, i));
                     }
                 }
             }
@@ -16278,7 +16282,7 @@ namespace ts {
                 // T in the second overload so that we do not infer Base as a candidate for T
                 // (inferring Base would make type argument inference inconsistent between the two
                 // overloads).
-                inferTypesWithContext(mapper.context, links.type, instantiateType(contextualType, mapper));
+                inferTypes(mapper.context.inferences, links.type, instantiateType(contextualType, mapper));
             }
         }
 
diff --git a/src/compiler/types.ts b/src/compiler/types.ts
index 5e5c2851bf8..08cccd35d7a 100644
--- a/src/compiler/types.ts
+++ b/src/compiler/types.ts
@@ -3356,14 +3356,19 @@ namespace ts {
         isFixed: boolean;
     }
 
+    export const enum InferenceFlags {
+        InferUnionTypes = 1 << 0,  // Infer union types for disjoint candidates (otherwise unknownType)
+        NoDefault       = 1 << 1,  // Infer unknownType for no inferences (otherwise anyType or emptyObjectType)
+        AnyDefault      = 1 << 2,  // Infer anyType for no inferences (otherwise emptyObjectType)
+    }
+
     /* @internal */
     export interface InferenceContext {
         callNode: CallLikeExpression;       // Call expression node for which inferences are made
         signature: Signature;               // Generic signature for which inferences are made
         inferences: InferenceInfo[];        // Inferences made for each type parameter
+        flags: InferenceFlags;              // Infer union types for disjoint candidates (otherwise undefinedType)
         mapper?: TypeMapper;                // Type mapper for this inference context
-        inferUnionTypes: boolean;           // Infer union types for disjoint candidates (otherwise undefinedType)
-        noInferenceType: Type;              // Type to use for no inferences
         failedTypeParameterIndex?: number;  // Index of type parameter for which inference failed
         // It is optional because in contextual signature instantiation, nothing fails
     }

From 7dd9e2156cb410ecad0d40787e96bf814c467e6d Mon Sep 17 00:00:00 2001
From: Anders Hejlsberg <andersh@microsoft.com>
Date: Mon, 22 May 2017 14:56:20 -0700
Subject: [PATCH 04/56] Accept new baselines

---
 tests/baselines/reference/implicitAnyGenerics.types      | 2 +-
 .../reference/recursiveTypeComparison2.errors.txt        | 9 ++-------
 2 files changed, 3 insertions(+), 8 deletions(-)

diff --git a/tests/baselines/reference/implicitAnyGenerics.types b/tests/baselines/reference/implicitAnyGenerics.types
index 1202c73c51a..e6237e9f3a2 100644
--- a/tests/baselines/reference/implicitAnyGenerics.types
+++ b/tests/baselines/reference/implicitAnyGenerics.types
@@ -26,7 +26,7 @@ var c3 = new C<number>();
 var c4: C<any> = new C();
 >c4 : C<any>
 >C : C<T>
->new C() : C<{}>
+>new C() : C<any>
 >C : typeof C
 
 class D<T> {
diff --git a/tests/baselines/reference/recursiveTypeComparison2.errors.txt b/tests/baselines/reference/recursiveTypeComparison2.errors.txt
index 71f337ad15f..5c1200ceec6 100644
--- a/tests/baselines/reference/recursiveTypeComparison2.errors.txt
+++ b/tests/baselines/reference/recursiveTypeComparison2.errors.txt
@@ -1,9 +1,7 @@
 tests/cases/compiler/recursiveTypeComparison2.ts(13,80): error TS2304: Cannot find name 'StateValue'.
-tests/cases/compiler/recursiveTypeComparison2.ts(30,5): error TS2322: Type 'Bus<{}>' is not assignable to type 'Bus<number>'.
-  Type '{}' is not assignable to type 'number'.
 
 
-==== tests/cases/compiler/recursiveTypeComparison2.ts (2 errors) ====
+==== tests/cases/compiler/recursiveTypeComparison2.ts (1 errors) ====
     // Before fix this would cause compiler to hang (#1170)
     
     declare module Bacon {
@@ -35,7 +33,4 @@ tests/cases/compiler/recursiveTypeComparison2.ts(30,5): error TS2322: Type 'Bus<
         var Bus: new <T>() => Bus<T>;
     }
     
-    var stuck: Bacon.Bus<number> = new Bacon.Bus();
-        ~~~~~
-!!! error TS2322: Type 'Bus<{}>' is not assignable to type 'Bus<number>'.
-!!! error TS2322:   Type '{}' is not assignable to type 'number'.
\ No newline at end of file
+    var stuck: Bacon.Bus<number> = new Bacon.Bus();
\ No newline at end of file

From 0b37adc3a7fe1cbfa8685818ef92a436e53af773 Mon Sep 17 00:00:00 2001
From: Anders Hejlsberg <andersh@microsoft.com>
Date: Mon, 22 May 2017 16:48:45 -0700
Subject: [PATCH 05/56] Fix fourslash test

---
 tests/cases/fourslash/genericCombinators2.ts | 37 ++++++++++----------
 1 file changed, 18 insertions(+), 19 deletions(-)

diff --git a/tests/cases/fourslash/genericCombinators2.ts b/tests/cases/fourslash/genericCombinators2.ts
index a5cea186789..aedadfa301e 100644
--- a/tests/cases/fourslash/genericCombinators2.ts
+++ b/tests/cases/fourslash/genericCombinators2.ts
@@ -1,48 +1,48 @@
 /// <reference path='fourslash.ts'/>
 
 ////interface Collection<T, U> {
-////    length: number;
-////    add(x: T, y: U): void ;
-////    remove(x: T, y: U): boolean;
-////}
+////   length: number;
+////   add(x: T, y: U): void ;
+////   remove(x: T, y: U): boolean;
 ////}
+////
 ////interface Combinators {
-////    map<T, U, V>(c: Collection<T, U>, f: (x: T, y: U) => V): Collection<T, V>;
-////    map<T, U>(c: Collection<T, U>, f: (x: T, y: U) => any): Collection<any, any>;
-////}
+////   map<T, U, V>(c: Collection<T, U>, f: (x: T, y: U) => V): Collection<T, V>;
+////   map<T, U>(c: Collection<T, U>, f: (x: T, y: U) => any): Collection<any, any>;
 ////}
+////
 ////class A {
-////    foo<T>(): T { return null; }
-////}
+////   foo<T>(): T { return null; }
 ////}
+////
 ////class B<T> {
-////    foo(x: T): T { return null; }
-////}
+////   foo(x: T): T { return null; }
 ////}
+////
 ////var c1: Collection<any, any>;
 ////var c2: Collection<number, string>;
 ////var c3: Collection<Collection<number, number>, string>;
 ////var c4: Collection<number, A>;
 ////var c5: Collection<number, B<any>>;
-////}
+////
 ////var _: Combinators;
 ////// param help on open paren for arg 2 should show 'number' not T or 'any'
 ////// x should be contextually typed to number
 ////var rf1 = (x: number, y: string) => { return x.toFixed() };
 ////var rf2 = (x: Collection<number, number>, y: string) => { return x.length };
 ////var rf3 = (x: number, y: A) => { return y.foo() };
-////}
+////
 ////var /*9*/r1a  = _.map/*1c*/(c2, (/*1a*/x, /*1b*/y) => { return x.toFixed() });
 ////var /*10*/r1b = _.map(c2, rf1);
-////}
+////
 ////var /*11*/r2a = _.map(c3, (/*2a*/x, /*2b*/y) => { return x.length });
 ////var /*12*/r2b = _.map(c3, rf2);
-////}
+////
 ////var /*13*/r3a = _.map(c4, (/*3a*/x, /*3b*/y) => { return y.foo() });
 ////var /*14*/r3b = _.map(c4, rf3);
-////}
+////
 ////var /*15*/r4a = _.map(c5, (/*4a*/x, /*4b*/y) => { return y.foo() });
-////}
+////
 ////var /*17*/r5a = _.map<number, string, Date>(c2, /*17error1*/(/*5a*/x, /*5b*/y) => { return x.toFixed() }/*17error2*/); 
 ////var rf1b = (x: number, y: string) => { return new Date() };
 ////var /*18*/r5b = _.map<number, string, Date>(c2, rf1b);
@@ -51,7 +51,7 @@
 ////var rf2b = (x: Collection<number, number>, y: string) => { return new Date(); };
 ////var /*20*/r6b = _.map<Collection<number, number>, string, Date>(c3, rf2b);
 ////
-////var /*21*/r7a = _.map<number, A, string>(c4, /*21error1*/(/*7a*/x,/*7b*/y) => { return y.foo() }/*21error2*/);
+////var /*21*/r7a = _.map<number, A, string>(c4, (/*7a*/x,/*7b*/y) => { return y.foo() });
 ////var /*22*/r7b = _.map<number, A, string>(c4, /*22error1*/rf3/*22error2*/);
 ////
 ////var /*23*/r8a = _.map<number, /*error1*/B/*error2*/, string>(c5, (/*8a*/x,/*8b*/y) => { return y.foo() }); 
@@ -89,5 +89,4 @@ verify.quickInfos({
 
 verify.errorExistsBetweenMarkers('error1', 'error2');
 verify.errorExistsBetweenMarkers('17error1', '17error2');
-verify.errorExistsBetweenMarkers('21error1', '21error2');
 verify.errorExistsBetweenMarkers('22error1', '22error2');
\ No newline at end of file

From 501d92a0494412ead4728502eb63c226664cb071 Mon Sep 17 00:00:00 2001
From: Anders Hejlsberg <andersh@microsoft.com>
Date: Mon, 22 May 2017 16:48:57 -0700
Subject: [PATCH 06/56] Fix linting errors

---
 src/compiler/checker.ts | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 8c42d890665..de0feae2f08 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -10159,8 +10159,8 @@ namespace ts {
                 callNode: context.callNode,
                 signature: context.signature,
                 inferences: map(context.inferences, cloneInferenceInfo),
-                flags: context.flags | InferenceFlags.NoDefault,
-            }
+                flags: context.flags | InferenceFlags.NoDefault
+            };
         }
 
         function cloneInferenceInfo(inference: InferenceInfo): InferenceInfo {
@@ -10617,7 +10617,7 @@ namespace ts {
         }
 
         function getInferredTypes(context: InferenceContext): Type[] {
-            let result = [];
+            const result: Type[] = [];
             for (let i = 0; i < context.inferences.length; i++) {
                 result.push(getInferredType(context, i));
             }

From 7b0bd090e28c5e19143c2823dfcc10c5ea4e392e Mon Sep 17 00:00:00 2001
From: Andy Hanson <anhans@microsoft.com>
Date: Tue, 23 May 2017 08:52:55 -0700
Subject: [PATCH 07/56] findAllReferences: Make "isWriteAccess" handle special
 declaration kinds

---
 src/compiler/checker.ts                       |  4 ++--
 src/compiler/utilities.ts                     | 17 ++++++++++++++
 src/services/findAllReferences.ts             | 22 +++++++++----------
 .../fourslash/findAllRefsForModuleGlobal.ts   |  2 +-
 ...rencesIsDefinitionOfNumberNamedProperty.ts |  2 +-
 ...rencesIsDefinitionOfStringNamedProperty.ts |  2 +-
 .../cases/fourslash/referencesBloomFilters.ts |  2 +-
 .../fourslash/referencesBloomFilters2.ts      |  4 ++--
 .../fourslash/referencesBloomFilters3.ts      |  2 +-
 .../cases/fourslash/referencesForAmbients.ts  |  4 ++--
 tests/cases/fourslash/referencesForEnums.ts   |  4 ++--
 .../referencesForExternalModuleNames.ts       |  2 +-
 ...eferencesForNumericLiteralPropertyNames.ts |  6 ++---
 ...referencesForStringLiteralPropertyNames.ts |  4 ++--
 ...eferencesForStringLiteralPropertyNames2.ts |  2 +-
 ...eferencesForStringLiteralPropertyNames3.ts |  4 ++--
 ...eferencesForStringLiteralPropertyNames4.ts |  2 +-
 tests/cases/fourslash/renameJsExports01.ts    |  2 +-
 18 files changed, 51 insertions(+), 36 deletions(-)

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 8551652c176..46f56d99b39 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -12750,7 +12750,7 @@ namespace ts {
         function getContextualTypeForBinaryOperand(node: Expression): Type {
             const binaryExpression = <BinaryExpression>node.parent;
             const operator = binaryExpression.operatorToken.kind;
-            if (operator >= SyntaxKind.FirstAssignment && operator <= SyntaxKind.LastAssignment) {
+            if (isAssignmentOperator(operator)) {
                 // Don't do this for special property assignments to avoid circularity
                 if (getSpecialPropertyAssignmentKind(binaryExpression) !== SpecialPropertyAssignmentKind.None) {
                     return undefined;
@@ -17305,7 +17305,7 @@ namespace ts {
             }
 
             function checkAssignmentOperator(valueType: Type): void {
-                if (produceDiagnostics && operator >= SyntaxKind.FirstAssignment && operator <= SyntaxKind.LastAssignment) {
+                if (produceDiagnostics && isAssignmentOperator(operator)) {
                     // TypeScript 1.0 spec (April 2014): 4.17
                     // An assignment of the form
                     //    VarExpr = ValueExpr
diff --git a/src/compiler/utilities.ts b/src/compiler/utilities.ts
index a5750248707..3a8b8b59f7d 100644
--- a/src/compiler/utilities.ts
+++ b/src/compiler/utilities.ts
@@ -1785,6 +1785,23 @@ namespace ts {
         }
     }
 
+    /* @internal */
+    // See GH#16030
+    export function isAnyDeclarationName(name: Node): boolean {
+        switch (name.kind) {
+            case SyntaxKind.Identifier:
+            case SyntaxKind.StringLiteral:
+            case SyntaxKind.NumericLiteral:
+                if (isDeclaration(name.parent)) {
+                    return name.parent.name === name;
+                }
+                const binExp = name.parent.parent;
+                return isBinaryExpression(binExp) && getSpecialPropertyAssignmentKind(binExp) !== SpecialPropertyAssignmentKind.None && getNameOfDeclaration(binExp) === name;
+            default:
+                return false;
+        }
+    }
+
     export function isLiteralComputedPropertyDeclarationName(node: Node) {
         return (node.kind === SyntaxKind.StringLiteral || node.kind === SyntaxKind.NumericLiteral) &&
             node.parent.kind === SyntaxKind.ComputedPropertyName &&
diff --git a/src/services/findAllReferences.ts b/src/services/findAllReferences.ts
index fd564cac13d..efc6a6f6ed1 100644
--- a/src/services/findAllReferences.ts
+++ b/src/services/findAllReferences.ts
@@ -176,7 +176,7 @@ namespace ts.FindAllReferences {
             fileName: node.getSourceFile().fileName,
             textSpan: getTextSpan(node),
             isWriteAccess: isWriteAccess(node),
-            isDefinition: isDeclarationName(node) || isLiteralComputedPropertyDeclarationName(node),
+            isDefinition: isAnyDeclarationName(node) || isLiteralComputedPropertyDeclarationName(node),
             isInString
         };
     }
@@ -242,22 +242,20 @@ namespace ts.FindAllReferences {
 
     /** A node is considered a writeAccess iff it is a name of a declaration or a target of an assignment */
     function isWriteAccess(node: Node): boolean {
-        if (node.kind === SyntaxKind.Identifier && isDeclarationName(node)) {
+        if (isAnyDeclarationName(node)) {
             return true;
         }
 
-        const parent = node.parent;
-        if (parent) {
-            if (parent.kind === SyntaxKind.PostfixUnaryExpression || parent.kind === SyntaxKind.PrefixUnaryExpression) {
+        const { parent } = node;
+        switch (parent && parent.kind) {
+            case SyntaxKind.PostfixUnaryExpression:
+            case SyntaxKind.PrefixUnaryExpression:
                 return true;
-            }
-            else if (parent.kind === SyntaxKind.BinaryExpression && (<BinaryExpression>parent).left === node) {
-                const operator = (<BinaryExpression>parent).operatorToken.kind;
-                return SyntaxKind.FirstAssignment <= operator && operator <= SyntaxKind.LastAssignment;
-            }
+            case SyntaxKind.BinaryExpression:
+                return (<BinaryExpression>parent).left === node && isAssignmentOperator((<BinaryExpression>parent).operatorToken.kind);
+            default:
+                return false;
         }
-
-        return false;
     }
 }
 
diff --git a/tests/cases/fourslash/findAllRefsForModuleGlobal.ts b/tests/cases/fourslash/findAllRefsForModuleGlobal.ts
index 25c23faeae5..4c1b39cdb0f 100644
--- a/tests/cases/fourslash/findAllRefsForModuleGlobal.ts
+++ b/tests/cases/fourslash/findAllRefsForModuleGlobal.ts
@@ -6,7 +6,7 @@
 // @Filename: /b.ts
 /////// <reference types="[|foo|]" />
 ////import { x } from "[|foo|]";
-////declare module "[|{| "isDefinition": true |}foo|]" {}
+////declare module "[|{| "isWriteAccess": true, "isDefinition": true |}foo|]" {}
 
 verify.noErrors();
 
diff --git a/tests/cases/fourslash/getOccurrencesIsDefinitionOfNumberNamedProperty.ts b/tests/cases/fourslash/getOccurrencesIsDefinitionOfNumberNamedProperty.ts
index c603f398e5e..b391deec9cc 100644
--- a/tests/cases/fourslash/getOccurrencesIsDefinitionOfNumberNamedProperty.ts
+++ b/tests/cases/fourslash/getOccurrencesIsDefinitionOfNumberNamedProperty.ts
@@ -1,5 +1,5 @@
 /// <reference path='fourslash.ts' />
-////let o = { [|{| "isDefinition": true |}1|]: 12 };
+////let o = { [|{| "isWriteAccess": true, "isDefinition": true |}1|]: 12 };
 ////let y = o[[|1|]];
 
 const ranges = test.ranges();
diff --git a/tests/cases/fourslash/getOccurrencesIsDefinitionOfStringNamedProperty.ts b/tests/cases/fourslash/getOccurrencesIsDefinitionOfStringNamedProperty.ts
index 43fe0c571fc..4b842da6f59 100644
--- a/tests/cases/fourslash/getOccurrencesIsDefinitionOfStringNamedProperty.ts
+++ b/tests/cases/fourslash/getOccurrencesIsDefinitionOfStringNamedProperty.ts
@@ -1,5 +1,5 @@
 /// <reference path='fourslash.ts' />
-////let o = { "[|{| "isDefinition": true |}x|]": 12 };
+////let o = { "[|{| "isWriteAccess": true, "isDefinition": true |}x|]": 12 };
 ////let y = o.[|x|];
 
 const ranges = test.ranges();
diff --git a/tests/cases/fourslash/referencesBloomFilters.ts b/tests/cases/fourslash/referencesBloomFilters.ts
index c9f290db0db..2745f6144ca 100644
--- a/tests/cases/fourslash/referencesBloomFilters.ts
+++ b/tests/cases/fourslash/referencesBloomFilters.ts
@@ -12,7 +12,7 @@
 ////function blah2() { container["[|searchProp|]"] };
 
 // @Filename: redeclaration.ts
-////container = { "[|{| "isDefinition": true |}searchProp|]" : 18 };
+////container = { "[|{| "isWriteAccess": true, "isDefinition": true |}searchProp|]" : 18 };
 
 const ranges = test.ranges();
 const [r0, r1, r2, r3] = ranges;
diff --git a/tests/cases/fourslash/referencesBloomFilters2.ts b/tests/cases/fourslash/referencesBloomFilters2.ts
index daf60d0dd01..26690e437ee 100644
--- a/tests/cases/fourslash/referencesBloomFilters2.ts
+++ b/tests/cases/fourslash/referencesBloomFilters2.ts
@@ -3,7 +3,7 @@
 // Ensure BloomFilter building logic is correct, by having one reference per file
 
 // @Filename: declaration.ts
-////var container = { [|{| "isDefinition": true |}42|]: 1 };
+////var container = { [|{| "isWriteAccess": true, "isDefinition": true |}42|]: 1 };
 
 // @Filename: expression.ts
 ////function blah() { return (container[[|42|]]) === 2;  };
@@ -12,7 +12,7 @@
 ////function blah2() { container["[|42|]"] };
 
 // @Filename: redeclaration.ts
-////container = { "[|{| "isDefinition": true |}42|]" : 18 };
+////container = { "[|{| "isWriteAccess": true, "isDefinition": true |}42|]" : 18 };
 
 const ranges = test.ranges();
 const [r0, r1, r2, r3] = ranges;
diff --git a/tests/cases/fourslash/referencesBloomFilters3.ts b/tests/cases/fourslash/referencesBloomFilters3.ts
index 0dd5c645264..d7d335cde02 100644
--- a/tests/cases/fourslash/referencesBloomFilters3.ts
+++ b/tests/cases/fourslash/referencesBloomFilters3.ts
@@ -4,7 +4,7 @@
 
 
 // @Filename: declaration.ts
-////enum Test { "[|{| "isDefinition": true |}42|]" = 1 };
+////enum Test { "[|{| "isWriteAccess": true, "isDefinition": true |}42|]" = 1 };
 
 // @Filename: expression.ts
 ////(Test[[|42|]]);
diff --git a/tests/cases/fourslash/referencesForAmbients.ts b/tests/cases/fourslash/referencesForAmbients.ts
index f5789716155..2397738581e 100644
--- a/tests/cases/fourslash/referencesForAmbients.ts
+++ b/tests/cases/fourslash/referencesForAmbients.ts
@@ -1,10 +1,10 @@
 /// <reference path='fourslash.ts'/>
 
-////declare module "[|{| "isDefinition": true |}foo|]" {
+////declare module "[|{| "isWriteAccess": true, "isDefinition": true |}foo|]" {
 ////    var [|{| "isWriteAccess": true, "isDefinition": true |}f|]: number;
 ////}
 ////
-////declare module "[|{| "isDefinition": true |}bar|]" {
+////declare module "[|{| "isWriteAccess": true, "isDefinition": true |}bar|]" {
 ////    export import [|{| "isWriteAccess": true, "isDefinition": true |}foo|] = require("[|foo|]");
 ////    var f2: typeof [|foo|].[|f|];
 ////}
diff --git a/tests/cases/fourslash/referencesForEnums.ts b/tests/cases/fourslash/referencesForEnums.ts
index 68face36d04..af4fec8aae8 100644
--- a/tests/cases/fourslash/referencesForEnums.ts
+++ b/tests/cases/fourslash/referencesForEnums.ts
@@ -2,8 +2,8 @@
 
 ////enum E {
 ////    [|{| "isWriteAccess": true, "isDefinition": true |}value1|] = 1,
-////    "[|{| "isDefinition": true |}value2|]" = [|value1|],
-////    [|{| "isDefinition": true |}111|] = 11
+////    "[|{| "isWriteAccess": true, "isDefinition": true |}value2|]" = [|value1|],
+////    [|{| "isWriteAccess": true, "isDefinition": true |}111|] = 11
 ////}
 ////
 ////E.[|value1|];
diff --git a/tests/cases/fourslash/referencesForExternalModuleNames.ts b/tests/cases/fourslash/referencesForExternalModuleNames.ts
index 75ea9e908cf..127aa9fd657 100644
--- a/tests/cases/fourslash/referencesForExternalModuleNames.ts
+++ b/tests/cases/fourslash/referencesForExternalModuleNames.ts
@@ -3,7 +3,7 @@
 // Global interface reference.
 
 // @Filename: referencesForGlobals_1.ts
-////declare module "[|{| "isDefinition": true |}foo|]" {
+////declare module "[|{| "isWriteAccess": true, "isDefinition": true |}foo|]" {
 ////    var f: number;
 ////}
 
diff --git a/tests/cases/fourslash/referencesForNumericLiteralPropertyNames.ts b/tests/cases/fourslash/referencesForNumericLiteralPropertyNames.ts
index effa4abc164..a869ba8bcc1 100644
--- a/tests/cases/fourslash/referencesForNumericLiteralPropertyNames.ts
+++ b/tests/cases/fourslash/referencesForNumericLiteralPropertyNames.ts
@@ -1,13 +1,13 @@
 /// <reference path='fourslash.ts'/>
 
 ////class Foo {
-////    public [|{| "isDefinition": true |}12|]: any;
+////    public [|{| "isWriteAccess": true, "isDefinition": true |}12|]: any;
 ////}
 ////
 ////var x: Foo;
 ////x[[|12|]];
-////x = { "[|{| "isDefinition": true |}12|]": 0 };
-////x = { [|{| "isDefinition": true |}12|]: 0 };
+////x = { "[|{| "isWriteAccess": true, "isDefinition": true |}12|]": 0 };
+////x = { [|{| "isWriteAccess": true, "isDefinition": true |}12|]: 0 };
 
 //verify.singleReferenceGroup("(property) Foo[12]: any");
 const ranges = test.ranges();
diff --git a/tests/cases/fourslash/referencesForStringLiteralPropertyNames.ts b/tests/cases/fourslash/referencesForStringLiteralPropertyNames.ts
index e9be352f819..c5ae2f0c586 100644
--- a/tests/cases/fourslash/referencesForStringLiteralPropertyNames.ts
+++ b/tests/cases/fourslash/referencesForStringLiteralPropertyNames.ts
@@ -1,13 +1,13 @@
 /// <reference path='fourslash.ts'/>
 
 ////class Foo {
-////    public "[|{| "isDefinition": true |}ss|]": any;
+////    public "[|{| "isWriteAccess": true, "isDefinition": true |}ss|]": any;
 ////}
 ////
 ////var x: Foo;
 ////x.[|ss|];
 ////x["[|ss|]"];
-////x = { "[|{| "isDefinition": true |}ss|]": 0 };
+////x = { "[|{| "isWriteAccess": true, "isDefinition": true |}ss|]": 0 };
 ////x = { [|{| "isWriteAccess": true, "isDefinition": true |}ss|]: 0 };
 
 const ranges = test.ranges();
diff --git a/tests/cases/fourslash/referencesForStringLiteralPropertyNames2.ts b/tests/cases/fourslash/referencesForStringLiteralPropertyNames2.ts
index 6fbb0b85072..89b6c7c755e 100644
--- a/tests/cases/fourslash/referencesForStringLiteralPropertyNames2.ts
+++ b/tests/cases/fourslash/referencesForStringLiteralPropertyNames2.ts
@@ -1,7 +1,7 @@
 /// <reference path='fourslash.ts'/>
 
 ////class Foo {
-////    "[|{| "isDefinition": true |}blah|]"() { return 0; }
+////    "[|{| "isWriteAccess": true, "isDefinition": true |}blah|]"() { return 0; }
 ////}
 ////
 ////var x: Foo;
diff --git a/tests/cases/fourslash/referencesForStringLiteralPropertyNames3.ts b/tests/cases/fourslash/referencesForStringLiteralPropertyNames3.ts
index d4e12a67afc..aae15afd0c7 100644
--- a/tests/cases/fourslash/referencesForStringLiteralPropertyNames3.ts
+++ b/tests/cases/fourslash/referencesForStringLiteralPropertyNames3.ts
@@ -1,8 +1,8 @@
 /// <reference path='fourslash.ts'/>
 
 ////class Foo2 {
-////    get "[|{| "isDefinition": true |}42|]"() { return 0; }
-////    set [|{| "isDefinition": true |}42|](n) { }
+////    get "[|{| "isWriteAccess": true, "isDefinition": true |}42|]"() { return 0; }
+////    set [|{| "isWriteAccess": true, "isDefinition": true |}42|](n) { }
 ////}
 ////
 ////var y: Foo2;
diff --git a/tests/cases/fourslash/referencesForStringLiteralPropertyNames4.ts b/tests/cases/fourslash/referencesForStringLiteralPropertyNames4.ts
index efe8972f2c7..4293435de1d 100644
--- a/tests/cases/fourslash/referencesForStringLiteralPropertyNames4.ts
+++ b/tests/cases/fourslash/referencesForStringLiteralPropertyNames4.ts
@@ -1,6 +1,6 @@
 /// <reference path='fourslash.ts'/>
 
-////var x = { "[|{| "isDefinition": true |}someProperty|]": 0 }
+////var x = { "[|{| "isWriteAccess": true, "isDefinition": true |}someProperty|]": 0 }
 ////x["[|someProperty|]"] = 3;
 ////x.[|someProperty|] = 5;
 
diff --git a/tests/cases/fourslash/renameJsExports01.ts b/tests/cases/fourslash/renameJsExports01.ts
index b731ece63f3..e1b71d232a6 100644
--- a/tests/cases/fourslash/renameJsExports01.ts
+++ b/tests/cases/fourslash/renameJsExports01.ts
@@ -2,7 +2,7 @@
 
 // @allowJs: true
 // @Filename: a.js
-////exports.[|area|] = function (r) { return r * r; }
+////exports.[|{| "isWriteAccess": true, "isDefinition": true |}area|] = function (r) { return r * r; }
 
 // @Filename: b.js
 ////var mod = require('./a');

From e4aa515191f0817ca64374e3da1e80418f8444b0 Mon Sep 17 00:00:00 2001
From: Yui <yuit@users.noreply.github.com>
Date: Tue, 23 May 2017 10:24:46 -0700
Subject: [PATCH 08/56] [Master] Fix 15179 missing comment in switch case
 clause (#16033)

* Fix emit comments after switch case clause

* Update baselines

* Add new tests and baselines
---
 src/compiler/emitter.ts                       | 16 ++++++++
 .../reference/commentsAfterCaseClauses1.js    | 31 ++++++++++++++
 .../commentsAfterCaseClauses1.symbols         | 20 +++++++++
 .../reference/commentsAfterCaseClauses1.types | 37 +++++++++++++++++
 .../reference/commentsAfterCaseClauses2.js    | 36 ++++++++++++++++
 .../commentsAfterCaseClauses2.symbols         | 23 +++++++++++
 .../reference/commentsAfterCaseClauses2.types | 41 +++++++++++++++++++
 .../reference/commentsAfterCaseClauses3.js    | 34 +++++++++++++++
 .../commentsAfterCaseClauses3.symbols         | 22 ++++++++++
 .../reference/commentsAfterCaseClauses3.types | 39 ++++++++++++++++++
 .../baselines/reference/parserRealSource1.js  | 16 ++++----
 tests/baselines/reference/parserindenter.js   |  8 ++--
 .../switchStatementsWithMultipleDefaults.js   |  6 +--
 .../switchStatementsWithMultipleDefaults1.js  |  2 +-
 .../compiler/commentsAfterCaseClauses1.ts     | 14 +++++++
 .../compiler/commentsAfterCaseClauses2.ts     | 17 ++++++++
 .../compiler/commentsAfterCaseClauses3.ts     | 16 ++++++++
 17 files changed, 362 insertions(+), 16 deletions(-)
 create mode 100644 tests/baselines/reference/commentsAfterCaseClauses1.js
 create mode 100644 tests/baselines/reference/commentsAfterCaseClauses1.symbols
 create mode 100644 tests/baselines/reference/commentsAfterCaseClauses1.types
 create mode 100644 tests/baselines/reference/commentsAfterCaseClauses2.js
 create mode 100644 tests/baselines/reference/commentsAfterCaseClauses2.symbols
 create mode 100644 tests/baselines/reference/commentsAfterCaseClauses2.types
 create mode 100644 tests/baselines/reference/commentsAfterCaseClauses3.js
 create mode 100644 tests/baselines/reference/commentsAfterCaseClauses3.symbols
 create mode 100644 tests/baselines/reference/commentsAfterCaseClauses3.types
 create mode 100644 tests/cases/compiler/commentsAfterCaseClauses1.ts
 create mode 100644 tests/cases/compiler/commentsAfterCaseClauses2.ts
 create mode 100644 tests/cases/compiler/commentsAfterCaseClauses3.ts

diff --git a/src/compiler/emitter.ts b/src/compiler/emitter.ts
index 0348469dae1..c0b0d170de8 100644
--- a/src/compiler/emitter.ts
+++ b/src/compiler/emitter.ts
@@ -2021,6 +2021,22 @@ namespace ts {
                     rangeStartPositionsAreOnSameLine(parentNode, statements[0], currentSourceFile)
                 );
 
+            // e.g:
+            //      case 0: // Zero
+            //      case 1: // One
+            //      case 2: // two
+            //          return "hi";
+            // If there is no statements, emitNodeWithComments of the parentNode which is caseClause will take care of trailing comment.
+            // So in example above, comment "// Zero" and "// One" will be emit in emitTrailingComments in emitNodeWithComments.
+            // However, for "case 2", because parentNode which is caseClause has an "end" property to be end of the statements (in this case return statement)
+            // comment "// two" will not be emitted in emitNodeWithComments.
+            // Therefore, we have to do the check here to emit such comment.
+            if (statements.length > 0) {
+                // We use emitTrailingCommentsOfPosition instead of emitLeadingCommentsOfPosition because leading comments is defined as comments before the node after newline character separating it from previous line
+                // Note: we can't use parentNode.end as such position includes statements.
+                emitTrailingCommentsOfPosition(statements.pos);
+            }
+
             if (emitAsSingleStatement) {
                 write(" ");
                 emit(statements[0]);
diff --git a/tests/baselines/reference/commentsAfterCaseClauses1.js b/tests/baselines/reference/commentsAfterCaseClauses1.js
new file mode 100644
index 00000000000..e12fe703335
--- /dev/null
+++ b/tests/baselines/reference/commentsAfterCaseClauses1.js
@@ -0,0 +1,31 @@
+//// [commentsAfterCaseClauses1.ts]
+function getSecurity(level) {
+    switch(level){
+        case 0: // Zero
+        case 1: // one
+        case 2: // two
+            return "Hi";
+        case 3: // three
+        case 4   : // four
+            return "hello";
+        case 5: // five
+        default:  // default
+            return "world";
+    }
+}
+
+//// [commentsAfterCaseClauses1.js]
+function getSecurity(level) {
+    switch (level) {
+        case 0: // Zero
+        case 1: // one
+        case 2:// two
+            return "Hi";
+        case 3: // three
+        case 4:// four
+            return "hello";
+        case 5: // five
+        default:// default
+            return "world";
+    }
+}
diff --git a/tests/baselines/reference/commentsAfterCaseClauses1.symbols b/tests/baselines/reference/commentsAfterCaseClauses1.symbols
new file mode 100644
index 00000000000..1ca620c4eb4
--- /dev/null
+++ b/tests/baselines/reference/commentsAfterCaseClauses1.symbols
@@ -0,0 +1,20 @@
+=== tests/cases/compiler/commentsAfterCaseClauses1.ts ===
+function getSecurity(level) {
+>getSecurity : Symbol(getSecurity, Decl(commentsAfterCaseClauses1.ts, 0, 0))
+>level : Symbol(level, Decl(commentsAfterCaseClauses1.ts, 0, 21))
+
+    switch(level){
+>level : Symbol(level, Decl(commentsAfterCaseClauses1.ts, 0, 21))
+
+        case 0: // Zero
+        case 1: // one
+        case 2: // two
+            return "Hi";
+        case 3: // three
+        case 4   : // four
+            return "hello";
+        case 5: // five
+        default:  // default
+            return "world";
+    }
+}
diff --git a/tests/baselines/reference/commentsAfterCaseClauses1.types b/tests/baselines/reference/commentsAfterCaseClauses1.types
new file mode 100644
index 00000000000..c7759f1c2e6
--- /dev/null
+++ b/tests/baselines/reference/commentsAfterCaseClauses1.types
@@ -0,0 +1,37 @@
+=== tests/cases/compiler/commentsAfterCaseClauses1.ts ===
+function getSecurity(level) {
+>getSecurity : (level: any) => "Hi" | "hello" | "world"
+>level : any
+
+    switch(level){
+>level : any
+
+        case 0: // Zero
+>0 : 0
+
+        case 1: // one
+>1 : 1
+
+        case 2: // two
+>2 : 2
+
+            return "Hi";
+>"Hi" : "Hi"
+
+        case 3: // three
+>3 : 3
+
+        case 4   : // four
+>4 : 4
+
+            return "hello";
+>"hello" : "hello"
+
+        case 5: // five
+>5 : 5
+
+        default:  // default
+            return "world";
+>"world" : "world"
+    }
+}
diff --git a/tests/baselines/reference/commentsAfterCaseClauses2.js b/tests/baselines/reference/commentsAfterCaseClauses2.js
new file mode 100644
index 00000000000..44cd3c0da74
--- /dev/null
+++ b/tests/baselines/reference/commentsAfterCaseClauses2.js
@@ -0,0 +1,36 @@
+//// [commentsAfterCaseClauses2.ts]
+function getSecurity(level) {
+    switch(level){
+        case 0: // Zero
+        case 1: // one
+        case 2: // two
+            // Leading comments
+            return "Hi";
+        case 3: // three
+        case 4: // four
+            return "hello";
+        case 5: // five
+        default: // default
+            return "world";
+        // Comment After
+    } /*Comment 1*/ // Comment After 1
+    // Comment After 2
+}
+
+//// [commentsAfterCaseClauses2.js]
+function getSecurity(level) {
+    switch (level) {
+        case 0: // Zero
+        case 1: // one
+        case 2:// two
+            // Leading comments
+            return "Hi";
+        case 3: // three
+        case 4:// four
+            return "hello";
+        case 5: // five
+        default:// default
+            return "world";
+    } /*Comment 1*/ // Comment After 1
+    // Comment After 2
+}
diff --git a/tests/baselines/reference/commentsAfterCaseClauses2.symbols b/tests/baselines/reference/commentsAfterCaseClauses2.symbols
new file mode 100644
index 00000000000..b68cf18c1b9
--- /dev/null
+++ b/tests/baselines/reference/commentsAfterCaseClauses2.symbols
@@ -0,0 +1,23 @@
+=== tests/cases/compiler/commentsAfterCaseClauses2.ts ===
+function getSecurity(level) {
+>getSecurity : Symbol(getSecurity, Decl(commentsAfterCaseClauses2.ts, 0, 0))
+>level : Symbol(level, Decl(commentsAfterCaseClauses2.ts, 0, 21))
+
+    switch(level){
+>level : Symbol(level, Decl(commentsAfterCaseClauses2.ts, 0, 21))
+
+        case 0: // Zero
+        case 1: // one
+        case 2: // two
+            // Leading comments
+            return "Hi";
+        case 3: // three
+        case 4: // four
+            return "hello";
+        case 5: // five
+        default: // default
+            return "world";
+        // Comment After
+    } /*Comment 1*/ // Comment After 1
+    // Comment After 2
+}
diff --git a/tests/baselines/reference/commentsAfterCaseClauses2.types b/tests/baselines/reference/commentsAfterCaseClauses2.types
new file mode 100644
index 00000000000..3b2d2e7688a
--- /dev/null
+++ b/tests/baselines/reference/commentsAfterCaseClauses2.types
@@ -0,0 +1,41 @@
+=== tests/cases/compiler/commentsAfterCaseClauses2.ts ===
+function getSecurity(level) {
+>getSecurity : (level: any) => "Hi" | "hello" | "world"
+>level : any
+
+    switch(level){
+>level : any
+
+        case 0: // Zero
+>0 : 0
+
+        case 1: // one
+>1 : 1
+
+        case 2: // two
+>2 : 2
+
+            // Leading comments
+            return "Hi";
+>"Hi" : "Hi"
+
+        case 3: // three
+>3 : 3
+
+        case 4: // four
+>4 : 4
+
+            return "hello";
+>"hello" : "hello"
+
+        case 5: // five
+>5 : 5
+
+        default: // default
+            return "world";
+>"world" : "world"
+
+        // Comment After
+    } /*Comment 1*/ // Comment After 1
+    // Comment After 2
+}
diff --git a/tests/baselines/reference/commentsAfterCaseClauses3.js b/tests/baselines/reference/commentsAfterCaseClauses3.js
new file mode 100644
index 00000000000..9538ad06c4f
--- /dev/null
+++ b/tests/baselines/reference/commentsAfterCaseClauses3.js
@@ -0,0 +1,34 @@
+//// [commentsAfterCaseClauses3.ts]
+function getSecurity(level) {
+    switch(level){
+        case 0: /*Zero*/
+        case 1: /*One*/ 
+        case 2: /*two*/
+            // Leading comments
+            return "Hi";
+        case 3: /*three*/
+        case 4: /*four*/
+            return "hello";
+        case 5: /*five*/
+        default:  /*six*/
+            return "world";
+    }
+    
+}
+
+//// [commentsAfterCaseClauses3.js]
+function getSecurity(level) {
+    switch (level) {
+        case 0: /*Zero*/
+        case 1: /*One*/
+        case 2:/*two*/ 
+            // Leading comments
+            return "Hi";
+        case 3: /*three*/
+        case 4:/*four*/ 
+            return "hello";
+        case 5: /*five*/
+        default:/*six*/ 
+            return "world";
+    }
+}
diff --git a/tests/baselines/reference/commentsAfterCaseClauses3.symbols b/tests/baselines/reference/commentsAfterCaseClauses3.symbols
new file mode 100644
index 00000000000..73151cffdd8
--- /dev/null
+++ b/tests/baselines/reference/commentsAfterCaseClauses3.symbols
@@ -0,0 +1,22 @@
+=== tests/cases/compiler/commentsAfterCaseClauses3.ts ===
+function getSecurity(level) {
+>getSecurity : Symbol(getSecurity, Decl(commentsAfterCaseClauses3.ts, 0, 0))
+>level : Symbol(level, Decl(commentsAfterCaseClauses3.ts, 0, 21))
+
+    switch(level){
+>level : Symbol(level, Decl(commentsAfterCaseClauses3.ts, 0, 21))
+
+        case 0: /*Zero*/
+        case 1: /*One*/ 
+        case 2: /*two*/
+            // Leading comments
+            return "Hi";
+        case 3: /*three*/
+        case 4: /*four*/
+            return "hello";
+        case 5: /*five*/
+        default:  /*six*/
+            return "world";
+    }
+    
+}
diff --git a/tests/baselines/reference/commentsAfterCaseClauses3.types b/tests/baselines/reference/commentsAfterCaseClauses3.types
new file mode 100644
index 00000000000..556370f4395
--- /dev/null
+++ b/tests/baselines/reference/commentsAfterCaseClauses3.types
@@ -0,0 +1,39 @@
+=== tests/cases/compiler/commentsAfterCaseClauses3.ts ===
+function getSecurity(level) {
+>getSecurity : (level: any) => "Hi" | "hello" | "world"
+>level : any
+
+    switch(level){
+>level : any
+
+        case 0: /*Zero*/
+>0 : 0
+
+        case 1: /*One*/ 
+>1 : 1
+
+        case 2: /*two*/
+>2 : 2
+
+            // Leading comments
+            return "Hi";
+>"Hi" : "Hi"
+
+        case 3: /*three*/
+>3 : 3
+
+        case 4: /*four*/
+>4 : 4
+
+            return "hello";
+>"hello" : "hello"
+
+        case 5: /*five*/
+>5 : 5
+
+        default:  /*six*/
+            return "world";
+>"world" : "world"
+    }
+    
+}
diff --git a/tests/baselines/reference/parserRealSource1.js b/tests/baselines/reference/parserRealSource1.js
index d26e749a667..e41cb2a4b3f 100644
--- a/tests/baselines/reference/parserRealSource1.js
+++ b/tests/baselines/reference/parserRealSource1.js
@@ -247,28 +247,28 @@ var TypeScript;
         var addChar = function (index) {
             var ch = value.charCodeAt(index);
             switch (ch) {
-                case 0x09:
+                case 0x09:// tab
                     result += "\\t";
                     break;
-                case 0x0a:
+                case 0x0a:// line feed
                     result += "\\n";
                     break;
-                case 0x0b:
+                case 0x0b:// vertical tab
                     result += "\\v";
                     break;
-                case 0x0c:
+                case 0x0c:// form feed
                     result += "\\f";
                     break;
-                case 0x0d:
+                case 0x0d:// carriage return
                     result += "\\r";
                     break;
-                case 0x22:
+                case 0x22:// double quote
                     result += "\\\"";
                     break;
-                case 0x27:
+                case 0x27:// single quote
                     result += "\\\'";
                     break;
-                case 0x5c:
+                case 0x5c:// Backslash
                     result += "\\";
                     break;
                 default:
diff --git a/tests/baselines/reference/parserindenter.js b/tests/baselines/reference/parserindenter.js
index 8beb2393748..17f71318940 100644
--- a/tests/baselines/reference/parserindenter.js
+++ b/tests/baselines/reference/parserindenter.js
@@ -912,20 +912,20 @@ var Formatting;
         Indenter.prototype.GetSpecialCaseIndentation = function (token, node) {
             var indentationInfo = null;
             switch (token.Token) {
-                case AuthorTokenKind.atkLCurly:
+                case AuthorTokenKind.atkLCurly:// { is not part of the tree
                     indentationInfo = this.GetSpecialCaseIndentationForLCurly(node);
                     return indentationInfo;
                 case AuthorTokenKind.atkElse: // else is not part of the tree
-                case AuthorTokenKind.atkRBrack:
+                case AuthorTokenKind.atkRBrack:// ] is not part of the tree
                     indentationInfo = node.GetNodeStartLineIndentation(this);
                     return indentationInfo;
-                case AuthorTokenKind.atkRCurly:
+                case AuthorTokenKind.atkRCurly:// } is not part of the tree
                     // if '}' is for a body-block, get indentation based on its parent.
                     if (node.AuthorNode.Details.Kind == AuthorParseNodeKind.apnkBlock && node.AuthorNode.EdgeLabel == AuthorParseNodeEdge.apneBody)
                         node = node.Parent;
                     indentationInfo = node.GetNodeStartLineIndentation(this);
                     return indentationInfo;
-                case AuthorTokenKind.atkWhile:
+                case AuthorTokenKind.atkWhile:// while (in do-while) is not part of the tree
                     if (node.AuthorNode.Details.Kind == AuthorParseNodeKind.apnkDoWhile) {
                         indentationInfo = node.GetNodeStartLineIndentation(this);
                         return indentationInfo;
diff --git a/tests/baselines/reference/switchStatementsWithMultipleDefaults.js b/tests/baselines/reference/switchStatementsWithMultipleDefaults.js
index e65e10a0c99..e41d8c016ef 100644
--- a/tests/baselines/reference/switchStatementsWithMultipleDefaults.js
+++ b/tests/baselines/reference/switchStatementsWithMultipleDefaults.js
@@ -35,7 +35,7 @@ var x = 10;
 switch (x) {
     case 1:
     case 2:
-    default:
+    default:// No issues.
         break;
     default: // Error; second 'default' clause.
     default: // Error; third 'default' clause.
@@ -43,12 +43,12 @@ switch (x) {
         x *= x;
 }
 switch (x) {
-    default:
+    default:// No issues.
         break;
     case 100:
         switch (x * x) {
             default: // No issues.
-            default:
+            default:// Error; second 'default' clause.
                 break;
             case 10000:
                 x /= x;
diff --git a/tests/baselines/reference/switchStatementsWithMultipleDefaults1.js b/tests/baselines/reference/switchStatementsWithMultipleDefaults1.js
index 2d52dd761cc..d733ce38a7b 100644
--- a/tests/baselines/reference/switchStatementsWithMultipleDefaults1.js
+++ b/tests/baselines/reference/switchStatementsWithMultipleDefaults1.js
@@ -17,7 +17,7 @@ var x = 10;
 switch (x) {
     case 1:
     case 2:
-    default:
+    default:// No issues.
         break;
     default: // Error; second 'default' clause.
     default: // Error; third 'default' clause.
diff --git a/tests/cases/compiler/commentsAfterCaseClauses1.ts b/tests/cases/compiler/commentsAfterCaseClauses1.ts
new file mode 100644
index 00000000000..8b494161584
--- /dev/null
+++ b/tests/cases/compiler/commentsAfterCaseClauses1.ts
@@ -0,0 +1,14 @@
+function getSecurity(level) {
+    switch(level){
+        case 0: // Zero
+        case 1: // one
+        case 2: // two
+            return "Hi";
+        case 3: // three
+        case 4   : // four
+            return "hello";
+        case 5: // five
+        default:  // default
+            return "world";
+    }
+}
\ No newline at end of file
diff --git a/tests/cases/compiler/commentsAfterCaseClauses2.ts b/tests/cases/compiler/commentsAfterCaseClauses2.ts
new file mode 100644
index 00000000000..9c35b80894e
--- /dev/null
+++ b/tests/cases/compiler/commentsAfterCaseClauses2.ts
@@ -0,0 +1,17 @@
+function getSecurity(level) {
+    switch(level){
+        case 0: // Zero
+        case 1: // one
+        case 2: // two
+            // Leading comments
+            return "Hi";
+        case 3: // three
+        case 4: // four
+            return "hello";
+        case 5: // five
+        default: // default
+            return "world";
+        // Comment After
+    } /*Comment 1*/ // Comment After 1
+    // Comment After 2
+}
\ No newline at end of file
diff --git a/tests/cases/compiler/commentsAfterCaseClauses3.ts b/tests/cases/compiler/commentsAfterCaseClauses3.ts
new file mode 100644
index 00000000000..894e743c2e7
--- /dev/null
+++ b/tests/cases/compiler/commentsAfterCaseClauses3.ts
@@ -0,0 +1,16 @@
+function getSecurity(level) {
+    switch(level){
+        case 0: /*Zero*/
+        case 1: /*One*/ 
+        case 2: /*two*/
+            // Leading comments
+            return "Hi";
+        case 3: /*three*/
+        case 4: /*four*/
+            return "hello";
+        case 5: /*five*/
+        default:  /*six*/
+            return "world";
+    }
+    
+}
\ No newline at end of file

From 1c3cdf11b52564d7ee507e12a43588f2a279a1ca Mon Sep 17 00:00:00 2001
From: Yui <yuit@users.noreply.github.com>
Date: Tue, 23 May 2017 10:26:07 -0700
Subject: [PATCH 09/56] Fix the issue 15232 (#16004)

---
 src/compiler/comments.ts                      |  6 +-
 .../commentEmittingInPreserveJsx1.js          | 57 +++++++++++++++++++
 .../commentEmittingInPreserveJsx1.symbols     | 45 +++++++++++++++
 .../commentEmittingInPreserveJsx1.types       | 51 +++++++++++++++++
 .../jsx/commentEmittingInPreserveJsx1.tsx     | 35 ++++++++++++
 5 files changed, 192 insertions(+), 2 deletions(-)
 create mode 100644 tests/baselines/reference/commentEmittingInPreserveJsx1.js
 create mode 100644 tests/baselines/reference/commentEmittingInPreserveJsx1.symbols
 create mode 100644 tests/baselines/reference/commentEmittingInPreserveJsx1.types
 create mode 100644 tests/cases/conformance/jsx/commentEmittingInPreserveJsx1.tsx

diff --git a/src/compiler/comments.ts b/src/compiler/comments.ts
index c50cacc2ccb..06285309f64 100644
--- a/src/compiler/comments.ts
+++ b/src/compiler/comments.ts
@@ -58,8 +58,10 @@ namespace ts {
                     }
 
                     const isEmittedNode = node.kind !== SyntaxKind.NotEmittedStatement;
-                    const skipLeadingComments = pos < 0 || (emitFlags & EmitFlags.NoLeadingComments) !== 0;
-                    const skipTrailingComments = end < 0 || (emitFlags & EmitFlags.NoTrailingComments) !== 0;
+                    // We have to explicitly check that the node is JsxText because if the compilerOptions.jsx is "preserve" we will not do any transformation.
+                    // It is expensive to walk entire tree just to set one kind of node to have no comments.
+                    const skipLeadingComments = pos < 0 || (emitFlags & EmitFlags.NoLeadingComments) !== 0 || node.kind === SyntaxKind.JsxText;
+                    const skipTrailingComments = end < 0 || (emitFlags & EmitFlags.NoTrailingComments) !== 0 || node.kind === SyntaxKind.JsxText;
 
                     // Emit leading comments if the position is not synthesized and the node
                     // has not opted out from emitting leading comments.
diff --git a/tests/baselines/reference/commentEmittingInPreserveJsx1.js b/tests/baselines/reference/commentEmittingInPreserveJsx1.js
new file mode 100644
index 00000000000..45e2148e007
--- /dev/null
+++ b/tests/baselines/reference/commentEmittingInPreserveJsx1.js
@@ -0,0 +1,57 @@
+//// [file.tsx]
+import React = require('react');
+
+<div>
+    // Not Comment
+</div>;
+
+<div>
+    // Not Comment
+    {
+        //Comment just Fine
+    }
+    // Another not Comment
+</div>;
+
+<div>
+    // Not Comment
+    {
+        //Comment just Fine
+        "Hi"
+    }
+    // Another not Comment
+</div>;
+
+<div>
+    /* Not Comment */
+    {
+        //Comment just Fine
+        "Hi"
+    }
+</div>;
+
+//// [file.jsx]
+"use strict";
+exports.__esModule = true;
+var React = require("react");
+<div>
+    // Not Comment
+</div>;
+<div>
+    // Not Comment
+    
+    // Another not Comment
+</div>;
+<div>
+    // Not Comment
+    {
+//Comment just Fine
+"Hi"}
+    // Another not Comment
+</div>;
+<div>
+    /* Not Comment */
+    {
+//Comment just Fine
+"Hi"}
+</div>;
diff --git a/tests/baselines/reference/commentEmittingInPreserveJsx1.symbols b/tests/baselines/reference/commentEmittingInPreserveJsx1.symbols
new file mode 100644
index 00000000000..43d833e27b1
--- /dev/null
+++ b/tests/baselines/reference/commentEmittingInPreserveJsx1.symbols
@@ -0,0 +1,45 @@
+=== tests/cases/conformance/jsx/file.tsx ===
+import React = require('react');
+>React : Symbol(React, Decl(file.tsx, 0, 0))
+
+<div>
+>div : Symbol(JSX.IntrinsicElements.div, Decl(react.d.ts, 2399, 45))
+
+    // Not Comment
+</div>;
+>div : Symbol(JSX.IntrinsicElements.div, Decl(react.d.ts, 2399, 45))
+
+<div>
+>div : Symbol(JSX.IntrinsicElements.div, Decl(react.d.ts, 2399, 45))
+
+    // Not Comment
+    {
+        //Comment just Fine
+    }
+    // Another not Comment
+</div>;
+>div : Symbol(JSX.IntrinsicElements.div, Decl(react.d.ts, 2399, 45))
+
+<div>
+>div : Symbol(JSX.IntrinsicElements.div, Decl(react.d.ts, 2399, 45))
+
+    // Not Comment
+    {
+        //Comment just Fine
+        "Hi"
+    }
+    // Another not Comment
+</div>;
+>div : Symbol(JSX.IntrinsicElements.div, Decl(react.d.ts, 2399, 45))
+
+<div>
+>div : Symbol(JSX.IntrinsicElements.div, Decl(react.d.ts, 2399, 45))
+
+    /* Not Comment */
+    {
+        //Comment just Fine
+        "Hi"
+    }
+</div>;
+>div : Symbol(JSX.IntrinsicElements.div, Decl(react.d.ts, 2399, 45))
+
diff --git a/tests/baselines/reference/commentEmittingInPreserveJsx1.types b/tests/baselines/reference/commentEmittingInPreserveJsx1.types
new file mode 100644
index 00000000000..2e968033d4c
--- /dev/null
+++ b/tests/baselines/reference/commentEmittingInPreserveJsx1.types
@@ -0,0 +1,51 @@
+=== tests/cases/conformance/jsx/file.tsx ===
+import React = require('react');
+>React : typeof React
+
+<div>
+><div>    // Not Comment</div> : JSX.Element
+>div : any
+
+    // Not Comment
+</div>;
+>div : any
+
+<div>
+><div>    // Not Comment    {        //Comment just Fine    }    // Another not Comment</div> : JSX.Element
+>div : any
+
+    // Not Comment
+    {
+        //Comment just Fine
+    }
+    // Another not Comment
+</div>;
+>div : any
+
+<div>
+><div>    // Not Comment    {        //Comment just Fine        "Hi"    }    // Another not Comment</div> : JSX.Element
+>div : any
+
+    // Not Comment
+    {
+        //Comment just Fine
+        "Hi"
+>"Hi" : "Hi"
+    }
+    // Another not Comment
+</div>;
+>div : any
+
+<div>
+><div>    /* Not Comment */    {        //Comment just Fine        "Hi"    }</div> : JSX.Element
+>div : any
+
+    /* Not Comment */
+    {
+        //Comment just Fine
+        "Hi"
+>"Hi" : "Hi"
+    }
+</div>;
+>div : any
+
diff --git a/tests/cases/conformance/jsx/commentEmittingInPreserveJsx1.tsx b/tests/cases/conformance/jsx/commentEmittingInPreserveJsx1.tsx
new file mode 100644
index 00000000000..323cd029189
--- /dev/null
+++ b/tests/cases/conformance/jsx/commentEmittingInPreserveJsx1.tsx
@@ -0,0 +1,35 @@
+// @filename: file.tsx
+// @jsx: preserve
+// @noLib: true
+// @libFiles: react.d.ts,lib.d.ts
+
+import React = require('react');
+
+<div>
+    // Not Comment
+</div>;
+
+<div>
+    // Not Comment
+    {
+        //Comment just Fine
+    }
+    // Another not Comment
+</div>;
+
+<div>
+    // Not Comment
+    {
+        //Comment just Fine
+        "Hi"
+    }
+    // Another not Comment
+</div>;
+
+<div>
+    /* Not Comment */
+    {
+        //Comment just Fine
+        "Hi"
+    }
+</div>;
\ No newline at end of file

From 49638ab2eb2c9674b52660ab46009249e2f3a7dc Mon Sep 17 00:00:00 2001
From: Ika <ikatyang@gmail.com>
Date: Wed, 24 May 2017 01:37:21 +0800
Subject: [PATCH 10/56] Add missing questionToken in
 emitMethod/PropertyDeclaration (#16020)

---
 src/compiler/emitter.ts                       |  2 ++
 src/harness/unittests/printer.ts              | 32 +++++++++++++++++++
 ...ctly.classWithOptionalMethodAndProperty.js |  4 +++
 3 files changed, 38 insertions(+)
 create mode 100644 tests/baselines/reference/printerApi/printsNodeCorrectly.classWithOptionalMethodAndProperty.js

diff --git a/src/compiler/emitter.ts b/src/compiler/emitter.ts
index c0b0d170de8..0cbb961e9f7 100644
--- a/src/compiler/emitter.ts
+++ b/src/compiler/emitter.ts
@@ -860,6 +860,7 @@ namespace ts {
             emitDecorators(node, node.decorators);
             emitModifiers(node, node.modifiers);
             emit(node.name);
+            writeIfPresent(node.questionToken, "?");
             emitWithPrefix(": ", node.type);
             emitExpressionWithPrefix(" = ", node.initializer);
             write(";");
@@ -881,6 +882,7 @@ namespace ts {
             emitModifiers(node, node.modifiers);
             writeIfPresent(node.asteriskToken, "*");
             emit(node.name);
+            writeIfPresent(node.questionToken, "?");
             emitSignatureAndBody(node, emitSignatureHead);
         }
 
diff --git a/src/harness/unittests/printer.ts b/src/harness/unittests/printer.ts
index 0c6d4bfe8f7..aedaacbf76c 100644
--- a/src/harness/unittests/printer.ts
+++ b/src/harness/unittests/printer.ts
@@ -98,8 +98,40 @@ namespace ts {
                     )
                 ])
             );
+
+            // https://github.com/Microsoft/TypeScript/issues/15971
+            const classWithOptionalMethodAndProperty = createClassDeclaration(
+                undefined,
+                /* modifiers */ createNodeArray([createToken(SyntaxKind.DeclareKeyword)]),
+                /* name      */ createIdentifier("X"),
+                undefined,
+                undefined,
+                createNodeArray([
+                    createMethod(
+                        undefined,
+                        undefined,
+                        undefined,
+                        /* name          */ createIdentifier("method"),
+                        /* questionToken */ createToken(SyntaxKind.QuestionToken),
+                        undefined,
+                        undefined,
+                        /* type          */ createKeywordTypeNode(SyntaxKind.VoidKeyword),
+                        undefined
+                    ),
+                    createProperty(
+                        undefined,
+                        undefined,
+                        /* name          */ createIdentifier("property"),
+                        /* questionToken */ createToken(SyntaxKind.QuestionToken),
+                        /* type          */ createKeywordTypeNode(SyntaxKind.StringKeyword),
+                        undefined
+                    ),
+                ])
+            );
+
             // tslint:enable boolean-trivia
             printsCorrectly("class", {}, printer => printer.printNode(EmitHint.Unspecified, syntheticNode, sourceFile));
+            printsCorrectly("classWithOptionalMethodAndProperty", {}, printer => printer.printNode(EmitHint.Unspecified, classWithOptionalMethodAndProperty, sourceFile));
         });
     });
 }
diff --git a/tests/baselines/reference/printerApi/printsNodeCorrectly.classWithOptionalMethodAndProperty.js b/tests/baselines/reference/printerApi/printsNodeCorrectly.classWithOptionalMethodAndProperty.js
new file mode 100644
index 00000000000..6626f2e35c9
--- /dev/null
+++ b/tests/baselines/reference/printerApi/printsNodeCorrectly.classWithOptionalMethodAndProperty.js
@@ -0,0 +1,4 @@
+declare class X {
+    method?(): void;
+    property?: string;
+}
\ No newline at end of file

From e4d6752a932c680d67bf3982393a3276819d9cd7 Mon Sep 17 00:00:00 2001
From: Donald Pipowitch <pipo@senaeh.de>
Date: Tue, 23 May 2017 19:40:46 +0200
Subject: [PATCH 11/56] add `createProgram` docs (#15697)

* add `createProgram` docs

* updated `createProgram` docs
---
 src/compiler/program.ts | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/src/compiler/program.ts b/src/compiler/program.ts
index dae49832183..dd293727b4a 100644
--- a/src/compiler/program.ts
+++ b/src/compiler/program.ts
@@ -386,6 +386,19 @@ namespace ts {
         allDiagnostics?: Diagnostic[];
     }
 
+    /**
+     * Create a new 'Program' instance. A Program is an immutable collection of 'SourceFile's and a 'CompilerOptions'
+     * that represent a compilation unit.
+     *
+     * Creating a program proceeds from a set of root files, expanding the set of inputs by following imports and
+     * triple-slash-reference-path directives transitively. '@types' and triple-slash-reference-types are also pulled in.
+     *
+     * @param rootNames - A set of root files.
+     * @param options - The compiler options which should be used.
+     * @param host - The host interacts with the underlying file system.
+     * @param oldProgram - Reuses an old program structure.
+     * @returns A 'Program' object.
+     */
     export function createProgram(rootNames: string[], options: CompilerOptions, host?: CompilerHost, oldProgram?: Program): Program {
         let program: Program;
         let files: SourceFile[] = [];

From f9a1fca38810823654315f0a90c969e76b6d7bfc Mon Sep 17 00:00:00 2001
From: Ika <ikatyang@gmail.com>
Date: Wed, 24 May 2017 02:07:34 +0800
Subject: [PATCH 12/56] Add missing emitter for NamespaceExportDeclaration
 (#16025)

---
 src/compiler/binder.ts                                    | 1 +
 src/compiler/emitter.ts                                   | 8 ++++++++
 src/compiler/transformers/ts.ts                           | 3 +++
 src/harness/unittests/printer.ts                          | 3 +++
 .../printsNodeCorrectly.namespaceExportDeclaration.js     | 1 +
 5 files changed, 16 insertions(+)
 create mode 100644 tests/baselines/reference/printerApi/printsNodeCorrectly.namespaceExportDeclaration.js

diff --git a/src/compiler/binder.ts b/src/compiler/binder.ts
index 30e2b7781f6..204a979d928 100644
--- a/src/compiler/binder.ts
+++ b/src/compiler/binder.ts
@@ -3398,6 +3398,7 @@ namespace ts {
             case SyntaxKind.IndexedAccessType:
             case SyntaxKind.MappedType:
             case SyntaxKind.LiteralType:
+            case SyntaxKind.NamespaceExportDeclaration:
                 // Types and signatures are TypeScript syntax, and exclude all other facts.
                 transformFlags = TransformFlags.AssertTypeScript;
                 excludeFlags = TransformFlags.TypeExcludes;
diff --git a/src/compiler/emitter.ts b/src/compiler/emitter.ts
index 0cbb961e9f7..e00d46fe94e 100644
--- a/src/compiler/emitter.ts
+++ b/src/compiler/emitter.ts
@@ -571,6 +571,8 @@ namespace ts {
                     return emitModuleBlock(<ModuleBlock>node);
                 case SyntaxKind.CaseBlock:
                     return emitCaseBlock(<CaseBlock>node);
+                case SyntaxKind.NamespaceExportDeclaration:
+                    return emitNamespaceExportDeclaration(<NamespaceExportDeclaration>node);
                 case SyntaxKind.ImportEqualsDeclaration:
                     return emitImportEqualsDeclaration(<ImportEqualsDeclaration>node);
                 case SyntaxKind.ImportDeclaration:
@@ -1886,6 +1888,12 @@ namespace ts {
             write(";");
         }
 
+        function emitNamespaceExportDeclaration(node: NamespaceExportDeclaration) {
+            write("export as namespace ");
+            emit(node.name);
+            write(";");
+        }
+
         function emitNamedExports(node: NamedExports) {
             emitNamedImportsOrExports(node);
         }
diff --git a/src/compiler/transformers/ts.ts b/src/compiler/transformers/ts.ts
index cc7f89acfb8..d02aaecf333 100644
--- a/src/compiler/transformers/ts.ts
+++ b/src/compiler/transformers/ts.ts
@@ -345,6 +345,9 @@ namespace ts {
 
                 case SyntaxKind.PropertyDeclaration:
                     // TypeScript property declarations are elided.
+
+                case SyntaxKind.NamespaceExportDeclaration:
+                    // TypeScript namespace export declarations are elided.
                     return undefined;
 
                 case SyntaxKind.Constructor:
diff --git a/src/harness/unittests/printer.ts b/src/harness/unittests/printer.ts
index aedaacbf76c..a9af46b2780 100644
--- a/src/harness/unittests/printer.ts
+++ b/src/harness/unittests/printer.ts
@@ -131,6 +131,9 @@ namespace ts {
 
             // tslint:enable boolean-trivia
             printsCorrectly("class", {}, printer => printer.printNode(EmitHint.Unspecified, syntheticNode, sourceFile));
+
+            printsCorrectly("namespaceExportDeclaration", {}, printer => printer.printNode(EmitHint.Unspecified, createNamespaceExportDeclaration("B"), sourceFile));
+
             printsCorrectly("classWithOptionalMethodAndProperty", {}, printer => printer.printNode(EmitHint.Unspecified, classWithOptionalMethodAndProperty, sourceFile));
         });
     });
diff --git a/tests/baselines/reference/printerApi/printsNodeCorrectly.namespaceExportDeclaration.js b/tests/baselines/reference/printerApi/printsNodeCorrectly.namespaceExportDeclaration.js
new file mode 100644
index 00000000000..725da0cef9f
--- /dev/null
+++ b/tests/baselines/reference/printerApi/printsNodeCorrectly.namespaceExportDeclaration.js
@@ -0,0 +1 @@
+export as namespace B;
\ No newline at end of file

From 5ef6192c20c051d3b03bc0059b7a1e0a86163379 Mon Sep 17 00:00:00 2001
From: Mohamed Hegazy <mhegazy@microsoft.com>
Date: Tue, 23 May 2017 13:40:03 -0700
Subject: [PATCH 13/56] Allow export default interface. Related to issue 3792.
 (#16040)

* Allow export default interface. Related to issue 3792.

* Update exportDefaultAbstractClass test

* Allow default export to be a non-value for lookup purposes

* Add local usage to exportDefaultInterface test
---
 src/compiler/parser.ts                        |  7 +--
 src/compiler/utilities.ts                     |  4 +-
 .../reference/exportDefaultAbstractClass.js   | 48 +++++++++++++++++--
 .../exportDefaultAbstractClass.symbols        | 27 ++++++++++-
 .../exportDefaultAbstractClass.types          | 31 +++++++++++-
 .../reference/exportDefaultInterface.js       | 24 ++++++++++
 .../reference/exportDefaultInterface.symbols  | 31 ++++++++++++
 .../reference/exportDefaultInterface.types    | 33 +++++++++++++
 .../compiler/exportDefaultAbstractClass.ts    | 16 +++++--
 .../cases/compiler/exportDefaultInterface.ts  | 11 +++++
 10 files changed, 215 insertions(+), 17 deletions(-)
 create mode 100644 tests/baselines/reference/exportDefaultInterface.js
 create mode 100644 tests/baselines/reference/exportDefaultInterface.symbols
 create mode 100644 tests/baselines/reference/exportDefaultInterface.types
 create mode 100644 tests/cases/compiler/exportDefaultInterface.ts

diff --git a/src/compiler/parser.ts b/src/compiler/parser.ts
index 87bd36ee3a0..04209ab0924 100644
--- a/src/compiler/parser.ts
+++ b/src/compiler/parser.ts
@@ -1240,12 +1240,12 @@ namespace ts {
             if (token() === SyntaxKind.ExportKeyword) {
                 nextToken();
                 if (token() === SyntaxKind.DefaultKeyword) {
-                    return lookAhead(nextTokenIsClassOrFunctionOrAsync);
+                    return lookAhead(nextTokenCanFollowDefaultKeyword);
                 }
                 return token() !== SyntaxKind.AsteriskToken && token() !== SyntaxKind.AsKeyword && token() !== SyntaxKind.OpenBraceToken && canFollowModifier();
             }
             if (token() === SyntaxKind.DefaultKeyword) {
-                return nextTokenIsClassOrFunctionOrAsync();
+                return nextTokenCanFollowDefaultKeyword();
             }
             if (token() === SyntaxKind.StaticKeyword) {
                 nextToken();
@@ -1267,9 +1267,10 @@ namespace ts {
                 || isLiteralPropertyName();
         }
 
-        function nextTokenIsClassOrFunctionOrAsync(): boolean {
+        function nextTokenCanFollowDefaultKeyword(): boolean {
             nextToken();
             return token() === SyntaxKind.ClassKeyword || token() === SyntaxKind.FunctionKeyword ||
+                token() === SyntaxKind.InterfaceKeyword ||
                 (token() === SyntaxKind.AbstractKeyword && lookAhead(nextTokenIsClassKeywordOnSameLine)) ||
                 (token() === SyntaxKind.AsyncKeyword && lookAhead(nextTokenIsFunctionKeywordOnSameLine));
         }
diff --git a/src/compiler/utilities.ts b/src/compiler/utilities.ts
index 3a8b8b59f7d..22210419af7 100644
--- a/src/compiler/utilities.ts
+++ b/src/compiler/utilities.ts
@@ -3168,11 +3168,11 @@ namespace ts {
     }
 
     export function getLocalSymbolForExportDefault(symbol: Symbol) {
-        return isExportDefaultSymbol(symbol) ? symbol.valueDeclaration.localSymbol : undefined;
+        return isExportDefaultSymbol(symbol) ? symbol.declarations[0].localSymbol : undefined;
     }
 
     function isExportDefaultSymbol(symbol: Symbol): boolean {
-        return symbol && symbol.valueDeclaration && hasModifier(symbol.valueDeclaration, ModifierFlags.Default);
+        return symbol && length(symbol.declarations) > 0 && hasModifier(symbol.declarations[0], ModifierFlags.Default);
     }
 
     /** Return ".ts", ".d.ts", or ".tsx", if that is the extension. */
diff --git a/tests/baselines/reference/exportDefaultAbstractClass.js b/tests/baselines/reference/exportDefaultAbstractClass.js
index c8dba03543d..38976311d63 100644
--- a/tests/baselines/reference/exportDefaultAbstractClass.js
+++ b/tests/baselines/reference/exportDefaultAbstractClass.js
@@ -1,14 +1,29 @@
 //// [tests/cases/compiler/exportDefaultAbstractClass.ts] ////
 
 //// [a.ts]
-export default abstract class A {}
+export default abstract class A { a: number; }
+
+class B extends A {}
+new B().a.toExponential();
 
 //// [b.ts]
-import A from './a'
-
+import A from './a';
+
+class C extends A {}
+new C().a.toExponential();
 
 //// [a.js]
 "use strict";
+var __extends = (this && this.__extends) || (function () {
+    var extendStatics = Object.setPrototypeOf ||
+        ({ __proto__: [] } instanceof Array && function (d, b) { d.__proto__ = b; }) ||
+        function (d, b) { for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p]; };
+    return function (d, b) {
+        extendStatics(d, b);
+        function __() { this.constructor = d; }
+        d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
+    };
+})();
 exports.__esModule = true;
 var A = (function () {
     function A() {
@@ -16,6 +31,33 @@ var A = (function () {
     return A;
 }());
 exports["default"] = A;
+var B = (function (_super) {
+    __extends(B, _super);
+    function B() {
+        return _super !== null && _super.apply(this, arguments) || this;
+    }
+    return B;
+}(A));
+new B().a.toExponential();
 //// [b.js]
 "use strict";
+var __extends = (this && this.__extends) || (function () {
+    var extendStatics = Object.setPrototypeOf ||
+        ({ __proto__: [] } instanceof Array && function (d, b) { d.__proto__ = b; }) ||
+        function (d, b) { for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p]; };
+    return function (d, b) {
+        extendStatics(d, b);
+        function __() { this.constructor = d; }
+        d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
+    };
+})();
 exports.__esModule = true;
+var a_1 = require("./a");
+var C = (function (_super) {
+    __extends(C, _super);
+    function C() {
+        return _super !== null && _super.apply(this, arguments) || this;
+    }
+    return C;
+}(a_1["default"]));
+new C().a.toExponential();
diff --git a/tests/baselines/reference/exportDefaultAbstractClass.symbols b/tests/baselines/reference/exportDefaultAbstractClass.symbols
index 75c6c068f08..27e42487f31 100644
--- a/tests/baselines/reference/exportDefaultAbstractClass.symbols
+++ b/tests/baselines/reference/exportDefaultAbstractClass.symbols
@@ -1,8 +1,31 @@
 === tests/cases/compiler/a.ts ===
-export default abstract class A {}
+export default abstract class A { a: number; }
+>A : Symbol(A, Decl(a.ts, 0, 0))
+>a : Symbol(A.a, Decl(a.ts, 0, 33))
+
+class B extends A {}
+>B : Symbol(B, Decl(a.ts, 0, 46))
 >A : Symbol(A, Decl(a.ts, 0, 0))
 
+new B().a.toExponential();
+>new B().a.toExponential : Symbol(Number.toExponential, Decl(lib.d.ts, --, --))
+>new B().a : Symbol(A.a, Decl(a.ts, 0, 33))
+>B : Symbol(B, Decl(a.ts, 0, 46))
+>a : Symbol(A.a, Decl(a.ts, 0, 33))
+>toExponential : Symbol(Number.toExponential, Decl(lib.d.ts, --, --))
+
 === tests/cases/compiler/b.ts ===
-import A from './a'
+import A from './a';
 >A : Symbol(A, Decl(b.ts, 0, 6))
 
+class C extends A {}
+>C : Symbol(C, Decl(b.ts, 0, 20))
+>A : Symbol(A, Decl(b.ts, 0, 6))
+
+new C().a.toExponential();
+>new C().a.toExponential : Symbol(Number.toExponential, Decl(lib.d.ts, --, --))
+>new C().a : Symbol(A.a, Decl(a.ts, 0, 33))
+>C : Symbol(C, Decl(b.ts, 0, 20))
+>a : Symbol(A.a, Decl(a.ts, 0, 33))
+>toExponential : Symbol(Number.toExponential, Decl(lib.d.ts, --, --))
+
diff --git a/tests/baselines/reference/exportDefaultAbstractClass.types b/tests/baselines/reference/exportDefaultAbstractClass.types
index d400be1af43..776ad01420a 100644
--- a/tests/baselines/reference/exportDefaultAbstractClass.types
+++ b/tests/baselines/reference/exportDefaultAbstractClass.types
@@ -1,8 +1,35 @@
 === tests/cases/compiler/a.ts ===
-export default abstract class A {}
+export default abstract class A { a: number; }
+>A : A
+>a : number
+
+class B extends A {}
+>B : B
 >A : A
 
+new B().a.toExponential();
+>new B().a.toExponential() : string
+>new B().a.toExponential : (fractionDigits?: number) => string
+>new B().a : number
+>new B() : B
+>B : typeof B
+>a : number
+>toExponential : (fractionDigits?: number) => string
+
 === tests/cases/compiler/b.ts ===
-import A from './a'
+import A from './a';
 >A : typeof A
 
+class C extends A {}
+>C : C
+>A : A
+
+new C().a.toExponential();
+>new C().a.toExponential() : string
+>new C().a.toExponential : (fractionDigits?: number) => string
+>new C().a : number
+>new C() : C
+>C : typeof C
+>a : number
+>toExponential : (fractionDigits?: number) => string
+
diff --git a/tests/baselines/reference/exportDefaultInterface.js b/tests/baselines/reference/exportDefaultInterface.js
new file mode 100644
index 00000000000..e7b5c945e32
--- /dev/null
+++ b/tests/baselines/reference/exportDefaultInterface.js
@@ -0,0 +1,24 @@
+//// [tests/cases/compiler/exportDefaultInterface.ts] ////
+
+//// [a.ts]
+export default interface A { value: number; }
+
+var a: A;
+a.value.toExponential();
+
+//// [b.ts]
+import A from './a';
+
+var a: A;
+a.value.toExponential();
+
+//// [a.js]
+"use strict";
+exports.__esModule = true;
+var a;
+a.value.toExponential();
+//// [b.js]
+"use strict";
+exports.__esModule = true;
+var a;
+a.value.toExponential();
diff --git a/tests/baselines/reference/exportDefaultInterface.symbols b/tests/baselines/reference/exportDefaultInterface.symbols
new file mode 100644
index 00000000000..1a3b172fe97
--- /dev/null
+++ b/tests/baselines/reference/exportDefaultInterface.symbols
@@ -0,0 +1,31 @@
+=== tests/cases/compiler/a.ts ===
+export default interface A { value: number; }
+>A : Symbol(A, Decl(a.ts, 0, 0))
+>value : Symbol(A.value, Decl(a.ts, 0, 28))
+
+var a: A;
+>a : Symbol(a, Decl(a.ts, 2, 3))
+>A : Symbol(A, Decl(a.ts, 0, 0))
+
+a.value.toExponential();
+>a.value.toExponential : Symbol(Number.toExponential, Decl(lib.d.ts, --, --))
+>a.value : Symbol(A.value, Decl(a.ts, 0, 28))
+>a : Symbol(a, Decl(a.ts, 2, 3))
+>value : Symbol(A.value, Decl(a.ts, 0, 28))
+>toExponential : Symbol(Number.toExponential, Decl(lib.d.ts, --, --))
+
+=== tests/cases/compiler/b.ts ===
+import A from './a';
+>A : Symbol(A, Decl(b.ts, 0, 6))
+
+var a: A;
+>a : Symbol(a, Decl(b.ts, 2, 3))
+>A : Symbol(A, Decl(b.ts, 0, 6))
+
+a.value.toExponential();
+>a.value.toExponential : Symbol(Number.toExponential, Decl(lib.d.ts, --, --))
+>a.value : Symbol(A.value, Decl(a.ts, 0, 28))
+>a : Symbol(a, Decl(b.ts, 2, 3))
+>value : Symbol(A.value, Decl(a.ts, 0, 28))
+>toExponential : Symbol(Number.toExponential, Decl(lib.d.ts, --, --))
+
diff --git a/tests/baselines/reference/exportDefaultInterface.types b/tests/baselines/reference/exportDefaultInterface.types
new file mode 100644
index 00000000000..636197339f4
--- /dev/null
+++ b/tests/baselines/reference/exportDefaultInterface.types
@@ -0,0 +1,33 @@
+=== tests/cases/compiler/a.ts ===
+export default interface A { value: number; }
+>A : A
+>value : number
+
+var a: A;
+>a : A
+>A : A
+
+a.value.toExponential();
+>a.value.toExponential() : string
+>a.value.toExponential : (fractionDigits?: number) => string
+>a.value : number
+>a : A
+>value : number
+>toExponential : (fractionDigits?: number) => string
+
+=== tests/cases/compiler/b.ts ===
+import A from './a';
+>A : any
+
+var a: A;
+>a : A
+>A : A
+
+a.value.toExponential();
+>a.value.toExponential() : string
+>a.value.toExponential : (fractionDigits?: number) => string
+>a.value : number
+>a : A
+>value : number
+>toExponential : (fractionDigits?: number) => string
+
diff --git a/tests/cases/compiler/exportDefaultAbstractClass.ts b/tests/cases/compiler/exportDefaultAbstractClass.ts
index 584e95b6b03..31877911622 100644
--- a/tests/cases/compiler/exportDefaultAbstractClass.ts
+++ b/tests/cases/compiler/exportDefaultAbstractClass.ts
@@ -1,5 +1,11 @@
-// @filename: a.ts
-export default abstract class A {}
-
-// @filename: b.ts
-import A from './a'
+// @Filename: a.ts
+export default abstract class A { a: number; }
+
+class B extends A {}
+new B().a.toExponential();
+
+// @Filename: b.ts
+import A from './a';
+
+class C extends A {}
+new C().a.toExponential();
\ No newline at end of file
diff --git a/tests/cases/compiler/exportDefaultInterface.ts b/tests/cases/compiler/exportDefaultInterface.ts
new file mode 100644
index 00000000000..c7bbbe8019e
--- /dev/null
+++ b/tests/cases/compiler/exportDefaultInterface.ts
@@ -0,0 +1,11 @@
+// @Filename: a.ts
+export default interface A { value: number; }
+
+var a: A;
+a.value.toExponential();
+
+// @Filename: b.ts
+import A from './a';
+
+var a: A;
+a.value.toExponential();
\ No newline at end of file

From 2f65b2c160c3abe13271682d8b1bff525de93438 Mon Sep 17 00:00:00 2001
From: Herrington Darkholme <HerringtonDarkholme@users.noreply.github.com>
Date: Wed, 24 May 2017 05:13:32 +0800
Subject: [PATCH 14/56] fix #11463, null assertion block uninitialized error
 (#14020)

---
 src/compiler/checker.ts                            |  1 +
 .../baselines/reference/typeGuardsAsAssertions.js  |  9 +++++++++
 .../reference/typeGuardsAsAssertions.symbols       | 12 ++++++++++++
 .../reference/typeGuardsAsAssertions.types         | 14 ++++++++++++++
 .../controlFlow/typeGuardsAsAssertions.ts          |  5 +++++
 5 files changed, 41 insertions(+)

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 07c20ad7aa0..ce982a113f2 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -12035,6 +12035,7 @@ namespace ts {
             // declaration container are the same).
             const assumeInitialized = isParameter || isOuterVariable ||
                 type !== autoType && type !== autoArrayType && (!strictNullChecks || (type.flags & TypeFlags.Any) !== 0 || isInTypeQuery(node) || node.parent.kind === SyntaxKind.ExportSpecifier) ||
+                node.parent.kind === SyntaxKind.NonNullExpression ||
                 isInAmbientContext(declaration);
             const initialType = assumeInitialized ? (isParameter ? removeOptionalityFromDeclaredType(type, getRootDeclaration(declaration) as VariableLikeDeclaration) : type) :
                 type === autoType || type === autoArrayType ? undefinedType :
diff --git a/tests/baselines/reference/typeGuardsAsAssertions.js b/tests/baselines/reference/typeGuardsAsAssertions.js
index 8c9b2048514..692af453c0c 100644
--- a/tests/baselines/reference/typeGuardsAsAssertions.js
+++ b/tests/baselines/reference/typeGuardsAsAssertions.js
@@ -119,6 +119,11 @@ function f6() {
     x = <string | null>"";
     x!.slice();
 }
+
+function f7() {
+    let x: string;
+    x!.slice();
+}
 
 
 //// [typeGuardsAsAssertions.js]
@@ -227,3 +232,7 @@ function f6() {
     x = "";
     x.slice();
 }
+function f7() {
+    var x;
+    x.slice();
+}
diff --git a/tests/baselines/reference/typeGuardsAsAssertions.symbols b/tests/baselines/reference/typeGuardsAsAssertions.symbols
index 71c02412a12..346418871db 100644
--- a/tests/baselines/reference/typeGuardsAsAssertions.symbols
+++ b/tests/baselines/reference/typeGuardsAsAssertions.symbols
@@ -312,3 +312,15 @@ function f6() {
 >slice : Symbol(String.slice, Decl(lib.d.ts, --, --))
 }
 
+function f7() {
+>f7 : Symbol(f7, Decl(typeGuardsAsAssertions.ts, 119, 1))
+
+    let x: string;
+>x : Symbol(x, Decl(typeGuardsAsAssertions.ts, 122, 7))
+
+    x!.slice();
+>x!.slice : Symbol(String.slice, Decl(lib.d.ts, --, --))
+>x : Symbol(x, Decl(typeGuardsAsAssertions.ts, 122, 7))
+>slice : Symbol(String.slice, Decl(lib.d.ts, --, --))
+}
+
diff --git a/tests/baselines/reference/typeGuardsAsAssertions.types b/tests/baselines/reference/typeGuardsAsAssertions.types
index 09378bcee54..bd11b4a6f20 100644
--- a/tests/baselines/reference/typeGuardsAsAssertions.types
+++ b/tests/baselines/reference/typeGuardsAsAssertions.types
@@ -382,3 +382,17 @@ function f6() {
 >slice : (start?: number | undefined, end?: number | undefined) => string
 }
 
+function f7() {
+>f7 : () => void
+
+    let x: string;
+>x : string
+
+    x!.slice();
+>x!.slice() : string
+>x!.slice : (start?: number | undefined, end?: number | undefined) => string
+>x! : string
+>x : string
+>slice : (start?: number | undefined, end?: number | undefined) => string
+}
+
diff --git a/tests/cases/conformance/controlFlow/typeGuardsAsAssertions.ts b/tests/cases/conformance/controlFlow/typeGuardsAsAssertions.ts
index 912eaa64e80..5ce430bc19a 100644
--- a/tests/cases/conformance/controlFlow/typeGuardsAsAssertions.ts
+++ b/tests/cases/conformance/controlFlow/typeGuardsAsAssertions.ts
@@ -120,3 +120,8 @@ function f6() {
     x = <string | null>"";
     x!.slice();
 }
+
+function f7() {
+    let x: string;
+    x!.slice();
+}

From b4ee6b19aac530a208ea2d448b83fbcb61e0f4b7 Mon Sep 17 00:00:00 2001
From: Arthur Ozga <aozgaa@users.noreply.github.com>
Date: Tue, 23 May 2017 14:22:01 -0700
Subject: [PATCH 15/56] Object literal formatting (#16007)

* consolidate object literal formatting

* accept baselines
---
 src/compiler/emitter.ts                       |  5 +-
 .../reference/arrowFunctionExpressions.types  | 20 +++----
 .../contextuallyTypedBindingInitializer.types | 12 ++--
 ...uallyTypedBindingInitializerNegative.types | 12 ++--
 .../reference/contextuallyTypedIife.types     | 16 ++---
 .../controlFlowDestructuringParameters.types  |  2 +-
 .../declarationEmitBindingPatterns.types      |  6 +-
 .../declarationEmitDestructuring1.types       |  4 +-
 ...OptionalBindingParametersInOverloads.types |  4 +-
 .../destructureOptionalParameter.types        |  4 +-
 ...tructuringParameterDeclaration2.errors.txt |  4 +-
 ...estructuringParameterDeclaration7ES5.types |  4 +-
 ...ringParameterDeclaration7ES5iterable.types |  4 +-
 .../destructuringWithGenericParameter.types   |  2 +-
 ...destructuringWithLiteralInitializers.types | 58 +++++++++----------
 .../reference/emitArrowFunctionES6.types      | 20 +++----
 ...ableDeclarationBindingPatterns01_ES5.types |  4 +-
 ...arationBindingPatterns01_ES5iterable.types |  4 +-
 ...ableDeclarationBindingPatterns01_ES6.types |  4 +-
 ...backToBindingPatternForTypeInference.types |  8 +--
 ...licitAnyDestructuringInPrivateMethod.types |  4 +-
 tests/baselines/reference/objectRest.types    |  4 +-
 .../reference/objectRestParameter.types       | 16 ++---
 .../reference/objectRestParameterES5.types    | 16 ++---
 ...erInitializerBeforeDestructuringEmit.types |  2 +-
 ...gParameterNestedObjectBindingPattern.types | 18 +++---
 ...tedObjectBindingPatternDefaultValues.types | 18 +++---
 ...cturingParameterObjectBindingPattern.types | 18 +++---
 ...terObjectBindingPatternDefaultValues.types | 18 +++---
 .../tsxSpreadAttributesResolution13.types     |  6 +-
 .../tsxSpreadAttributesResolution15.types     |  4 +-
 .../reference/tsxSpreadChildren.types         |  4 +-
 ...xStatelessFunctionComponentOverload1.types | 18 +++---
 .../tsxStatelessFunctionComponents3.types     |  2 +-
 34 files changed, 172 insertions(+), 173 deletions(-)

diff --git a/src/compiler/emitter.ts b/src/compiler/emitter.ts
index e00d46fe94e..aef1a61e080 100644
--- a/src/compiler/emitter.ts
+++ b/src/compiler/emitter.ts
@@ -1064,7 +1064,7 @@ namespace ts {
             }
             else {
                 write("{");
-                emitList(node, elements, getEmitFlags(node) & EmitFlags.SingleLine ? ListFormat.ObjectBindingPatternElements : ListFormat.ObjectBindingPatternElementsWithSpaceBetweenBraces);
+                emitList(node, elements, ListFormat.ObjectBindingPatternElements);
                 write("}");
             }
         }
@@ -3019,8 +3019,7 @@ namespace ts {
         TupleTypeElements = CommaDelimited | SpaceBetweenSiblings | SingleLine | Indented,
         UnionTypeConstituents = BarDelimited | SpaceBetweenSiblings | SingleLine,
         IntersectionTypeConstituents = AmpersandDelimited | SpaceBetweenSiblings | SingleLine,
-        ObjectBindingPatternElements = SingleLine | CommaDelimited | SpaceBetweenSiblings,
-        ObjectBindingPatternElementsWithSpaceBetweenBraces = SingleLine | AllowTrailingComma | SpaceBetweenBraces | CommaDelimited | SpaceBetweenSiblings,
+        ObjectBindingPatternElements = SingleLine | AllowTrailingComma | SpaceBetweenBraces | CommaDelimited | SpaceBetweenSiblings,
         ArrayBindingPatternElements = SingleLine | AllowTrailingComma | CommaDelimited | SpaceBetweenSiblings,
         ObjectLiteralExpressionProperties = PreserveLines | CommaDelimited | SpaceBetweenSiblings | SpaceBetweenBraces | Indented | Braces,
         ArrayLiteralExpressionElements = PreserveLines | CommaDelimited | SpaceBetweenSiblings | AllowTrailingComma | Indented | SquareBrackets,
diff --git a/tests/baselines/reference/arrowFunctionExpressions.types b/tests/baselines/reference/arrowFunctionExpressions.types
index aad43240daa..0de6c674d18 100644
--- a/tests/baselines/reference/arrowFunctionExpressions.types
+++ b/tests/baselines/reference/arrowFunctionExpressions.types
@@ -83,25 +83,25 @@ var p5 = ([a = 1]) => { };
 >1 : 1
 
 var p6 = ({ a }) => { };
->p6 : ({a}: { a: any; }) => void
->({ a }) => { } : ({a}: { a: any; }) => void
+>p6 : ({ a }: { a: any; }) => void
+>({ a }) => { } : ({ a }: { a: any; }) => void
 >a : any
 
 var p7 = ({ a: { b } }) => { };
->p7 : ({a: {b}}: { a: { b: any; }; }) => void
->({ a: { b } }) => { } : ({a: {b}}: { a: { b: any; }; }) => void
+>p7 : ({ a: { b } }: { a: { b: any; }; }) => void
+>({ a: { b } }) => { } : ({ a: { b } }: { a: { b: any; }; }) => void
 >a : any
 >b : any
 
 var p8 = ({ a = 1 }) => { };
->p8 : ({a}: { a?: number; }) => void
->({ a = 1 }) => { } : ({a}: { a?: number; }) => void
+>p8 : ({ a }: { a?: number; }) => void
+>({ a = 1 }) => { } : ({ a }: { a?: number; }) => void
 >a : number
 >1 : 1
 
 var p9 = ({ a: { b = 1 } = { b: 1 } }) => { };
->p9 : ({a: {b}}: { a?: { b?: number; }; }) => void
->({ a: { b = 1 } = { b: 1 } }) => { } : ({a: {b}}: { a?: { b?: number; }; }) => void
+>p9 : ({ a: { b } }: { a?: { b?: number; }; }) => void
+>({ a: { b = 1 } = { b: 1 } }) => { } : ({ a: { b } }: { a?: { b?: number; }; }) => void
 >a : any
 >b : number
 >1 : 1
@@ -110,8 +110,8 @@ var p9 = ({ a: { b = 1 } = { b: 1 } }) => { };
 >1 : 1
 
 var p10 = ([{ value, done }]) => { };
->p10 : ([{value, done}]: [{ value: any; done: any; }]) => void
->([{ value, done }]) => { } : ([{value, done}]: [{ value: any; done: any; }]) => void
+>p10 : ([{ value, done }]: [{ value: any; done: any; }]) => void
+>([{ value, done }]) => { } : ([{ value, done }]: [{ value: any; done: any; }]) => void
 >value : any
 >done : any
 
diff --git a/tests/baselines/reference/contextuallyTypedBindingInitializer.types b/tests/baselines/reference/contextuallyTypedBindingInitializer.types
index e9624b156c7..4efd22a4c84 100644
--- a/tests/baselines/reference/contextuallyTypedBindingInitializer.types
+++ b/tests/baselines/reference/contextuallyTypedBindingInitializer.types
@@ -7,7 +7,7 @@ interface Show {
 >x : number
 }
 function f({ show = v => v.toString() }: Show) {}
->f : ({show}: Show) => void
+>f : ({ show }: Show) => void
 >show : (x: number) => string
 >v => v.toString() : (v: number) => string
 >v : number
@@ -18,7 +18,7 @@ function f({ show = v => v.toString() }: Show) {}
 >Show : Show
 
 function f2({ "show": showRename = v => v.toString() }: Show) {}
->f2 : ({"show": showRename}: Show) => void
+>f2 : ({ "show": showRename }: Show) => void
 >showRename : (x: number) => string
 >v => v.toString() : (v: number) => string
 >v : number
@@ -29,7 +29,7 @@ function f2({ "show": showRename = v => v.toString() }: Show) {}
 >Show : Show
 
 function f3({ ["show"]: showRename = v => v.toString() }: Show) {}
->f3 : ({["show"]: showRename}: Show) => void
+>f3 : ({ ["show"]: showRename }: Show) => void
 >"show" : "show"
 >showRename : (x: number) => string
 >v => v.toString() : (v: number) => string
@@ -48,7 +48,7 @@ interface Nested {
 >Show : Show
 }
 function ff({ nested = { show: v => v.toString() } }: Nested) {}
->ff : ({nested}: Nested) => void
+>ff : ({ nested }: Nested) => void
 >nested : Show
 >{ show: v => v.toString() } : { show: (v: number) => string; }
 >show : (v: number) => string
@@ -67,7 +67,7 @@ interface Tuples {
 >prop : [string, number]
 }
 function g({ prop = ["hello", 1234] }: Tuples) {}
->g : ({prop}: Tuples) => void
+>g : ({ prop }: Tuples) => void
 >prop : [string, number]
 >["hello", 1234] : [string, number]
 >"hello" : "hello"
@@ -81,7 +81,7 @@ interface StringUnion {
 >prop : "foo" | "bar"
 }
 function h({ prop = "foo" }: StringUnion) {}
->h : ({prop}: StringUnion) => void
+>h : ({ prop }: StringUnion) => void
 >prop : "foo" | "bar"
 >"foo" : "foo"
 >StringUnion : StringUnion
diff --git a/tests/baselines/reference/contextuallyTypedBindingInitializerNegative.types b/tests/baselines/reference/contextuallyTypedBindingInitializerNegative.types
index 5adc82c3e62..1548e626e6d 100644
--- a/tests/baselines/reference/contextuallyTypedBindingInitializerNegative.types
+++ b/tests/baselines/reference/contextuallyTypedBindingInitializerNegative.types
@@ -7,7 +7,7 @@ interface Show {
 >x : number
 }
 function f({ show: showRename = v => v }: Show) {}
->f : ({show: showRename}: Show) => void
+>f : ({ show: showRename }: Show) => void
 >show : any
 >showRename : ((x: number) => string) | ((v: number) => number)
 >v => v : (v: number) => number
@@ -16,7 +16,7 @@ function f({ show: showRename = v => v }: Show) {}
 >Show : Show
 
 function f2({ "show": showRename = v => v }: Show) {}
->f2 : ({"show": showRename}: Show) => void
+>f2 : ({ "show": showRename }: Show) => void
 >showRename : ((x: number) => string) | ((v: number) => number)
 >v => v : (v: number) => number
 >v : number
@@ -24,7 +24,7 @@ function f2({ "show": showRename = v => v }: Show) {}
 >Show : Show
 
 function f3({ ["show"]: showRename = v => v }: Show) {}
->f3 : ({["show"]: showRename}: Show) => void
+>f3 : ({ ["show"]: showRename }: Show) => void
 >"show" : "show"
 >showRename : ((x: number) => string) | ((v: number) => number)
 >v => v : (v: number) => number
@@ -40,7 +40,7 @@ interface Nested {
 >Show : Show
 }
 function ff({ nested: nestedRename = { show: v => v } }: Nested) {}
->ff : ({nested: nestedRename}: Nested) => void
+>ff : ({ nested: nestedRename }: Nested) => void
 >nested : any
 >nestedRename : Show | { show: (v: number) => number; }
 >{ show: v => v } : { show: (v: number) => number; }
@@ -79,7 +79,7 @@ interface Tuples {
 >prop : [string, number]
 }
 function g({ prop = [101, 1234] }: Tuples) {}
->g : ({prop}: Tuples) => void
+>g : ({ prop }: Tuples) => void
 >prop : [string, number] | [number, number]
 >[101, 1234] : [number, number]
 >101 : 101
@@ -93,7 +93,7 @@ interface StringUnion {
 >prop : "foo" | "bar"
 }
 function h({ prop = "baz" }: StringUnion) {}
->h : ({prop}: StringUnion) => void
+>h : ({ prop }: StringUnion) => void
 >prop : "foo" | "bar" | "baz"
 >"baz" : "baz"
 >StringUnion : StringUnion
diff --git a/tests/baselines/reference/contextuallyTypedIife.types b/tests/baselines/reference/contextuallyTypedIife.types
index 04ddbf50fde..77bb40df903 100644
--- a/tests/baselines/reference/contextuallyTypedIife.types
+++ b/tests/baselines/reference/contextuallyTypedIife.types
@@ -175,8 +175,8 @@
 // destructuring parameters (with defaults too!)
 (({ q }) => q)({ q : 13 });
 >(({ q }) => q)({ q : 13 }) : number
->(({ q }) => q) : ({q}: { q: number; }) => number
->({ q }) => q : ({q}: { q: number; }) => number
+>(({ q }) => q) : ({ q }: { q: number; }) => number
+>({ q }) => q : ({ q }: { q: number; }) => number
 >q : number
 >q : number
 >{ q : 13 } : { q: number; }
@@ -185,8 +185,8 @@
 
 (({ p = 14 }) => p)({ p : 15 });
 >(({ p = 14 }) => p)({ p : 15 }) : number
->(({ p = 14 }) => p) : ({p}: { p: number; }) => number
->({ p = 14 }) => p : ({p}: { p: number; }) => number
+>(({ p = 14 }) => p) : ({ p }: { p: number; }) => number
+>({ p = 14 }) => p : ({ p }: { p: number; }) => number
 >p : number
 >14 : 14
 >p : number
@@ -196,8 +196,8 @@
 
 (({ r = 17 } = { r: 18 }) => r)({r : 19});
 >(({ r = 17 } = { r: 18 }) => r)({r : 19}) : number
->(({ r = 17 } = { r: 18 }) => r) : ({r}?: { r: number; }) => number
->({ r = 17 } = { r: 18 }) => r : ({r}?: { r: number; }) => number
+>(({ r = 17 } = { r: 18 }) => r) : ({ r }?: { r: number; }) => number
+>({ r = 17 } = { r: 18 }) => r : ({ r }?: { r: number; }) => number
 >r : number
 >17 : 17
 >{ r: 18 } : { r: number; }
@@ -210,8 +210,8 @@
 
 (({ u = 22 } = { u: 23 }) => u)();
 >(({ u = 22 } = { u: 23 }) => u)() : number
->(({ u = 22 } = { u: 23 }) => u) : ({u}?: { u?: number; }) => number
->({ u = 22 } = { u: 23 }) => u : ({u}?: { u?: number; }) => number
+>(({ u = 22 } = { u: 23 }) => u) : ({ u }?: { u?: number; }) => number
+>({ u = 22 } = { u: 23 }) => u : ({ u }?: { u?: number; }) => number
 >u : number
 >22 : 22
 >{ u: 23 } : { u?: number; }
diff --git a/tests/baselines/reference/controlFlowDestructuringParameters.types b/tests/baselines/reference/controlFlowDestructuringParameters.types
index 7fdb1eded01..44755dca81b 100644
--- a/tests/baselines/reference/controlFlowDestructuringParameters.types
+++ b/tests/baselines/reference/controlFlowDestructuringParameters.types
@@ -12,7 +12,7 @@
 >map : { <U>(this: [{ x: number; }, { x: number; }, { x: number; }, { x: number; }, { x: number; }], callbackfn: (this: void, value: { x: number; }, index: number, array: { x: number; }[]) => U): [U, U, U, U, U]; <U>(this: [{ x: number; }, { x: number; }, { x: number; }, { x: number; }, { x: number; }], callbackfn: (this: void, value: { x: number; }, index: number, array: { x: number; }[]) => U, thisArg: undefined): [U, U, U, U, U]; <Z, U>(this: [{ x: number; }, { x: number; }, { x: number; }, { x: number; }, { x: number; }], callbackfn: (this: Z, value: { x: number; }, index: number, array: { x: number; }[]) => U, thisArg: Z): [U, U, U, U, U]; <U>(this: [{ x: number; }, { x: number; }, { x: number; }, { x: number; }], callbackfn: (this: void, value: { x: number; }, index: number, array: { x: number; }[]) => U): [U, U, U, U]; <U>(this: [{ x: number; }, { x: number; }, { x: number; }, { x: number; }], callbackfn: (this: void, value: { x: number; }, index: number, array: { x: number; }[]) => U, thisArg: undefined): [U, U, U, U]; <Z, U>(this: [{ x: number; }, { x: number; }, { x: number; }, { x: number; }], callbackfn: (this: Z, value: { x: number; }, index: number, array: { x: number; }[]) => U, thisArg: Z): [U, U, U, U]; <U>(this: [{ x: number; }, { x: number; }, { x: number; }], callbackfn: (this: void, value: { x: number; }, index: number, array: { x: number; }[]) => U): [U, U, U]; <U>(this: [{ x: number; }, { x: number; }, { x: number; }], callbackfn: (this: void, value: { x: number; }, index: number, array: { x: number; }[]) => U, thisArg: undefined): [U, U, U]; <Z, U>(this: [{ x: number; }, { x: number; }, { x: number; }], callbackfn: (this: Z, value: { x: number; }, index: number, array: { x: number; }[]) => U, thisArg: Z): [U, U, U]; <U>(this: [{ x: number; }, { x: number; }], callbackfn: (this: void, value: { x: number; }, index: number, array: { x: number; }[]) => U): [U, U]; <U>(this: [{ x: number; }, { x: number; }], callbackfn: (this: void, value: { x: number; }, index: number, array: { x: number; }[]) => U, thisArg: undefined): [U, U]; <Z, U>(this: [{ x: number; }, { x: number; }], callbackfn: (this: Z, value: { x: number; }, index: number, array: { x: number; }[]) => U, thisArg: Z): [U, U]; <U>(callbackfn: (this: void, value: { x: number; }, index: number, array: { x: number; }[]) => U): U[]; <U>(callbackfn: (this: void, value: { x: number; }, index: number, array: { x: number; }[]) => U, thisArg: undefined): U[]; <Z, U>(callbackfn: (this: Z, value: { x: number; }, index: number, array: { x: number; }[]) => U, thisArg: Z): U[]; }
 
   ({ x }) => x
->({ x }) => x : (this: void, {x}: { x: number; }) => number
+>({ x }) => x : (this: void, { x }: { x: number; }) => number
 >x : number
 >x : number
 
diff --git a/tests/baselines/reference/declarationEmitBindingPatterns.types b/tests/baselines/reference/declarationEmitBindingPatterns.types
index 1a47fbebf07..d49893dad94 100644
--- a/tests/baselines/reference/declarationEmitBindingPatterns.types
+++ b/tests/baselines/reference/declarationEmitBindingPatterns.types
@@ -1,7 +1,7 @@
 === tests/cases/compiler/declarationEmitBindingPatterns.ts ===
 const k = ({x: z = 'y'}) => { }
->k : ({x: z}: { x?: string; }) => void
->({x: z = 'y'}) => { } : ({x: z}: { x?: string; }) => void
+>k : ({ x: z }: { x?: string; }) => void
+>({x: z = 'y'}) => { } : ({ x: z }: { x?: string; }) => void
 >x : any
 >z : string
 >'y' : "y"
@@ -10,7 +10,7 @@ var a;
 >a : any
 
 function f({} = a, [] = a, { p: {} = a} = a) {
->f : ({}?: any, []?: any, {p: {}}?: any) => void
+>f : ({}?: any, []?: any, { p: {} }?: any) => void
 >a : any
 >a : any
 >p : any
diff --git a/tests/baselines/reference/declarationEmitDestructuring1.types b/tests/baselines/reference/declarationEmitDestructuring1.types
index abba67981d8..161ad94e54a 100644
--- a/tests/baselines/reference/declarationEmitDestructuring1.types
+++ b/tests/baselines/reference/declarationEmitDestructuring1.types
@@ -12,7 +12,7 @@ function far([a, [b], [[c]]]: [number, boolean[], string[][]]): void { }
 >c : string
 
 function bar({a1, b1, c1}: { a1: number, b1: boolean, c1: string }): void { }
->bar : ({a1, b1, c1}: { a1: number; b1: boolean; c1: string; }) => void
+>bar : ({ a1, b1, c1 }: { a1: number; b1: boolean; c1: string; }) => void
 >a1 : number
 >b1 : boolean
 >c1 : string
@@ -21,7 +21,7 @@ function bar({a1, b1, c1}: { a1: number, b1: boolean, c1: string }): void { }
 >c1 : string
 
 function baz({a2, b2: {b1, c1}}: { a2: number, b2: { b1: boolean, c1: string } }): void { } 
->baz : ({a2, b2: {b1, c1}}: { a2: number; b2: { b1: boolean; c1: string; }; }) => void
+>baz : ({ a2, b2: { b1, c1 } }: { a2: number; b2: { b1: boolean; c1: string; }; }) => void
 >a2 : number
 >b2 : any
 >b1 : boolean
diff --git a/tests/baselines/reference/declarationEmitDestructuringOptionalBindingParametersInOverloads.types b/tests/baselines/reference/declarationEmitDestructuringOptionalBindingParametersInOverloads.types
index 0bf290bcf7d..fb8c57d019b 100644
--- a/tests/baselines/reference/declarationEmitDestructuringOptionalBindingParametersInOverloads.types
+++ b/tests/baselines/reference/declarationEmitDestructuringOptionalBindingParametersInOverloads.types
@@ -11,7 +11,7 @@ function foo(...rest: any[]) {
 }
 
 function foo2( { x, y, z }?: { x: string; y: number; z: boolean });
->foo2 : ({x, y, z}?: { x: string; y: number; z: boolean; }) => any
+>foo2 : ({ x, y, z }?: { x: string; y: number; z: boolean; }) => any
 >x : string
 >y : number
 >z : boolean
@@ -20,7 +20,7 @@ function foo2( { x, y, z }?: { x: string; y: number; z: boolean });
 >z : boolean
 
 function foo2(...rest: any[]) {
->foo2 : ({x, y, z}?: { x: string; y: number; z: boolean; }) => any
+>foo2 : ({ x, y, z }?: { x: string; y: number; z: boolean; }) => any
 >rest : any[]
 
 }
diff --git a/tests/baselines/reference/destructureOptionalParameter.types b/tests/baselines/reference/destructureOptionalParameter.types
index f007a992c9e..18a6d7675dd 100644
--- a/tests/baselines/reference/destructureOptionalParameter.types
+++ b/tests/baselines/reference/destructureOptionalParameter.types
@@ -1,13 +1,13 @@
 === tests/cases/compiler/destructureOptionalParameter.ts ===
 declare function f1({ a, b }?: { a: number, b: string }): void;
->f1 : ({a, b}?: { a: number; b: string; } | undefined) => void
+>f1 : ({ a, b }?: { a: number; b: string; } | undefined) => void
 >a : number
 >b : string
 >a : number
 >b : string
 
 function f2({ a, b }: { a: number, b: number } = { a: 0, b: 0 }) {
->f2 : ({a, b}?: { a: number; b: number; }) => void
+>f2 : ({ a, b }?: { a: number; b: number; }) => void
 >a : number
 >b : number
 >a : number
diff --git a/tests/baselines/reference/destructuringParameterDeclaration2.errors.txt b/tests/baselines/reference/destructuringParameterDeclaration2.errors.txt
index d76a4efe5f1..81c85f7c42b 100644
--- a/tests/baselines/reference/destructuringParameterDeclaration2.errors.txt
+++ b/tests/baselines/reference/destructuringParameterDeclaration2.errors.txt
@@ -38,7 +38,7 @@ tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration2.ts(
 tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration2.ts(47,13): error TS2463: A binding pattern parameter cannot be optional in an implementation signature.
 tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration2.ts(55,7): error TS2420: Class 'C4' incorrectly implements interface 'F2'.
   Types of property 'd4' are incompatible.
-    Type '({x, y, c}: { x: any; y: any; c: any; }) => void' is not assignable to type '({x, y, z}?: { x: any; y: any; z: any; }) => any'.
+    Type '({ x, y, c }: { x: any; y: any; c: any; }) => void' is not assignable to type '({ x, y, z }?: { x: any; y: any; z: any; }) => any'.
       Types of parameters '__0' and '__0' are incompatible.
         Type '{ x: any; y: any; z: any; }' is not assignable to type '{ x: any; y: any; c: any; }'.
           Property 'c' is missing in type '{ x: any; y: any; z: any; }'.
@@ -162,7 +162,7 @@ tests/cases/conformance/es6/destructuring/destructuringParameterDeclaration2.ts(
           ~~
 !!! error TS2420: Class 'C4' incorrectly implements interface 'F2'.
 !!! error TS2420:   Types of property 'd4' are incompatible.
-!!! error TS2420:     Type '({x, y, c}: { x: any; y: any; c: any; }) => void' is not assignable to type '({x, y, z}?: { x: any; y: any; z: any; }) => any'.
+!!! error TS2420:     Type '({ x, y, c }: { x: any; y: any; c: any; }) => void' is not assignable to type '({ x, y, z }?: { x: any; y: any; z: any; }) => any'.
 !!! error TS2420:       Types of parameters '__0' and '__0' are incompatible.
 !!! error TS2420:         Type '{ x: any; y: any; z: any; }' is not assignable to type '{ x: any; y: any; c: any; }'.
 !!! error TS2420:           Property 'c' is missing in type '{ x: any; y: any; z: any; }'.
diff --git a/tests/baselines/reference/destructuringParameterDeclaration7ES5.types b/tests/baselines/reference/destructuringParameterDeclaration7ES5.types
index 502a176596a..40a07f02276 100644
--- a/tests/baselines/reference/destructuringParameterDeclaration7ES5.types
+++ b/tests/baselines/reference/destructuringParameterDeclaration7ES5.types
@@ -10,13 +10,13 @@ interface ISomething {
 }
 
 function foo({}, {foo, bar}: ISomething) {}
->foo : ({}: {}, {foo, bar}: ISomething) => void
+>foo : ({}: {}, { foo, bar }: ISomething) => void
 >foo : string
 >bar : string
 >ISomething : ISomething
 
 function baz([], {foo, bar}: ISomething) {}
->baz : ([]: any[], {foo, bar}: ISomething) => void
+>baz : ([]: any[], { foo, bar }: ISomething) => void
 >foo : string
 >bar : string
 >ISomething : ISomething
diff --git a/tests/baselines/reference/destructuringParameterDeclaration7ES5iterable.types b/tests/baselines/reference/destructuringParameterDeclaration7ES5iterable.types
index 542407cabe2..607c34cdd37 100644
--- a/tests/baselines/reference/destructuringParameterDeclaration7ES5iterable.types
+++ b/tests/baselines/reference/destructuringParameterDeclaration7ES5iterable.types
@@ -10,13 +10,13 @@ interface ISomething {
 }
 
 function foo({}, {foo, bar}: ISomething) {}
->foo : ({}: {}, {foo, bar}: ISomething) => void
+>foo : ({}: {}, { foo, bar }: ISomething) => void
 >foo : string
 >bar : string
 >ISomething : ISomething
 
 function baz([], {foo, bar}: ISomething) {}
->baz : ([]: any[], {foo, bar}: ISomething) => void
+>baz : ([]: any[], { foo, bar }: ISomething) => void
 >foo : string
 >bar : string
 >ISomething : ISomething
diff --git a/tests/baselines/reference/destructuringWithGenericParameter.types b/tests/baselines/reference/destructuringWithGenericParameter.types
index 07a86e679a9..430d6e0faca 100644
--- a/tests/baselines/reference/destructuringWithGenericParameter.types
+++ b/tests/baselines/reference/destructuringWithGenericParameter.types
@@ -36,7 +36,7 @@ genericFunction(genericObject, ({greeting}) => {
 >genericFunction(genericObject, ({greeting}) => {    var s = greeting.toLocaleLowerCase();  // Greeting should be of type string}) : void
 >genericFunction : <T>(object: GenericClass<T>, callback: (payload: T) => void) => void
 >genericObject : GenericClass<{ greeting: string; }>
->({greeting}) => {    var s = greeting.toLocaleLowerCase();  // Greeting should be of type string} : ({greeting}: { greeting: string; }) => void
+>({greeting}) => {    var s = greeting.toLocaleLowerCase();  // Greeting should be of type string} : ({ greeting }: { greeting: string; }) => void
 >greeting : string
 
     var s = greeting.toLocaleLowerCase();  // Greeting should be of type string
diff --git a/tests/baselines/reference/destructuringWithLiteralInitializers.types b/tests/baselines/reference/destructuringWithLiteralInitializers.types
index 43391515014..51c432f7605 100644
--- a/tests/baselines/reference/destructuringWithLiteralInitializers.types
+++ b/tests/baselines/reference/destructuringWithLiteralInitializers.types
@@ -1,13 +1,13 @@
 === tests/cases/conformance/es6/destructuring/destructuringWithLiteralInitializers.ts ===
 // (arg: { x: any, y: any }) => void
 function f1({ x, y }) { }
->f1 : ({x, y}: { x: any; y: any; }) => void
+>f1 : ({ x, y }: { x: any; y: any; }) => void
 >x : any
 >y : any
 
 f1({ x: 1, y: 1 });
 >f1({ x: 1, y: 1 }) : void
->f1 : ({x, y}: { x: any; y: any; }) => void
+>f1 : ({ x, y }: { x: any; y: any; }) => void
 >{ x: 1, y: 1 } : { x: number; y: number; }
 >x : number
 >1 : 1
@@ -16,21 +16,21 @@ f1({ x: 1, y: 1 });
 
 // (arg: { x: any, y?: number }) => void
 function f2({ x, y = 0 }) { }
->f2 : ({x, y}: { x: any; y?: number; }) => void
+>f2 : ({ x, y }: { x: any; y?: number; }) => void
 >x : any
 >y : number
 >0 : 0
 
 f2({ x: 1 });
 >f2({ x: 1 }) : void
->f2 : ({x, y}: { x: any; y?: number; }) => void
+>f2 : ({ x, y }: { x: any; y?: number; }) => void
 >{ x: 1 } : { x: number; }
 >x : number
 >1 : 1
 
 f2({ x: 1, y: 1 });
 >f2({ x: 1, y: 1 }) : void
->f2 : ({x, y}: { x: any; y?: number; }) => void
+>f2 : ({ x, y }: { x: any; y?: number; }) => void
 >{ x: 1, y: 1 } : { x: number; y: number; }
 >x : number
 >1 : 1
@@ -39,7 +39,7 @@ f2({ x: 1, y: 1 });
 
 // (arg: { x?: number, y?: number }) => void
 function f3({ x = 0, y = 0 }) { }
->f3 : ({x, y}: { x?: number; y?: number; }) => void
+>f3 : ({ x, y }: { x?: number; y?: number; }) => void
 >x : number
 >0 : 0
 >y : number
@@ -47,26 +47,26 @@ function f3({ x = 0, y = 0 }) { }
 
 f3({});
 >f3({}) : void
->f3 : ({x, y}: { x?: number; y?: number; }) => void
+>f3 : ({ x, y }: { x?: number; y?: number; }) => void
 >{} : {}
 
 f3({ x: 1 });
 >f3({ x: 1 }) : void
->f3 : ({x, y}: { x?: number; y?: number; }) => void
+>f3 : ({ x, y }: { x?: number; y?: number; }) => void
 >{ x: 1 } : { x: number; }
 >x : number
 >1 : 1
 
 f3({ y: 1 });
 >f3({ y: 1 }) : void
->f3 : ({x, y}: { x?: number; y?: number; }) => void
+>f3 : ({ x, y }: { x?: number; y?: number; }) => void
 >{ y: 1 } : { y: number; }
 >y : number
 >1 : 1
 
 f3({ x: 1, y: 1 });
 >f3({ x: 1, y: 1 }) : void
->f3 : ({x, y}: { x?: number; y?: number; }) => void
+>f3 : ({ x, y }: { x?: number; y?: number; }) => void
 >{ x: 1, y: 1 } : { x: number; y: number; }
 >x : number
 >1 : 1
@@ -75,7 +75,7 @@ f3({ x: 1, y: 1 });
 
 // (arg?: { x: number, y: number }) => void
 function f4({ x, y } = { x: 0, y: 0 }) { }
->f4 : ({x, y}?: { x: number; y: number; }) => void
+>f4 : ({ x, y }?: { x: number; y: number; }) => void
 >x : number
 >y : number
 >{ x: 0, y: 0 } : { x: number; y: number; }
@@ -86,11 +86,11 @@ function f4({ x, y } = { x: 0, y: 0 }) { }
 
 f4();
 >f4() : void
->f4 : ({x, y}?: { x: number; y: number; }) => void
+>f4 : ({ x, y }?: { x: number; y: number; }) => void
 
 f4({ x: 1, y: 1 });
 >f4({ x: 1, y: 1 }) : void
->f4 : ({x, y}?: { x: number; y: number; }) => void
+>f4 : ({ x, y }?: { x: number; y: number; }) => void
 >{ x: 1, y: 1 } : { x: number; y: number; }
 >x : number
 >1 : 1
@@ -99,7 +99,7 @@ f4({ x: 1, y: 1 });
 
 // (arg?: { x: number, y?: number }) => void
 function f5({ x, y = 0 } = { x: 0 }) { }
->f5 : ({x, y}?: { x: number; y?: number; }) => void
+>f5 : ({ x, y }?: { x: number; y?: number; }) => void
 >x : number
 >y : number
 >0 : 0
@@ -109,18 +109,18 @@ function f5({ x, y = 0 } = { x: 0 }) { }
 
 f5();
 >f5() : void
->f5 : ({x, y}?: { x: number; y?: number; }) => void
+>f5 : ({ x, y }?: { x: number; y?: number; }) => void
 
 f5({ x: 1 });
 >f5({ x: 1 }) : void
->f5 : ({x, y}?: { x: number; y?: number; }) => void
+>f5 : ({ x, y }?: { x: number; y?: number; }) => void
 >{ x: 1 } : { x: number; }
 >x : number
 >1 : 1
 
 f5({ x: 1, y: 1 });
 >f5({ x: 1, y: 1 }) : void
->f5 : ({x, y}?: { x: number; y?: number; }) => void
+>f5 : ({ x, y }?: { x: number; y?: number; }) => void
 >{ x: 1, y: 1 } : { x: number; y: number; }
 >x : number
 >1 : 1
@@ -129,7 +129,7 @@ f5({ x: 1, y: 1 });
 
 // (arg?: { x?: number, y?: number }) => void
 function f6({ x = 0, y = 0 } = {}) { }
->f6 : ({x, y}?: { x?: number; y?: number; }) => void
+>f6 : ({ x, y }?: { x?: number; y?: number; }) => void
 >x : number
 >0 : 0
 >y : number
@@ -138,30 +138,30 @@ function f6({ x = 0, y = 0 } = {}) { }
 
 f6();
 >f6() : void
->f6 : ({x, y}?: { x?: number; y?: number; }) => void
+>f6 : ({ x, y }?: { x?: number; y?: number; }) => void
 
 f6({});
 >f6({}) : void
->f6 : ({x, y}?: { x?: number; y?: number; }) => void
+>f6 : ({ x, y }?: { x?: number; y?: number; }) => void
 >{} : {}
 
 f6({ x: 1 });
 >f6({ x: 1 }) : void
->f6 : ({x, y}?: { x?: number; y?: number; }) => void
+>f6 : ({ x, y }?: { x?: number; y?: number; }) => void
 >{ x: 1 } : { x: number; }
 >x : number
 >1 : 1
 
 f6({ y: 1 });
 >f6({ y: 1 }) : void
->f6 : ({x, y}?: { x?: number; y?: number; }) => void
+>f6 : ({ x, y }?: { x?: number; y?: number; }) => void
 >{ y: 1 } : { y: number; }
 >y : number
 >1 : 1
 
 f6({ x: 1, y: 1 });
 >f6({ x: 1, y: 1 }) : void
->f6 : ({x, y}?: { x?: number; y?: number; }) => void
+>f6 : ({ x, y }?: { x?: number; y?: number; }) => void
 >{ x: 1, y: 1 } : { x: number; y: number; }
 >x : number
 >1 : 1
@@ -170,7 +170,7 @@ f6({ x: 1, y: 1 });
 
 // (arg?: { a: { x?: number, y?: number } }) => void
 function f7({ a: { x = 0, y = 0 } } = { a: {} }) { }
->f7 : ({a: {x, y}}?: { a: { x?: number; y?: number; }; }) => void
+>f7 : ({ a: { x, y } }?: { a: { x?: number; y?: number; }; }) => void
 >a : any
 >x : number
 >0 : 0
@@ -182,18 +182,18 @@ function f7({ a: { x = 0, y = 0 } } = { a: {} }) { }
 
 f7();
 >f7() : void
->f7 : ({a: {x, y}}?: { a: { x?: number; y?: number; }; }) => void
+>f7 : ({ a: { x, y } }?: { a: { x?: number; y?: number; }; }) => void
 
 f7({ a: {} });
 >f7({ a: {} }) : void
->f7 : ({a: {x, y}}?: { a: { x?: number; y?: number; }; }) => void
+>f7 : ({ a: { x, y } }?: { a: { x?: number; y?: number; }; }) => void
 >{ a: {} } : { a: {}; }
 >a : {}
 >{} : {}
 
 f7({ a: { x: 1 } });
 >f7({ a: { x: 1 } }) : void
->f7 : ({a: {x, y}}?: { a: { x?: number; y?: number; }; }) => void
+>f7 : ({ a: { x, y } }?: { a: { x?: number; y?: number; }; }) => void
 >{ a: { x: 1 } } : { a: { x: number; }; }
 >a : { x: number; }
 >{ x: 1 } : { x: number; }
@@ -202,7 +202,7 @@ f7({ a: { x: 1 } });
 
 f7({ a: { y: 1 } });
 >f7({ a: { y: 1 } }) : void
->f7 : ({a: {x, y}}?: { a: { x?: number; y?: number; }; }) => void
+>f7 : ({ a: { x, y } }?: { a: { x?: number; y?: number; }; }) => void
 >{ a: { y: 1 } } : { a: { y: number; }; }
 >a : { y: number; }
 >{ y: 1 } : { y: number; }
@@ -211,7 +211,7 @@ f7({ a: { y: 1 } });
 
 f7({ a: { x: 1, y: 1 } });
 >f7({ a: { x: 1, y: 1 } }) : void
->f7 : ({a: {x, y}}?: { a: { x?: number; y?: number; }; }) => void
+>f7 : ({ a: { x, y } }?: { a: { x?: number; y?: number; }; }) => void
 >{ a: { x: 1, y: 1 } } : { a: { x: number; y: number; }; }
 >a : { x: number; y: number; }
 >{ x: 1, y: 1 } : { x: number; y: number; }
diff --git a/tests/baselines/reference/emitArrowFunctionES6.types b/tests/baselines/reference/emitArrowFunctionES6.types
index c434e4b285a..314d5e464b7 100644
--- a/tests/baselines/reference/emitArrowFunctionES6.types
+++ b/tests/baselines/reference/emitArrowFunctionES6.types
@@ -70,25 +70,25 @@ var p5 = ([a = 1]) => { };
 >1 : 1
 
 var p6 = ({ a }) => { };
->p6 : ({a}: { a: any; }) => void
->({ a }) => { } : ({a}: { a: any; }) => void
+>p6 : ({ a }: { a: any; }) => void
+>({ a }) => { } : ({ a }: { a: any; }) => void
 >a : any
 
 var p7 = ({ a: { b } }) => { };
->p7 : ({a: {b}}: { a: { b: any; }; }) => void
->({ a: { b } }) => { } : ({a: {b}}: { a: { b: any; }; }) => void
+>p7 : ({ a: { b } }: { a: { b: any; }; }) => void
+>({ a: { b } }) => { } : ({ a: { b } }: { a: { b: any; }; }) => void
 >a : any
 >b : any
 
 var p8 = ({ a = 1 }) => { };
->p8 : ({a}: { a?: number; }) => void
->({ a = 1 }) => { } : ({a}: { a?: number; }) => void
+>p8 : ({ a }: { a?: number; }) => void
+>({ a = 1 }) => { } : ({ a }: { a?: number; }) => void
 >a : number
 >1 : 1
 
 var p9 = ({ a: { b = 1 } = { b: 1 } }) => { };
->p9 : ({a: {b}}: { a?: { b?: number; }; }) => void
->({ a: { b = 1 } = { b: 1 } }) => { } : ({a: {b}}: { a?: { b?: number; }; }) => void
+>p9 : ({ a: { b } }: { a?: { b?: number; }; }) => void
+>({ a: { b = 1 } = { b: 1 } }) => { } : ({ a: { b } }: { a?: { b?: number; }; }) => void
 >a : any
 >b : number
 >1 : 1
@@ -97,8 +97,8 @@ var p9 = ({ a: { b = 1 } = { b: 1 } }) => { };
 >1 : 1
 
 var p10 = ([{ value, done }]) => { };
->p10 : ([{value, done}]: [{ value: any; done: any; }]) => void
->([{ value, done }]) => { } : ([{value, done}]: [{ value: any; done: any; }]) => void
+>p10 : ([{ value, done }]: [{ value: any; done: any; }]) => void
+>([{ value, done }]) => { } : ([{ value, done }]: [{ value: any; done: any; }]) => void
 >value : any
 >done : any
 
diff --git a/tests/baselines/reference/emptyVariableDeclarationBindingPatterns01_ES5.types b/tests/baselines/reference/emptyVariableDeclarationBindingPatterns01_ES5.types
index c61c80c5b3d..7db78f29829 100644
--- a/tests/baselines/reference/emptyVariableDeclarationBindingPatterns01_ES5.types
+++ b/tests/baselines/reference/emptyVariableDeclarationBindingPatterns01_ES5.types
@@ -61,7 +61,7 @@
     }
 
     function f({} = a, [] = a, { p: {} = a} = a) {
->f : ({}?: any, []?: any, {p: {}}?: any) => ({}?: any, []?: any, {p: {}}?: any) => any
+>f : ({}?: any, []?: any, { p: {} }?: any) => ({}?: any, []?: any, { p: {} }?: any) => any
 >a : any
 >a : any
 >p : any
@@ -69,7 +69,7 @@
 >a : any
 
         return ({} = a, [] = a, { p: {} = a } = a) => a;
->({} = a, [] = a, { p: {} = a } = a) => a : ({}?: any, []?: any, {p: {}}?: any) => any
+>({} = a, [] = a, { p: {} = a } = a) => a : ({}?: any, []?: any, { p: {} }?: any) => any
 >a : any
 >a : any
 >p : any
diff --git a/tests/baselines/reference/emptyVariableDeclarationBindingPatterns01_ES5iterable.types b/tests/baselines/reference/emptyVariableDeclarationBindingPatterns01_ES5iterable.types
index 9c623fd8879..d5559047aba 100644
--- a/tests/baselines/reference/emptyVariableDeclarationBindingPatterns01_ES5iterable.types
+++ b/tests/baselines/reference/emptyVariableDeclarationBindingPatterns01_ES5iterable.types
@@ -61,7 +61,7 @@
     }
 
     function f({} = a, [] = a, { p: {} = a} = a) {
->f : ({}?: any, []?: any, {p: {}}?: any) => ({}?: any, []?: any, {p: {}}?: any) => any
+>f : ({}?: any, []?: any, { p: {} }?: any) => ({}?: any, []?: any, { p: {} }?: any) => any
 >a : any
 >a : any
 >p : any
@@ -69,7 +69,7 @@
 >a : any
 
         return ({} = a, [] = a, { p: {} = a } = a) => a;
->({} = a, [] = a, { p: {} = a } = a) => a : ({}?: any, []?: any, {p: {}}?: any) => any
+>({} = a, [] = a, { p: {} = a } = a) => a : ({}?: any, []?: any, { p: {} }?: any) => any
 >a : any
 >a : any
 >p : any
diff --git a/tests/baselines/reference/emptyVariableDeclarationBindingPatterns01_ES6.types b/tests/baselines/reference/emptyVariableDeclarationBindingPatterns01_ES6.types
index 48d5f40b971..535562296a3 100644
--- a/tests/baselines/reference/emptyVariableDeclarationBindingPatterns01_ES6.types
+++ b/tests/baselines/reference/emptyVariableDeclarationBindingPatterns01_ES6.types
@@ -61,7 +61,7 @@
     }
 
     function f({} = a, [] = a, { p: {} = a} = a) {
->f : ({}?: any, []?: any, {p: {}}?: any) => ({}?: any, []?: any, {p: {}}?: any) => any
+>f : ({}?: any, []?: any, { p: {} }?: any) => ({}?: any, []?: any, { p: {} }?: any) => any
 >a : any
 >a : any
 >p : any
@@ -69,7 +69,7 @@
 >a : any
 
         return ({} = a, [] = a, { p: {} = a } = a) => a;
->({} = a, [] = a, { p: {} = a } = a) => a : ({}?: any, []?: any, {p: {}}?: any) => any
+>({} = a, [] = a, { p: {} = a } = a) => a : ({}?: any, []?: any, { p: {} }?: any) => any
 >a : any
 >a : any
 >p : any
diff --git a/tests/baselines/reference/fallbackToBindingPatternForTypeInference.types b/tests/baselines/reference/fallbackToBindingPatternForTypeInference.types
index 7b1a2d8e6ff..161870de77c 100644
--- a/tests/baselines/reference/fallbackToBindingPatternForTypeInference.types
+++ b/tests/baselines/reference/fallbackToBindingPatternForTypeInference.types
@@ -9,7 +9,7 @@ declare function trans<T>(f: (x: T) => string): number;
 trans(({a}) => a);
 >trans(({a}) => a) : number
 >trans : <T>(f: (x: T) => string) => number
->({a}) => a : ({a}: { a: any; }) => any
+>({a}) => a : ({ a }: { a: any; }) => any
 >a : any
 >a : any
 
@@ -24,7 +24,7 @@ trans(([b,c]) => 'foo');
 trans(({d: [e,f]}) => 'foo');
 >trans(({d: [e,f]}) => 'foo') : number
 >trans : <T>(f: (x: T) => string) => number
->({d: [e,f]}) => 'foo' : ({d: [e, f]}: { d: [any, any]; }) => string
+>({d: [e,f]}) => 'foo' : ({ d: [e, f] }: { d: [any, any]; }) => string
 >d : any
 >e : any
 >f : any
@@ -33,7 +33,7 @@ trans(({d: [e,f]}) => 'foo');
 trans(([{g},{h}]) => 'foo');
 >trans(([{g},{h}]) => 'foo') : number
 >trans : <T>(f: (x: T) => string) => number
->([{g},{h}]) => 'foo' : ([{g}, {h}]: [{ g: any; }, { h: any; }]) => string
+>([{g},{h}]) => 'foo' : ([{ g }, { h }]: [{ g: any; }, { h: any; }]) => string
 >g : any
 >h : any
 >'foo' : "foo"
@@ -41,7 +41,7 @@ trans(([{g},{h}]) => 'foo');
 trans(({a, b = 10}) => a);
 >trans(({a, b = 10}) => a) : number
 >trans : <T>(f: (x: T) => string) => number
->({a, b = 10}) => a : ({a, b}: { a: any; b?: number; }) => any
+>({a, b = 10}) => a : ({ a, b }: { a: any; b?: number; }) => any
 >a : any
 >b : number
 >10 : 10
diff --git a/tests/baselines/reference/noImplicitAnyDestructuringInPrivateMethod.types b/tests/baselines/reference/noImplicitAnyDestructuringInPrivateMethod.types
index a399e59e3c3..eb16207afed 100644
--- a/tests/baselines/reference/noImplicitAnyDestructuringInPrivateMethod.types
+++ b/tests/baselines/reference/noImplicitAnyDestructuringInPrivateMethod.types
@@ -10,7 +10,7 @@ export class Bar {
 >Bar : Bar
 
     private bar({ a, }: Arg): number {
->bar : ({a}: { a: number; }) => number
+>bar : ({ a, }: { a: number; }) => number
 >a : number
 >Arg : { a: number; }
 
@@ -22,6 +22,6 @@ export declare class Bar2 {
 >Bar2 : Bar2
 
     private bar({ a, });
->bar : ({a}: { a: any; }) => any
+>bar : ({ a, }: { a: any; }) => any
 >a : any
 }
diff --git a/tests/baselines/reference/objectRest.types b/tests/baselines/reference/objectRest.types
index 2fff9a3c729..dff8830e818 100644
--- a/tests/baselines/reference/objectRest.types
+++ b/tests/baselines/reference/objectRest.types
@@ -218,8 +218,8 @@ var { [computed]: stillNotGreat, [computed2]: soSo,  ...o } = o;
 >o : { a: number; b: string; }
 
 var noContextualType = ({ aNumber = 12, ...notEmptyObject }) => aNumber + notEmptyObject.anythingGoes;
->noContextualType : ({aNumber, ...notEmptyObject}: { [x: string]: any; aNumber?: number; }) => any
->({ aNumber = 12, ...notEmptyObject }) => aNumber + notEmptyObject.anythingGoes : ({aNumber, ...notEmptyObject}: { [x: string]: any; aNumber?: number; }) => any
+>noContextualType : ({ aNumber, ...notEmptyObject }: { [x: string]: any; aNumber?: number; }) => any
+>({ aNumber = 12, ...notEmptyObject }) => aNumber + notEmptyObject.anythingGoes : ({ aNumber, ...notEmptyObject }: { [x: string]: any; aNumber?: number; }) => any
 >aNumber : number
 >12 : 12
 >notEmptyObject : { [x: string]: any; }
diff --git a/tests/baselines/reference/objectRestParameter.types b/tests/baselines/reference/objectRestParameter.types
index e56e7cebfc7..3d0d1bb619b 100644
--- a/tests/baselines/reference/objectRestParameter.types
+++ b/tests/baselines/reference/objectRestParameter.types
@@ -1,6 +1,6 @@
 === tests/cases/conformance/types/rest/objectRestParameter.ts ===
 function cloneAgain({ a, ...clone }: { a: number, b: string }): void {
->cloneAgain : ({a, ...clone}: { a: number; b: string; }) => void
+>cloneAgain : ({ a, ...clone }: { a: number; b: string; }) => void
 >a : number
 >clone : { b: string; }
 >a : number
@@ -19,7 +19,7 @@ declare function suddenly(f: (a: { x: { z, ka }, y: string }) => void);
 suddenly(({ x: a, ...rest }) => rest.y);
 >suddenly(({ x: a, ...rest }) => rest.y) : any
 >suddenly : (f: (a: { x: { z: any; ka: any; }; y: string; }) => void) => any
->({ x: a, ...rest }) => rest.y : ({x: a, ...rest}: { x: { z: any; ka: any; }; y: string; }) => string
+>({ x: a, ...rest }) => rest.y : ({ x: a, ...rest }: { x: { z: any; ka: any; }; y: string; }) => string
 >x : any
 >a : { z: any; ka: any; }
 >rest : { y: string; }
@@ -30,7 +30,7 @@ suddenly(({ x: a, ...rest }) => rest.y);
 suddenly(({ x: { z = 12, ...nested }, ...rest } = { x: { z: 1, ka: 1 }, y: 'noo' }) => rest.y + nested.ka);
 >suddenly(({ x: { z = 12, ...nested }, ...rest } = { x: { z: 1, ka: 1 }, y: 'noo' }) => rest.y + nested.ka) : any
 >suddenly : (f: (a: { x: { z: any; ka: any; }; y: string; }) => void) => any
->({ x: { z = 12, ...nested }, ...rest } = { x: { z: 1, ka: 1 }, y: 'noo' }) => rest.y + nested.ka : ({x: {z, ...nested}, ...rest}?: { x: { z: any; ka: any; }; y: string; }) => string
+>({ x: { z = 12, ...nested }, ...rest } = { x: { z: 1, ka: 1 }, y: 'noo' }) => rest.y + nested.ka : ({ x: { z, ...nested }, ...rest }?: { x: { z: any; ka: any; }; y: string; }) => string
 >x : any
 >z : any
 >12 : 12
@@ -57,7 +57,7 @@ class C {
 >C : C
 
     m({ a, ...clone }: { a: number, b: string}): void {
->m : ({a, ...clone}: { a: number; b: string; }) => void
+>m : ({ a, ...clone }: { a: number; b: string; }) => void
 >a : number
 >clone : { b: string; }
 >a : number
@@ -76,7 +76,7 @@ class C {
     }
 }
 function foobar({ bar={}, ...opts }: any = {}) {
->foobar : ({bar, ...opts}?: any) => void
+>foobar : ({ bar, ...opts }?: any) => void
 >bar : {}
 >{} : {}
 >opts : any
@@ -84,18 +84,18 @@ function foobar({ bar={}, ...opts }: any = {}) {
 }
 foobar();
 >foobar() : void
->foobar : ({bar, ...opts}?: any) => void
+>foobar : ({ bar, ...opts }?: any) => void
 
 foobar({ baz: 'hello' });
 >foobar({ baz: 'hello' }) : void
->foobar : ({bar, ...opts}?: any) => void
+>foobar : ({ bar, ...opts }?: any) => void
 >{ baz: 'hello' } : { baz: string; }
 >baz : string
 >'hello' : "hello"
 
 foobar({ bar: { greeting: 'hello' } });
 >foobar({ bar: { greeting: 'hello' } }) : void
->foobar : ({bar, ...opts}?: any) => void
+>foobar : ({ bar, ...opts }?: any) => void
 >{ bar: { greeting: 'hello' } } : { bar: { greeting: string; }; }
 >bar : { greeting: string; }
 >{ greeting: 'hello' } : { greeting: string; }
diff --git a/tests/baselines/reference/objectRestParameterES5.types b/tests/baselines/reference/objectRestParameterES5.types
index 009d810782b..e0ebee39317 100644
--- a/tests/baselines/reference/objectRestParameterES5.types
+++ b/tests/baselines/reference/objectRestParameterES5.types
@@ -1,6 +1,6 @@
 === tests/cases/conformance/types/rest/objectRestParameterES5.ts ===
 function cloneAgain({ a, ...clone }: { a: number, b: string }): void {
->cloneAgain : ({a, ...clone}: { a: number; b: string; }) => void
+>cloneAgain : ({ a, ...clone }: { a: number; b: string; }) => void
 >a : number
 >clone : { b: string; }
 >a : number
@@ -19,7 +19,7 @@ declare function suddenly(f: (a: { x: { z, ka }, y: string }) => void);
 suddenly(({ x: a, ...rest }) => rest.y);
 >suddenly(({ x: a, ...rest }) => rest.y) : any
 >suddenly : (f: (a: { x: { z: any; ka: any; }; y: string; }) => void) => any
->({ x: a, ...rest }) => rest.y : ({x: a, ...rest}: { x: { z: any; ka: any; }; y: string; }) => string
+>({ x: a, ...rest }) => rest.y : ({ x: a, ...rest }: { x: { z: any; ka: any; }; y: string; }) => string
 >x : any
 >a : { z: any; ka: any; }
 >rest : { y: string; }
@@ -30,7 +30,7 @@ suddenly(({ x: a, ...rest }) => rest.y);
 suddenly(({ x: { z = 12, ...nested }, ...rest } = { x: { z: 1, ka: 1 }, y: 'noo' }) => rest.y + nested.ka);
 >suddenly(({ x: { z = 12, ...nested }, ...rest } = { x: { z: 1, ka: 1 }, y: 'noo' }) => rest.y + nested.ka) : any
 >suddenly : (f: (a: { x: { z: any; ka: any; }; y: string; }) => void) => any
->({ x: { z = 12, ...nested }, ...rest } = { x: { z: 1, ka: 1 }, y: 'noo' }) => rest.y + nested.ka : ({x: {z, ...nested}, ...rest}?: { x: { z: any; ka: any; }; y: string; }) => string
+>({ x: { z = 12, ...nested }, ...rest } = { x: { z: 1, ka: 1 }, y: 'noo' }) => rest.y + nested.ka : ({ x: { z, ...nested }, ...rest }?: { x: { z: any; ka: any; }; y: string; }) => string
 >x : any
 >z : any
 >12 : 12
@@ -57,7 +57,7 @@ class C {
 >C : C
 
     m({ a, ...clone }: { a: number, b: string}): void {
->m : ({a, ...clone}: { a: number; b: string; }) => void
+>m : ({ a, ...clone }: { a: number; b: string; }) => void
 >a : number
 >clone : { b: string; }
 >a : number
@@ -76,7 +76,7 @@ class C {
     }
 }
 function foobar({ bar={}, ...opts }: any = {}) {
->foobar : ({bar, ...opts}?: any) => void
+>foobar : ({ bar, ...opts }?: any) => void
 >bar : {}
 >{} : {}
 >opts : any
@@ -84,18 +84,18 @@ function foobar({ bar={}, ...opts }: any = {}) {
 }
 foobar();
 >foobar() : void
->foobar : ({bar, ...opts}?: any) => void
+>foobar : ({ bar, ...opts }?: any) => void
 
 foobar({ baz: 'hello' });
 >foobar({ baz: 'hello' }) : void
->foobar : ({bar, ...opts}?: any) => void
+>foobar : ({ bar, ...opts }?: any) => void
 >{ baz: 'hello' } : { baz: string; }
 >baz : string
 >'hello' : "hello"
 
 foobar({ bar: { greeting: 'hello' } });
 >foobar({ bar: { greeting: 'hello' } }) : void
->foobar : ({bar, ...opts}?: any) => void
+>foobar : ({ bar, ...opts }?: any) => void
 >{ bar: { greeting: 'hello' } } : { bar: { greeting: string; }; }
 >bar : { greeting: string; }
 >{ greeting: 'hello' } : { greeting: string; }
diff --git a/tests/baselines/reference/parameterInitializerBeforeDestructuringEmit.types b/tests/baselines/reference/parameterInitializerBeforeDestructuringEmit.types
index 46b5983a514..d276812c01d 100644
--- a/tests/baselines/reference/parameterInitializerBeforeDestructuringEmit.types
+++ b/tests/baselines/reference/parameterInitializerBeforeDestructuringEmit.types
@@ -10,7 +10,7 @@ interface Foo {
 }
 
 function foobar({ bar = {}, ...opts }: Foo = {}) {
->foobar : ({bar, ...opts}?: Foo) => void
+>foobar : ({ bar, ...opts }?: Foo) => void
 >bar : any
 >{} : {}
 >opts : { baz?: any; }
diff --git a/tests/baselines/reference/sourceMapValidationDestructuringParameterNestedObjectBindingPattern.types b/tests/baselines/reference/sourceMapValidationDestructuringParameterNestedObjectBindingPattern.types
index eef87d57c45..bbd13dddf57 100644
--- a/tests/baselines/reference/sourceMapValidationDestructuringParameterNestedObjectBindingPattern.types
+++ b/tests/baselines/reference/sourceMapValidationDestructuringParameterNestedObjectBindingPattern.types
@@ -37,7 +37,7 @@ var robotA: Robot = { name: "mower", skills: { primary: "mowing", secondary: "no
 >"none" : "none"
 
 function foo1({ skills: { primary: primaryA, secondary: secondaryA } }: Robot) {
->foo1 : ({skills: {primary: primaryA, secondary: secondaryA}}: Robot) => void
+>foo1 : ({ skills: { primary: primaryA, secondary: secondaryA } }: Robot) => void
 >skills : any
 >primary : any
 >primaryA : string
@@ -53,7 +53,7 @@ function foo1({ skills: { primary: primaryA, secondary: secondaryA } }: Robot) {
 >primaryA : string
 }
 function foo2({ name: nameC, skills: { primary: primaryB, secondary: secondaryB } }: Robot) {
->foo2 : ({name: nameC, skills: {primary: primaryB, secondary: secondaryB}}: Robot) => void
+>foo2 : ({ name: nameC, skills: { primary: primaryB, secondary: secondaryB } }: Robot) => void
 >name : any
 >nameC : string
 >skills : any
@@ -71,7 +71,7 @@ function foo2({ name: nameC, skills: { primary: primaryB, secondary: secondaryB
 >secondaryB : string
 }
 function foo3({ skills }: Robot) {
->foo3 : ({skills}: Robot) => void
+>foo3 : ({ skills }: Robot) => void
 >skills : { primary: string; secondary: string; }
 >Robot : Robot
 
@@ -87,12 +87,12 @@ function foo3({ skills }: Robot) {
 
 foo1(robotA);
 >foo1(robotA) : void
->foo1 : ({skills: {primary: primaryA, secondary: secondaryA}}: Robot) => void
+>foo1 : ({ skills: { primary: primaryA, secondary: secondaryA } }: Robot) => void
 >robotA : Robot
 
 foo1({ name: "Edger", skills: { primary: "edging", secondary: "branch trimming" } });
 >foo1({ name: "Edger", skills: { primary: "edging", secondary: "branch trimming" } }) : void
->foo1 : ({skills: {primary: primaryA, secondary: secondaryA}}: Robot) => void
+>foo1 : ({ skills: { primary: primaryA, secondary: secondaryA } }: Robot) => void
 >{ name: "Edger", skills: { primary: "edging", secondary: "branch trimming" } } : { name: string; skills: { primary: string; secondary: string; }; }
 >name : string
 >"Edger" : "Edger"
@@ -105,12 +105,12 @@ foo1({ name: "Edger", skills: { primary: "edging", secondary: "branch trimming"
 
 foo2(robotA);
 >foo2(robotA) : void
->foo2 : ({name: nameC, skills: {primary: primaryB, secondary: secondaryB}}: Robot) => void
+>foo2 : ({ name: nameC, skills: { primary: primaryB, secondary: secondaryB } }: Robot) => void
 >robotA : Robot
 
 foo2({ name: "Edger", skills: { primary: "edging", secondary: "branch trimming" } });
 >foo2({ name: "Edger", skills: { primary: "edging", secondary: "branch trimming" } }) : void
->foo2 : ({name: nameC, skills: {primary: primaryB, secondary: secondaryB}}: Robot) => void
+>foo2 : ({ name: nameC, skills: { primary: primaryB, secondary: secondaryB } }: Robot) => void
 >{ name: "Edger", skills: { primary: "edging", secondary: "branch trimming" } } : { name: string; skills: { primary: string; secondary: string; }; }
 >name : string
 >"Edger" : "Edger"
@@ -123,12 +123,12 @@ foo2({ name: "Edger", skills: { primary: "edging", secondary: "branch trimming"
 
 foo3(robotA);
 >foo3(robotA) : void
->foo3 : ({skills}: Robot) => void
+>foo3 : ({ skills }: Robot) => void
 >robotA : Robot
 
 foo3({ name: "Edger", skills: { primary: "edging", secondary: "branch trimming" } });
 >foo3({ name: "Edger", skills: { primary: "edging", secondary: "branch trimming" } }) : void
->foo3 : ({skills}: Robot) => void
+>foo3 : ({ skills }: Robot) => void
 >{ name: "Edger", skills: { primary: "edging", secondary: "branch trimming" } } : { name: string; skills: { primary: string; secondary: string; }; }
 >name : string
 >"Edger" : "Edger"
diff --git a/tests/baselines/reference/sourceMapValidationDestructuringParameterNestedObjectBindingPatternDefaultValues.types b/tests/baselines/reference/sourceMapValidationDestructuringParameterNestedObjectBindingPatternDefaultValues.types
index 9f5b16407ca..d9c8b319752 100644
--- a/tests/baselines/reference/sourceMapValidationDestructuringParameterNestedObjectBindingPatternDefaultValues.types
+++ b/tests/baselines/reference/sourceMapValidationDestructuringParameterNestedObjectBindingPatternDefaultValues.types
@@ -37,7 +37,7 @@ var robotA: Robot = { name: "mower", skills: { primary: "mowing", secondary: "no
 >"none" : "none"
 
 function foo1(
->foo1 : ({skills: {primary: primaryA, secondary: secondaryA}}?: Robot) => void
+>foo1 : ({ skills: { primary: primaryA, secondary: secondaryA } }?: Robot) => void
     {
         skills: {
 >skills : any
@@ -71,7 +71,7 @@ function foo1(
 >primaryA : string
 }
 function foo2(
->foo2 : ({name: nameC, skills: {primary: primaryB, secondary: secondaryB}}?: Robot) => void
+>foo2 : ({ name: nameC, skills: { primary: primaryB, secondary: secondaryB } }?: Robot) => void
     {
         name: nameC = "name",
 >name : any
@@ -110,7 +110,7 @@ function foo2(
 >secondaryB : string
 }
 function foo3({ skills = { primary: "SomeSkill", secondary: "someSkill" }  }: Robot = robotA) {
->foo3 : ({skills}?: Robot) => void
+>foo3 : ({ skills }?: Robot) => void
 >skills : { primary?: string; secondary?: string; }
 >{ primary: "SomeSkill", secondary: "someSkill" } : { primary: string; secondary: string; }
 >primary : string
@@ -132,12 +132,12 @@ function foo3({ skills = { primary: "SomeSkill", secondary: "someSkill" }  }: Ro
 
 foo1(robotA);
 >foo1(robotA) : void
->foo1 : ({skills: {primary: primaryA, secondary: secondaryA}}?: Robot) => void
+>foo1 : ({ skills: { primary: primaryA, secondary: secondaryA } }?: Robot) => void
 >robotA : Robot
 
 foo1({ name: "Edger", skills: { primary: "edging", secondary: "branch trimming" } });
 >foo1({ name: "Edger", skills: { primary: "edging", secondary: "branch trimming" } }) : void
->foo1 : ({skills: {primary: primaryA, secondary: secondaryA}}?: Robot) => void
+>foo1 : ({ skills: { primary: primaryA, secondary: secondaryA } }?: Robot) => void
 >{ name: "Edger", skills: { primary: "edging", secondary: "branch trimming" } } : { name: string; skills: { primary: string; secondary: string; }; }
 >name : string
 >"Edger" : "Edger"
@@ -150,12 +150,12 @@ foo1({ name: "Edger", skills: { primary: "edging", secondary: "branch trimming"
 
 foo2(robotA);
 >foo2(robotA) : void
->foo2 : ({name: nameC, skills: {primary: primaryB, secondary: secondaryB}}?: Robot) => void
+>foo2 : ({ name: nameC, skills: { primary: primaryB, secondary: secondaryB } }?: Robot) => void
 >robotA : Robot
 
 foo2({ name: "Edger", skills: { primary: "edging", secondary: "branch trimming" } });
 >foo2({ name: "Edger", skills: { primary: "edging", secondary: "branch trimming" } }) : void
->foo2 : ({name: nameC, skills: {primary: primaryB, secondary: secondaryB}}?: Robot) => void
+>foo2 : ({ name: nameC, skills: { primary: primaryB, secondary: secondaryB } }?: Robot) => void
 >{ name: "Edger", skills: { primary: "edging", secondary: "branch trimming" } } : { name: string; skills: { primary: string; secondary: string; }; }
 >name : string
 >"Edger" : "Edger"
@@ -168,12 +168,12 @@ foo2({ name: "Edger", skills: { primary: "edging", secondary: "branch trimming"
 
 foo3(robotA);
 >foo3(robotA) : void
->foo3 : ({skills}?: Robot) => void
+>foo3 : ({ skills }?: Robot) => void
 >robotA : Robot
 
 foo3({ name: "Edger", skills: { primary: "edging", secondary: "branch trimming" } });
 >foo3({ name: "Edger", skills: { primary: "edging", secondary: "branch trimming" } }) : void
->foo3 : ({skills}?: Robot) => void
+>foo3 : ({ skills }?: Robot) => void
 >{ name: "Edger", skills: { primary: "edging", secondary: "branch trimming" } } : { name: string; skills: { primary: string; secondary: string; }; }
 >name : string
 >"Edger" : "Edger"
diff --git a/tests/baselines/reference/sourceMapValidationDestructuringParameterObjectBindingPattern.types b/tests/baselines/reference/sourceMapValidationDestructuringParameterObjectBindingPattern.types
index 225071a3d2e..5185ab35994 100644
--- a/tests/baselines/reference/sourceMapValidationDestructuringParameterObjectBindingPattern.types
+++ b/tests/baselines/reference/sourceMapValidationDestructuringParameterObjectBindingPattern.types
@@ -29,7 +29,7 @@ var robotA: Robot = { name: "mower", skill: "mowing" };
 >"mowing" : "mowing"
 
 function foo1({ name: nameA }: Robot) {
->foo1 : ({name: nameA}: Robot) => void
+>foo1 : ({ name: nameA }: Robot) => void
 >name : any
 >nameA : string
 >Robot : Robot
@@ -42,7 +42,7 @@ function foo1({ name: nameA }: Robot) {
 >nameA : string
 }
 function foo2({ name: nameB, skill: skillB }: Robot) {
->foo2 : ({name: nameB, skill: skillB}: Robot) => void
+>foo2 : ({ name: nameB, skill: skillB }: Robot) => void
 >name : any
 >nameB : string
 >skill : any
@@ -57,7 +57,7 @@ function foo2({ name: nameB, skill: skillB }: Robot) {
 >nameB : string
 }
 function foo3({ name }: Robot) {
->foo3 : ({name}: Robot) => void
+>foo3 : ({ name }: Robot) => void
 >name : string
 >Robot : Robot
 
@@ -71,12 +71,12 @@ function foo3({ name }: Robot) {
 
 foo1(robotA);
 >foo1(robotA) : void
->foo1 : ({name: nameA}: Robot) => void
+>foo1 : ({ name: nameA }: Robot) => void
 >robotA : Robot
 
 foo1({ name: "Edger", skill: "cutting edges" });
 >foo1({ name: "Edger", skill: "cutting edges" }) : void
->foo1 : ({name: nameA}: Robot) => void
+>foo1 : ({ name: nameA }: Robot) => void
 >{ name: "Edger", skill: "cutting edges" } : { name: string; skill: string; }
 >name : string
 >"Edger" : "Edger"
@@ -85,12 +85,12 @@ foo1({ name: "Edger", skill: "cutting edges" });
 
 foo2(robotA);
 >foo2(robotA) : void
->foo2 : ({name: nameB, skill: skillB}: Robot) => void
+>foo2 : ({ name: nameB, skill: skillB }: Robot) => void
 >robotA : Robot
 
 foo2({ name: "Edger", skill: "cutting edges" });
 >foo2({ name: "Edger", skill: "cutting edges" }) : void
->foo2 : ({name: nameB, skill: skillB}: Robot) => void
+>foo2 : ({ name: nameB, skill: skillB }: Robot) => void
 >{ name: "Edger", skill: "cutting edges" } : { name: string; skill: string; }
 >name : string
 >"Edger" : "Edger"
@@ -99,12 +99,12 @@ foo2({ name: "Edger", skill: "cutting edges" });
 
 foo3(robotA);
 >foo3(robotA) : void
->foo3 : ({name}: Robot) => void
+>foo3 : ({ name }: Robot) => void
 >robotA : Robot
 
 foo3({ name: "Edger", skill: "cutting edges" });
 >foo3({ name: "Edger", skill: "cutting edges" }) : void
->foo3 : ({name}: Robot) => void
+>foo3 : ({ name }: Robot) => void
 >{ name: "Edger", skill: "cutting edges" } : { name: string; skill: string; }
 >name : string
 >"Edger" : "Edger"
diff --git a/tests/baselines/reference/sourceMapValidationDestructuringParameterObjectBindingPatternDefaultValues.types b/tests/baselines/reference/sourceMapValidationDestructuringParameterObjectBindingPatternDefaultValues.types
index db6a8bcab29..ca6670e5561 100644
--- a/tests/baselines/reference/sourceMapValidationDestructuringParameterObjectBindingPatternDefaultValues.types
+++ b/tests/baselines/reference/sourceMapValidationDestructuringParameterObjectBindingPatternDefaultValues.types
@@ -29,7 +29,7 @@ var robotA: Robot = { name: "mower", skill: "mowing" };
 >"mowing" : "mowing"
 
 function foo1({ name: nameA = "<NoName>" }: Robot = { }) {
->foo1 : ({name: nameA}?: Robot) => void
+>foo1 : ({ name: nameA }?: Robot) => void
 >name : any
 >nameA : string
 >"<NoName>" : "<NoName>"
@@ -44,7 +44,7 @@ function foo1({ name: nameA = "<NoName>" }: Robot = { }) {
 >nameA : string
 }
 function foo2({ name: nameB = "<NoName>", skill: skillB = "noSkill" }: Robot = {}) {
->foo2 : ({name: nameB, skill: skillB}?: Robot) => void
+>foo2 : ({ name: nameB, skill: skillB }?: Robot) => void
 >name : any
 >nameB : string
 >"<NoName>" : "<NoName>"
@@ -62,7 +62,7 @@ function foo2({ name: nameB = "<NoName>", skill: skillB = "noSkill" }: Robot = {
 >nameB : string
 }
 function foo3({ name = "<NoName>" }: Robot = {}) {
->foo3 : ({name}?: Robot) => void
+>foo3 : ({ name }?: Robot) => void
 >name : string
 >"<NoName>" : "<NoName>"
 >Robot : Robot
@@ -78,12 +78,12 @@ function foo3({ name = "<NoName>" }: Robot = {}) {
 
 foo1(robotA);
 >foo1(robotA) : void
->foo1 : ({name: nameA}?: Robot) => void
+>foo1 : ({ name: nameA }?: Robot) => void
 >robotA : Robot
 
 foo1({ name: "Edger", skill: "cutting edges" });
 >foo1({ name: "Edger", skill: "cutting edges" }) : void
->foo1 : ({name: nameA}?: Robot) => void
+>foo1 : ({ name: nameA }?: Robot) => void
 >{ name: "Edger", skill: "cutting edges" } : { name: string; skill: string; }
 >name : string
 >"Edger" : "Edger"
@@ -92,12 +92,12 @@ foo1({ name: "Edger", skill: "cutting edges" });
 
 foo2(robotA);
 >foo2(robotA) : void
->foo2 : ({name: nameB, skill: skillB}?: Robot) => void
+>foo2 : ({ name: nameB, skill: skillB }?: Robot) => void
 >robotA : Robot
 
 foo2({ name: "Edger", skill: "cutting edges" });
 >foo2({ name: "Edger", skill: "cutting edges" }) : void
->foo2 : ({name: nameB, skill: skillB}?: Robot) => void
+>foo2 : ({ name: nameB, skill: skillB }?: Robot) => void
 >{ name: "Edger", skill: "cutting edges" } : { name: string; skill: string; }
 >name : string
 >"Edger" : "Edger"
@@ -106,12 +106,12 @@ foo2({ name: "Edger", skill: "cutting edges" });
 
 foo3(robotA);
 >foo3(robotA) : void
->foo3 : ({name}?: Robot) => void
+>foo3 : ({ name }?: Robot) => void
 >robotA : Robot
 
 foo3({ name: "Edger", skill: "cutting edges" });
 >foo3({ name: "Edger", skill: "cutting edges" }) : void
->foo3 : ({name}?: Robot) => void
+>foo3 : ({ name }?: Robot) => void
 >{ name: "Edger", skill: "cutting edges" } : { name: string; skill: string; }
 >name : string
 >"Edger" : "Edger"
diff --git a/tests/baselines/reference/tsxSpreadAttributesResolution13.types b/tests/baselines/reference/tsxSpreadAttributesResolution13.types
index 5b5ada68613..0ad324c25b1 100644
--- a/tests/baselines/reference/tsxSpreadAttributesResolution13.types
+++ b/tests/baselines/reference/tsxSpreadAttributesResolution13.types
@@ -28,7 +28,7 @@ export default function Component(props: ComponentProps) {
 
             <ChildComponent {...props} />
 ><ChildComponent {...props} /> : JSX.Element
->ChildComponent : ({property1}: AnotherComponentProps) => JSX.Element
+>ChildComponent : ({ property1 }: AnotherComponentProps) => JSX.Element
 >props : ComponentProps
 
         );
@@ -37,7 +37,7 @@ export default function Component(props: ComponentProps) {
         return (<ChildComponent {...props} property1="NewString" />);
 >(<ChildComponent {...props} property1="NewString" />) : JSX.Element
 ><ChildComponent {...props} property1="NewString" /> : JSX.Element
->ChildComponent : ({property1}: AnotherComponentProps) => JSX.Element
+>ChildComponent : ({ property1 }: AnotherComponentProps) => JSX.Element
 >props : ComponentProps
 >property1 : string
     }
@@ -51,7 +51,7 @@ interface AnotherComponentProps {
 }
 
 function ChildComponent({ property1 }: AnotherComponentProps) {
->ChildComponent : ({property1}: AnotherComponentProps) => JSX.Element
+>ChildComponent : ({ property1 }: AnotherComponentProps) => JSX.Element
 >property1 : string
 >AnotherComponentProps : AnotherComponentProps
 
diff --git a/tests/baselines/reference/tsxSpreadAttributesResolution15.types b/tests/baselines/reference/tsxSpreadAttributesResolution15.types
index dbcb6541a03..152ad3f696e 100644
--- a/tests/baselines/reference/tsxSpreadAttributesResolution15.types
+++ b/tests/baselines/reference/tsxSpreadAttributesResolution15.types
@@ -22,7 +22,7 @@ export default function Component(props: ComponentProps) {
 
         <AnotherComponent {...props} property2 AnotherProperty1="hi"/>
 ><AnotherComponent {...props} property2 AnotherProperty1="hi"/> : JSX.Element
->AnotherComponent : ({property1}: AnotherComponentProps) => JSX.Element
+>AnotherComponent : ({ property1 }: AnotherComponentProps) => JSX.Element
 >props : ComponentProps
 >property2 : true
 >AnotherProperty1 : string
@@ -44,7 +44,7 @@ interface AnotherComponentProps {
 }
 
 function AnotherComponent({ property1 }: AnotherComponentProps) {
->AnotherComponent : ({property1}: AnotherComponentProps) => JSX.Element
+>AnotherComponent : ({ property1 }: AnotherComponentProps) => JSX.Element
 >property1 : string
 >AnotherComponentProps : AnotherComponentProps
 
diff --git a/tests/baselines/reference/tsxSpreadChildren.types b/tests/baselines/reference/tsxSpreadChildren.types
index 7f4609c30b8..c762e45b593 100644
--- a/tests/baselines/reference/tsxSpreadChildren.types
+++ b/tests/baselines/reference/tsxSpreadChildren.types
@@ -53,7 +53,7 @@ function Todo(prop: { key: number, todo: string }) {
 >div : any
 }
 function TodoList({ todos }: TodoListProps) {
->TodoList : ({todos}: TodoListProps) => JSX.Element
+>TodoList : ({ todos }: TodoListProps) => JSX.Element
 >todos : TodoProp[]
 >TodoListProps : TodoListProps
 
@@ -88,6 +88,6 @@ let x: TodoListProps;
 
     <TodoList {...x}/>
 ><TodoList {...x}/> : JSX.Element
->TodoList : ({todos}: TodoListProps) => JSX.Element
+>TodoList : ({ todos }: TodoListProps) => JSX.Element
 >x : TodoListProps
 
diff --git a/tests/baselines/reference/tsxStatelessFunctionComponentOverload1.types b/tests/baselines/reference/tsxStatelessFunctionComponentOverload1.types
index 8e288ebd34a..875f8018a95 100644
--- a/tests/baselines/reference/tsxStatelessFunctionComponentOverload1.types
+++ b/tests/baselines/reference/tsxStatelessFunctionComponentOverload1.types
@@ -79,21 +79,21 @@ const c5 = <OneThing yxx1='ok'>Hello</OneThing>
 
 
 declare function TestingOneThing({y1: string}): JSX.Element;
->TestingOneThing : { ({y1: string}: { y1: any; }): JSX.Element; (j: { "extra-data": string; yy?: string; }): JSX.Element; (n: { yy: number; direction?: number; }): JSX.Element; (n: { yy: string; name: string; }): JSX.Element; }
+>TestingOneThing : { ({ y1: string }: { y1: any; }): JSX.Element; (j: { "extra-data": string; yy?: string; }): JSX.Element; (n: { yy: number; direction?: number; }): JSX.Element; (n: { yy: string; name: string; }): JSX.Element; }
 >y1 : any
 >string : any
 >JSX : any
 >Element : JSX.Element
 
 declare function TestingOneThing(j: {"extra-data": string, yy?: string}): JSX.Element;
->TestingOneThing : { ({y1: string}: { y1: any; }): JSX.Element; (j: { "extra-data": string; yy?: string; }): JSX.Element; (n: { yy: number; direction?: number; }): JSX.Element; (n: { yy: string; name: string; }): JSX.Element; }
+>TestingOneThing : { ({ y1: string }: { y1: any; }): JSX.Element; (j: { "extra-data": string; yy?: string; }): JSX.Element; (n: { yy: number; direction?: number; }): JSX.Element; (n: { yy: string; name: string; }): JSX.Element; }
 >j : { "extra-data": string; yy?: string; }
 >yy : string
 >JSX : any
 >Element : JSX.Element
 
 declare function TestingOneThing(n: {yy: number, direction?: number}): JSX.Element;
->TestingOneThing : { ({y1: string}: { y1: any; }): JSX.Element; (j: { "extra-data": string; yy?: string; }): JSX.Element; (n: { yy: number; direction?: number; }): JSX.Element; (n: { yy: string; name: string; }): JSX.Element; }
+>TestingOneThing : { ({ y1: string }: { y1: any; }): JSX.Element; (j: { "extra-data": string; yy?: string; }): JSX.Element; (n: { yy: number; direction?: number; }): JSX.Element; (n: { yy: string; name: string; }): JSX.Element; }
 >n : { yy: number; direction?: number; }
 >yy : number
 >direction : number
@@ -101,7 +101,7 @@ declare function TestingOneThing(n: {yy: number, direction?: number}): JSX.Eleme
 >Element : JSX.Element
 
 declare function TestingOneThing(n: {yy: string, name: string}): JSX.Element;
->TestingOneThing : { ({y1: string}: { y1: any; }): JSX.Element; (j: { "extra-data": string; yy?: string; }): JSX.Element; (n: { yy: number; direction?: number; }): JSX.Element; (n: { yy: string; name: string; }): JSX.Element; }
+>TestingOneThing : { ({ y1: string }: { y1: any; }): JSX.Element; (j: { "extra-data": string; yy?: string; }): JSX.Element; (n: { yy: number; direction?: number; }): JSX.Element; (n: { yy: string; name: string; }): JSX.Element; }
 >n : { yy: string; name: string; }
 >yy : string
 >name : string
@@ -112,27 +112,27 @@ declare function TestingOneThing(n: {yy: string, name: string}): JSX.Element;
 const d1 = <TestingOneThing y1 extra-data />;
 >d1 : JSX.Element
 ><TestingOneThing y1 extra-data /> : JSX.Element
->TestingOneThing : { ({y1: string}: { y1: any; }): JSX.Element; (j: { "extra-data": string; yy?: string; }): JSX.Element; (n: { yy: number; direction?: number; }): JSX.Element; (n: { yy: string; name: string; }): JSX.Element; }
+>TestingOneThing : { ({ y1: string }: { y1: any; }): JSX.Element; (j: { "extra-data": string; yy?: string; }): JSX.Element; (n: { yy: number; direction?: number; }): JSX.Element; (n: { yy: string; name: string; }): JSX.Element; }
 >y1 : true
 >extra-data : true
 
 const d2 = <TestingOneThing extra-data="hello" />;
 >d2 : JSX.Element
 ><TestingOneThing extra-data="hello" /> : JSX.Element
->TestingOneThing : { ({y1: string}: { y1: any; }): JSX.Element; (j: { "extra-data": string; yy?: string; }): JSX.Element; (n: { yy: number; direction?: number; }): JSX.Element; (n: { yy: string; name: string; }): JSX.Element; }
+>TestingOneThing : { ({ y1: string }: { y1: any; }): JSX.Element; (j: { "extra-data": string; yy?: string; }): JSX.Element; (n: { yy: number; direction?: number; }): JSX.Element; (n: { yy: string; name: string; }): JSX.Element; }
 >extra-data : string
 
 const d3 = <TestingOneThing extra-data="hello" yy="hihi" />;
 >d3 : JSX.Element
 ><TestingOneThing extra-data="hello" yy="hihi" /> : JSX.Element
->TestingOneThing : { ({y1: string}: { y1: any; }): JSX.Element; (j: { "extra-data": string; yy?: string; }): JSX.Element; (n: { yy: number; direction?: number; }): JSX.Element; (n: { yy: string; name: string; }): JSX.Element; }
+>TestingOneThing : { ({ y1: string }: { y1: any; }): JSX.Element; (j: { "extra-data": string; yy?: string; }): JSX.Element; (n: { yy: number; direction?: number; }): JSX.Element; (n: { yy: string; name: string; }): JSX.Element; }
 >extra-data : string
 >yy : string
 
 const d4 = <TestingOneThing extra-data="hello" yy={9} direction={10} />;
 >d4 : JSX.Element
 ><TestingOneThing extra-data="hello" yy={9} direction={10} /> : JSX.Element
->TestingOneThing : { ({y1: string}: { y1: any; }): JSX.Element; (j: { "extra-data": string; yy?: string; }): JSX.Element; (n: { yy: number; direction?: number; }): JSX.Element; (n: { yy: string; name: string; }): JSX.Element; }
+>TestingOneThing : { ({ y1: string }: { y1: any; }): JSX.Element; (j: { "extra-data": string; yy?: string; }): JSX.Element; (n: { yy: number; direction?: number; }): JSX.Element; (n: { yy: string; name: string; }): JSX.Element; }
 >extra-data : string
 >yy : number
 >9 : 9
@@ -142,7 +142,7 @@ const d4 = <TestingOneThing extra-data="hello" yy={9} direction={10} />;
 const d5 = <TestingOneThing extra-data="hello" yy="hello" name="Bob" />;
 >d5 : JSX.Element
 ><TestingOneThing extra-data="hello" yy="hello" name="Bob" /> : JSX.Element
->TestingOneThing : { ({y1: string}: { y1: any; }): JSX.Element; (j: { "extra-data": string; yy?: string; }): JSX.Element; (n: { yy: number; direction?: number; }): JSX.Element; (n: { yy: string; name: string; }): JSX.Element; }
+>TestingOneThing : { ({ y1: string }: { y1: any; }): JSX.Element; (j: { "extra-data": string; yy?: string; }): JSX.Element; (n: { yy: number; direction?: number; }): JSX.Element; (n: { yy: string; name: string; }): JSX.Element; }
 >extra-data : string
 >yy : string
 >name : string
diff --git a/tests/baselines/reference/tsxStatelessFunctionComponents3.types b/tests/baselines/reference/tsxStatelessFunctionComponents3.types
index 879f8c75cdf..e01c8454aa7 100644
--- a/tests/baselines/reference/tsxStatelessFunctionComponents3.types
+++ b/tests/baselines/reference/tsxStatelessFunctionComponents3.types
@@ -40,7 +40,7 @@ var App: React.StatelessComponent<{ children }> = ({children}) => (
 >React : any
 >StatelessComponent : React.StatelessComponent<P>
 >children : any
->({children}) => (    <div >        <MainMenu/>	</div>) : ({children}: { children: any; } & { children?: React.ReactNode; }) => JSX.Element
+>({children}) => (    <div >        <MainMenu/>	</div>) : ({ children }: { children: any; } & { children?: React.ReactNode; }) => JSX.Element
 >children : any
 >(    <div >        <MainMenu/>	</div>) : JSX.Element
 

From b40bc0c01954a4467a44fd406ce77300ffa45fdf Mon Sep 17 00:00:00 2001
From: Kanchalai Tanglertsampan <yuisu@microsoft.com>
Date: Tue, 23 May 2017 14:31:37 -0700
Subject: [PATCH 16/56] Add type alias for TypeReferenceType and convert to use
 JSDoc

---
 src/compiler/checker.ts | 30 ++++++++++++++++++------------
 src/compiler/types.ts   |  2 ++
 2 files changed, 20 insertions(+), 12 deletions(-)

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 07c20ad7aa0..7b084a0f261 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -6696,8 +6696,10 @@ namespace ts {
             return length(type.target.typeParameters);
         }
 
-        // Get type from reference to class or interface
-        function getTypeFromClassOrInterfaceReference(node: TypeReferenceNode | ExpressionWithTypeArguments | JSDocTypeReference, symbol: Symbol, typeArgs: Type[]): Type {
+        /**
+         * Get type from type-reference that reference to class or interface
+         */
+        function getTypeFromClassOrInterfaceReference(node: TypeReferenceType, symbol: Symbol, typeArgs: Type[]): Type {
             const type = <InterfaceType>getDeclaredTypeOfSymbol(getMergedSymbol(symbol));
             const typeParameters = type.localTypeParameters;
             if (typeParameters) {
@@ -6738,10 +6740,12 @@ namespace ts {
             return instantiation;
         }
 
-        // Get type from reference to type alias. When a type alias is generic, the declared type of the type alias may include
-        // references to the type parameters of the alias. We replace those with the actual type arguments by instantiating the
-        // declared type. Instantiations are cached using the type identities of the type arguments as the key.
-        function getTypeFromTypeAliasReference(node: TypeReferenceNode | ExpressionWithTypeArguments | JSDocTypeReference, symbol: Symbol, typeArguments: Type[]): Type {
+        /**
+         * Get type from reference to type alias. When a type alias is generic, the declared type of the type alias may include
+         * references to the type parameters of the alias. We replace those with the actual type arguments by instantiating the
+         * declared type. Instantiations are cached using the type identities of the type arguments as the key.
+         */
+        function getTypeFromTypeAliasReference(node: TypeReferenceType, symbol: Symbol, typeArguments: Type[]): Type {
             const type = getDeclaredTypeOfSymbol(symbol);
             const typeParameters = getSymbolLinks(symbol).typeParameters;
             if (typeParameters) {
@@ -6766,8 +6770,10 @@ namespace ts {
             return type;
         }
 
-        // Get type from reference to named type that cannot be generic (enum or type parameter)
-        function getTypeFromNonGenericTypeReference(node: TypeReferenceNode | ExpressionWithTypeArguments | JSDocTypeReference, symbol: Symbol): Type {
+        /**
+         * Get type from reference to named type that cannot be generic (enum or type parameter)
+         */
+        function getTypeFromNonGenericTypeReference(node: TypeReferenceType, symbol: Symbol): Type {
             if (node.typeArguments) {
                 error(node, Diagnostics.Type_0_is_not_generic, symbolToString(symbol));
                 return unknownType;
@@ -6775,7 +6781,7 @@ namespace ts {
             return getDeclaredTypeOfSymbol(symbol);
         }
 
-        function getTypeReferenceName(node: TypeReferenceNode | ExpressionWithTypeArguments | JSDocTypeReference): EntityNameOrEntityNameExpression | undefined {
+        function getTypeReferenceName(node: TypeReferenceType): EntityNameOrEntityNameExpression | undefined {
             switch (node.kind) {
                 case SyntaxKind.TypeReference:
                     return (<TypeReferenceNode>node).typeName;
@@ -6803,7 +6809,7 @@ namespace ts {
             return resolveEntityName(typeReferenceName, SymbolFlags.Type) || unknownSymbol;
         }
 
-        function getTypeReferenceType(node: TypeReferenceNode | ExpressionWithTypeArguments | JSDocTypeReference, symbol: Symbol) {
+        function getTypeReferenceType(node: TypeReferenceType, symbol: Symbol) {
             const typeArguments = typeArgumentsFromTypeReferenceNode(node); // Do unconditionally so we mark type arguments as referenced.
 
             if (symbol === unknownSymbol) {
@@ -6862,7 +6868,7 @@ namespace ts {
             return strictNullChecks ? getUnionType([type, nullType]) : type;
         }
 
-        function getTypeFromTypeReference(node: TypeReferenceNode | ExpressionWithTypeArguments | JSDocTypeReference): Type {
+        function getTypeFromTypeReference(node: TypeReferenceType): Type {
             const links = getNodeLinks(node);
             if (!links.resolvedType) {
                 let symbol: Symbol;
@@ -6893,7 +6899,7 @@ namespace ts {
             return links.resolvedType;
         }
 
-        function typeArgumentsFromTypeReferenceNode(node: TypeReferenceNode | ExpressionWithTypeArguments | JSDocTypeReference): Type[] {
+        function typeArgumentsFromTypeReferenceNode(node: TypeReferenceType): Type[] {
             return map(node.typeArguments, getTypeFromTypeNode);
         }
 
diff --git a/src/compiler/types.ts b/src/compiler/types.ts
index a8da09a11c5..73a2e46be90 100644
--- a/src/compiler/types.ts
+++ b/src/compiler/types.ts
@@ -892,6 +892,8 @@ namespace ts {
         kind: SyntaxKind.ConstructorType;
     }
 
+    export type TypeReferenceType = TypeReferenceNode | ExpressionWithTypeArguments | JSDocTypeReference;
+
     export interface TypeReferenceNode extends TypeNode {
         kind: SyntaxKind.TypeReference;
         typeName: EntityName;

From 3d9a1babf78cc5115fe6b1c4295dd9c3de95ef5f Mon Sep 17 00:00:00 2001
From: Kanchalai Tanglertsampan <yuisu@microsoft.com>
Date: Tue, 23 May 2017 16:10:56 -0700
Subject: [PATCH 17/56] Return "Function for JSDocType {Function}

---
 src/compiler/checker.ts | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 7b084a0f261..2d95f69f417 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -2818,9 +2818,11 @@ namespace ts {
                 const parameterDeclaration = getDeclarationOfKind<ParameterDeclaration>(parameterSymbol, SyntaxKind.Parameter);
                 const modifiers = parameterDeclaration.modifiers && parameterDeclaration.modifiers.map(getSynthesizedClone);
                 const dotDotDotToken = isRestParameter(parameterDeclaration) ? createToken(SyntaxKind.DotDotDotToken) : undefined;
-                const name = parameterDeclaration.name.kind === SyntaxKind.Identifier ?
-                    setEmitFlags(getSynthesizedClone(parameterDeclaration.name), EmitFlags.NoAsciiEscaping) :
-                    cloneBindingName(parameterDeclaration.name);
+                const name = parameterDeclaration.name ?
+                    parameterDeclaration.name.kind === SyntaxKind.Identifier ?
+                        setEmitFlags(getSynthesizedClone(parameterDeclaration.name), EmitFlags.NoAsciiEscaping) :
+                        cloneBindingName(parameterDeclaration.name) :
+                    parameterSymbol.name;
                 const questionToken = isOptionalParameter(parameterDeclaration) ? createToken(SyntaxKind.QuestionToken) : undefined;
 
                 let parameterType = getTypeOfSymbol(parameterSymbol);
@@ -6852,7 +6854,7 @@ namespace ts {
                     case "Object":
                         return anyType;
                     case "Function":
-                        return anyFunctionType;
+                        return globalFunctionType;
                     case "Array":
                     case "array":
                         return !node.typeArguments || !node.typeArguments.length ? createArrayType(anyType) : undefined;

From 72e6678804f2342e4ee4f1c25173d36b14f89ea4 Mon Sep 17 00:00:00 2001
From: Kanchalai Tanglertsampan <yuisu@microsoft.com>
Date: Tue, 23 May 2017 16:11:13 -0700
Subject: [PATCH 18/56] Update baselines

---
 ...jsFileCompilationRestParamJsDocFunction.types | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/tests/baselines/reference/jsFileCompilationRestParamJsDocFunction.types b/tests/baselines/reference/jsFileCompilationRestParamJsDocFunction.types
index 66e3da3e67f..54bc7938689 100644
--- a/tests/baselines/reference/jsFileCompilationRestParamJsDocFunction.types
+++ b/tests/baselines/reference/jsFileCompilationRestParamJsDocFunction.types
@@ -10,8 +10,8 @@
  * @returns {*} Returns the result of `func`.
  */
 function apply(func, thisArg, args) {
->apply : (func: {}, thisArg: any, ...args: any[]) => any
->func : {}
+>apply : (func: Function, thisArg: any, ...args: any[]) => any
+>func : Function
 >thisArg : any
 >args : any[]
 
@@ -28,7 +28,7 @@ function apply(func, thisArg, args) {
 >0 : 0
 >func.call(thisArg) : any
 >func.call : (this: Function, thisArg: any, ...argArray: any[]) => any
->func : {}
+>func : Function
 >call : (this: Function, thisArg: any, ...argArray: any[]) => any
 >thisArg : any
 
@@ -36,7 +36,7 @@ function apply(func, thisArg, args) {
 >1 : 1
 >func.call(thisArg, args[0]) : any
 >func.call : (this: Function, thisArg: any, ...argArray: any[]) => any
->func : {}
+>func : Function
 >call : (this: Function, thisArg: any, ...argArray: any[]) => any
 >thisArg : any
 >args[0] : any
@@ -47,7 +47,7 @@ function apply(func, thisArg, args) {
 >2 : 2
 >func.call(thisArg, args[0], args[1]) : any
 >func.call : (this: Function, thisArg: any, ...argArray: any[]) => any
->func : {}
+>func : Function
 >call : (this: Function, thisArg: any, ...argArray: any[]) => any
 >thisArg : any
 >args[0] : any
@@ -61,7 +61,7 @@ function apply(func, thisArg, args) {
 >3 : 3
 >func.call(thisArg, args[0], args[1], args[2]) : any
 >func.call : (this: Function, thisArg: any, ...argArray: any[]) => any
->func : {}
+>func : Function
 >call : (this: Function, thisArg: any, ...argArray: any[]) => any
 >thisArg : any
 >args[0] : any
@@ -77,12 +77,12 @@ function apply(func, thisArg, args) {
     return func.apply(thisArg, args);
 >func.apply(thisArg, args) : any
 >func.apply : (this: Function, thisArg: any, argArray?: any) => any
->func : {}
+>func : Function
 >apply : (this: Function, thisArg: any, argArray?: any) => any
 >thisArg : any
 >args : any[]
 }
 
 export default apply;
->apply : (func: {}, thisArg: any, ...args: any[]) => any
+>apply : (func: Function, thisArg: any, ...args: any[]) => any
 

From bd422e3a524e1fb8c975e660e6a70cb8446a33a8 Mon Sep 17 00:00:00 2001
From: Kanchalai Tanglertsampan <yuisu@microsoft.com>
Date: Tue, 23 May 2017 16:11:23 -0700
Subject: [PATCH 19/56] Add tests and update baselines

---
 tests/baselines/reference/jsDocTypeTag1.js    | 584 +++++++++++++++++
 tests/baselines/reference/jsDocTypeTag2.js    | 598 ++++++++++++++++++
 tests/baselines/reference/jsDocTypes2.js      |  37 ++
 tests/baselines/reference/jsDocTypes2.symbols |  40 ++
 tests/baselines/reference/jsDocTypes2.types   |  59 ++
 .../reference/jsDocTypes3.errors.txt          |  21 +
 tests/baselines/reference/jsDocTypes3.js      |  24 +
 tests/cases/conformance/salsa/jsDocTypes2.ts  |  23 +
 tests/cases/conformance/salsa/jsDocTypes3.ts  |  16 +
 .../cases/fourslash/jsDocTypeTagQuickInfo1.ts |  43 ++
 .../cases/fourslash/jsDocTypeTagQuickInfo2.ts |  40 ++
 11 files changed, 1485 insertions(+)
 create mode 100644 tests/baselines/reference/jsDocTypeTag1.js
 create mode 100644 tests/baselines/reference/jsDocTypeTag2.js
 create mode 100644 tests/baselines/reference/jsDocTypes2.js
 create mode 100644 tests/baselines/reference/jsDocTypes2.symbols
 create mode 100644 tests/baselines/reference/jsDocTypes2.types
 create mode 100644 tests/baselines/reference/jsDocTypes3.errors.txt
 create mode 100644 tests/baselines/reference/jsDocTypes3.js
 create mode 100644 tests/cases/conformance/salsa/jsDocTypes2.ts
 create mode 100644 tests/cases/conformance/salsa/jsDocTypes3.ts
 create mode 100644 tests/cases/fourslash/jsDocTypeTagQuickInfo1.ts
 create mode 100644 tests/cases/fourslash/jsDocTypeTagQuickInfo2.ts

diff --git a/tests/baselines/reference/jsDocTypeTag1.js b/tests/baselines/reference/jsDocTypeTag1.js
new file mode 100644
index 00000000000..5dcabf2aa09
--- /dev/null
+++ b/tests/baselines/reference/jsDocTypeTag1.js
@@ -0,0 +1,584 @@
+[
+  {
+    "marker": {
+      "fileName": "/tests/cases/fourslash/jsDocTypeTag1.js",
+      "position": 26
+    },
+    "quickInfo": {
+      "kind": "var",
+      "kindModifiers": "",
+      "textSpan": {
+        "start": 26,
+        "length": 1
+      },
+      "displayParts": [
+        {
+          "text": "var",
+          "kind": "keyword"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "S",
+          "kind": "localName"
+        },
+        {
+          "text": ":",
+          "kind": "punctuation"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "string",
+          "kind": "keyword"
+        }
+      ],
+      "documentation": [],
+      "tags": []
+    }
+  },
+  {
+    "marker": {
+      "fileName": "/tests/cases/fourslash/jsDocTypeTag1.js",
+      "position": 55
+    },
+    "quickInfo": {
+      "kind": "var",
+      "kindModifiers": "",
+      "textSpan": {
+        "start": 55,
+        "length": 1
+      },
+      "displayParts": [
+        {
+          "text": "var",
+          "kind": "keyword"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "N",
+          "kind": "localName"
+        },
+        {
+          "text": ":",
+          "kind": "punctuation"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "number",
+          "kind": "keyword"
+        }
+      ],
+      "documentation": [],
+      "tags": []
+    }
+  },
+  {
+    "marker": {
+      "fileName": "/tests/cases/fourslash/jsDocTypeTag1.js",
+      "position": 85
+    },
+    "quickInfo": {
+      "kind": "var",
+      "kindModifiers": "",
+      "textSpan": {
+        "start": 85,
+        "length": 1
+      },
+      "displayParts": [
+        {
+          "text": "var",
+          "kind": "keyword"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "B",
+          "kind": "localName"
+        },
+        {
+          "text": ":",
+          "kind": "punctuation"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "boolean",
+          "kind": "keyword"
+        }
+      ],
+      "documentation": [],
+      "tags": []
+    }
+  },
+  {
+    "marker": {
+      "fileName": "/tests/cases/fourslash/jsDocTypeTag1.js",
+      "position": 112
+    },
+    "quickInfo": {
+      "kind": "var",
+      "kindModifiers": "",
+      "textSpan": {
+        "start": 112,
+        "length": 1
+      },
+      "displayParts": [
+        {
+          "text": "var",
+          "kind": "keyword"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "V",
+          "kind": "localName"
+        },
+        {
+          "text": ":",
+          "kind": "punctuation"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "void",
+          "kind": "keyword"
+        }
+      ],
+      "documentation": [],
+      "tags": []
+    }
+  },
+  {
+    "marker": {
+      "fileName": "/tests/cases/fourslash/jsDocTypeTag1.js",
+      "position": 144
+    },
+    "quickInfo": {
+      "kind": "var",
+      "kindModifiers": "",
+      "textSpan": {
+        "start": 144,
+        "length": 1
+      },
+      "displayParts": [
+        {
+          "text": "var",
+          "kind": "keyword"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "U",
+          "kind": "localName"
+        },
+        {
+          "text": ":",
+          "kind": "punctuation"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "undefined",
+          "kind": "keyword"
+        }
+      ],
+      "documentation": [],
+      "tags": []
+    }
+  },
+  {
+    "marker": {
+      "fileName": "/tests/cases/fourslash/jsDocTypeTag1.js",
+      "position": 171
+    },
+    "quickInfo": {
+      "kind": "var",
+      "kindModifiers": "",
+      "textSpan": {
+        "start": 171,
+        "length": 2
+      },
+      "displayParts": [
+        {
+          "text": "var",
+          "kind": "keyword"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "Nl",
+          "kind": "localName"
+        },
+        {
+          "text": ":",
+          "kind": "punctuation"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "null",
+          "kind": "keyword"
+        }
+      ],
+      "documentation": [],
+      "tags": []
+    }
+  },
+  {
+    "marker": {
+      "fileName": "/tests/cases/fourslash/jsDocTypeTag1.js",
+      "position": 200
+    },
+    "quickInfo": {
+      "kind": "var",
+      "kindModifiers": "",
+      "textSpan": {
+        "start": 200,
+        "length": 1
+      },
+      "displayParts": [
+        {
+          "text": "var",
+          "kind": "keyword"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "A",
+          "kind": "localName"
+        },
+        {
+          "text": ":",
+          "kind": "punctuation"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "any",
+          "kind": "keyword"
+        },
+        {
+          "text": "[",
+          "kind": "punctuation"
+        },
+        {
+          "text": "]",
+          "kind": "punctuation"
+        }
+      ],
+      "documentation": [],
+      "tags": []
+    }
+  },
+  {
+    "marker": {
+      "fileName": "/tests/cases/fourslash/jsDocTypeTag1.js",
+      "position": 230
+    },
+    "quickInfo": {
+      "kind": "var",
+      "kindModifiers": "",
+      "textSpan": {
+        "start": 230,
+        "length": 1
+      },
+      "displayParts": [
+        {
+          "text": "var",
+          "kind": "keyword"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "P",
+          "kind": "localName"
+        },
+        {
+          "text": ":",
+          "kind": "punctuation"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "Promise",
+          "kind": "interfaceName"
+        },
+        {
+          "text": "<",
+          "kind": "punctuation"
+        },
+        {
+          "text": "any",
+          "kind": "keyword"
+        },
+        {
+          "text": ">",
+          "kind": "punctuation"
+        }
+      ],
+      "documentation": [],
+      "tags": []
+    }
+  },
+  {
+    "marker": {
+      "fileName": "/tests/cases/fourslash/jsDocTypeTag1.js",
+      "position": 259
+    },
+    "quickInfo": {
+      "kind": "var",
+      "kindModifiers": "",
+      "textSpan": {
+        "start": 259,
+        "length": 3
+      },
+      "displayParts": [
+        {
+          "text": "var",
+          "kind": "keyword"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "Obj",
+          "kind": "localName"
+        },
+        {
+          "text": ":",
+          "kind": "punctuation"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "any",
+          "kind": "keyword"
+        }
+      ],
+      "documentation": [],
+      "tags": []
+    }
+  },
+  {
+    "marker": {
+      "fileName": "/tests/cases/fourslash/jsDocTypeTag1.js",
+      "position": 292
+    },
+    "quickInfo": {
+      "kind": "var",
+      "kindModifiers": "",
+      "textSpan": {
+        "start": 292,
+        "length": 4
+      },
+      "displayParts": [
+        {
+          "text": "var",
+          "kind": "keyword"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "Func",
+          "kind": "localName"
+        },
+        {
+          "text": ":",
+          "kind": "punctuation"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "Function",
+          "kind": "localName"
+        }
+      ],
+      "documentation": [],
+      "tags": []
+    }
+  },
+  {
+    "marker": {
+      "fileName": "/tests/cases/fourslash/jsDocTypeTag1.js",
+      "position": 319
+    },
+    "quickInfo": {
+      "kind": "var",
+      "kindModifiers": "",
+      "textSpan": {
+        "start": 319,
+        "length": 7
+      },
+      "displayParts": [
+        {
+          "text": "var",
+          "kind": "keyword"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "AnyType",
+          "kind": "localName"
+        },
+        {
+          "text": ":",
+          "kind": "punctuation"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "any",
+          "kind": "keyword"
+        }
+      ],
+      "documentation": [],
+      "tags": []
+    }
+  },
+  {
+    "marker": {
+      "fileName": "/tests/cases/fourslash/jsDocTypeTag1.js",
+      "position": 349
+    },
+    "quickInfo": {
+      "kind": "var",
+      "kindModifiers": "",
+      "textSpan": {
+        "start": 349,
+        "length": 5
+      },
+      "displayParts": [
+        {
+          "text": "var",
+          "kind": "keyword"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "QType",
+          "kind": "localName"
+        },
+        {
+          "text": ":",
+          "kind": "punctuation"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "any",
+          "kind": "keyword"
+        }
+      ],
+      "documentation": [],
+      "tags": []
+    }
+  },
+  {
+    "marker": {
+      "fileName": "/tests/cases/fourslash/jsDocTypeTag1.js",
+      "position": 389
+    },
+    "quickInfo": {
+      "kind": "var",
+      "kindModifiers": "",
+      "textSpan": {
+        "start": 389,
+        "length": 4
+      },
+      "displayParts": [
+        {
+          "text": "var",
+          "kind": "keyword"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "SOrN",
+          "kind": "localName"
+        },
+        {
+          "text": ":",
+          "kind": "punctuation"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "string",
+          "kind": "keyword"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "|",
+          "kind": "punctuation"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "number",
+          "kind": "keyword"
+        }
+      ],
+      "documentation": [],
+      "tags": []
+    }
+  }
+]
\ No newline at end of file
diff --git a/tests/baselines/reference/jsDocTypeTag2.js b/tests/baselines/reference/jsDocTypeTag2.js
new file mode 100644
index 00000000000..07535dcee08
--- /dev/null
+++ b/tests/baselines/reference/jsDocTypeTag2.js
@@ -0,0 +1,598 @@
+[
+  {
+    "marker": {
+      "fileName": "/tests/cases/fourslash/jsDocTypeTag2.js",
+      "position": 26
+    },
+    "quickInfo": {
+      "kind": "var",
+      "kindModifiers": "",
+      "textSpan": {
+        "start": 26,
+        "length": 1
+      },
+      "displayParts": [
+        {
+          "text": "var",
+          "kind": "keyword"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "s",
+          "kind": "localName"
+        },
+        {
+          "text": ":",
+          "kind": "punctuation"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "string",
+          "kind": "keyword"
+        }
+      ],
+      "documentation": [],
+      "tags": []
+    }
+  },
+  {
+    "marker": {
+      "fileName": "/tests/cases/fourslash/jsDocTypeTag2.js",
+      "position": 55
+    },
+    "quickInfo": {
+      "kind": "var",
+      "kindModifiers": "",
+      "textSpan": {
+        "start": 55,
+        "length": 1
+      },
+      "displayParts": [
+        {
+          "text": "var",
+          "kind": "keyword"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "n",
+          "kind": "localName"
+        },
+        {
+          "text": ":",
+          "kind": "punctuation"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "number",
+          "kind": "keyword"
+        }
+      ],
+      "documentation": [],
+      "tags": []
+    }
+  },
+  {
+    "marker": {
+      "fileName": "/tests/cases/fourslash/jsDocTypeTag2.js",
+      "position": 85
+    },
+    "quickInfo": {
+      "kind": "var",
+      "kindModifiers": "",
+      "textSpan": {
+        "start": 85,
+        "length": 1
+      },
+      "displayParts": [
+        {
+          "text": "var",
+          "kind": "keyword"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "b",
+          "kind": "localName"
+        },
+        {
+          "text": ":",
+          "kind": "punctuation"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "boolean",
+          "kind": "keyword"
+        }
+      ],
+      "documentation": [],
+      "tags": []
+    }
+  },
+  {
+    "marker": {
+      "fileName": "/tests/cases/fourslash/jsDocTypeTag2.js",
+      "position": 112
+    },
+    "quickInfo": {
+      "kind": "var",
+      "kindModifiers": "",
+      "textSpan": {
+        "start": 112,
+        "length": 1
+      },
+      "displayParts": [
+        {
+          "text": "var",
+          "kind": "keyword"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "v",
+          "kind": "localName"
+        },
+        {
+          "text": ":",
+          "kind": "punctuation"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "void",
+          "kind": "keyword"
+        }
+      ],
+      "documentation": [],
+      "tags": []
+    }
+  },
+  {
+    "marker": {
+      "fileName": "/tests/cases/fourslash/jsDocTypeTag2.js",
+      "position": 144
+    },
+    "quickInfo": {
+      "kind": "var",
+      "kindModifiers": "",
+      "textSpan": {
+        "start": 144,
+        "length": 1
+      },
+      "displayParts": [
+        {
+          "text": "var",
+          "kind": "keyword"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "u",
+          "kind": "localName"
+        },
+        {
+          "text": ":",
+          "kind": "punctuation"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "undefined",
+          "kind": "keyword"
+        }
+      ],
+      "documentation": [],
+      "tags": []
+    }
+  },
+  {
+    "marker": {
+      "fileName": "/tests/cases/fourslash/jsDocTypeTag2.js",
+      "position": 171
+    },
+    "quickInfo": {
+      "kind": "var",
+      "kindModifiers": "",
+      "textSpan": {
+        "start": 171,
+        "length": 2
+      },
+      "displayParts": [
+        {
+          "text": "var",
+          "kind": "keyword"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "nl",
+          "kind": "localName"
+        },
+        {
+          "text": ":",
+          "kind": "punctuation"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "null",
+          "kind": "keyword"
+        }
+      ],
+      "documentation": [],
+      "tags": []
+    }
+  },
+  {
+    "marker": {
+      "fileName": "/tests/cases/fourslash/jsDocTypeTag2.js",
+      "position": 200
+    },
+    "quickInfo": {
+      "kind": "var",
+      "kindModifiers": "",
+      "textSpan": {
+        "start": 200,
+        "length": 1
+      },
+      "displayParts": [
+        {
+          "text": "var",
+          "kind": "keyword"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "a",
+          "kind": "localName"
+        },
+        {
+          "text": ":",
+          "kind": "punctuation"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "any",
+          "kind": "keyword"
+        },
+        {
+          "text": "[",
+          "kind": "punctuation"
+        },
+        {
+          "text": "]",
+          "kind": "punctuation"
+        }
+      ],
+      "documentation": [],
+      "tags": []
+    }
+  },
+  {
+    "marker": {
+      "fileName": "/tests/cases/fourslash/jsDocTypeTag2.js",
+      "position": 230
+    },
+    "quickInfo": {
+      "kind": "var",
+      "kindModifiers": "",
+      "textSpan": {
+        "start": 230,
+        "length": 1
+      },
+      "displayParts": [
+        {
+          "text": "var",
+          "kind": "keyword"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "p",
+          "kind": "localName"
+        },
+        {
+          "text": ":",
+          "kind": "punctuation"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "Promise",
+          "kind": "interfaceName"
+        },
+        {
+          "text": "<",
+          "kind": "punctuation"
+        },
+        {
+          "text": "any",
+          "kind": "keyword"
+        },
+        {
+          "text": ">",
+          "kind": "punctuation"
+        }
+      ],
+      "documentation": [],
+      "tags": []
+    }
+  },
+  {
+    "marker": {
+      "fileName": "/tests/cases/fourslash/jsDocTypeTag2.js",
+      "position": 260
+    },
+    "quickInfo": {
+      "kind": "var",
+      "kindModifiers": "",
+      "textSpan": {
+        "start": 260,
+        "length": 8
+      },
+      "displayParts": [
+        {
+          "text": "var",
+          "kind": "keyword"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "nullable",
+          "kind": "localName"
+        },
+        {
+          "text": ":",
+          "kind": "punctuation"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "number",
+          "kind": "keyword"
+        }
+      ],
+      "documentation": [],
+      "tags": []
+    }
+  },
+  {
+    "marker": {
+      "fileName": "/tests/cases/fourslash/jsDocTypeTag2.js",
+      "position": 298
+    },
+    "quickInfo": {
+      "kind": "var",
+      "kindModifiers": "",
+      "textSpan": {
+        "start": 298,
+        "length": 4
+      },
+      "displayParts": [
+        {
+          "text": "var",
+          "kind": "keyword"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "func",
+          "kind": "localName"
+        },
+        {
+          "text": ":",
+          "kind": "punctuation"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "(",
+          "kind": "punctuation"
+        },
+        {
+          "text": ")",
+          "kind": "punctuation"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "=>",
+          "kind": "punctuation"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "any",
+          "kind": "keyword"
+        }
+      ],
+      "documentation": [],
+      "tags": []
+    }
+  },
+  {
+    "marker": {
+      "fileName": "/tests/cases/fourslash/jsDocTypeTag2.js",
+      "position": 349
+    },
+    "quickInfo": {
+      "kind": "var",
+      "kindModifiers": "",
+      "textSpan": {
+        "start": 349,
+        "length": 5
+      },
+      "displayParts": [
+        {
+          "text": "var",
+          "kind": "keyword"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "func1",
+          "kind": "localName"
+        },
+        {
+          "text": ":",
+          "kind": "punctuation"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "(",
+          "kind": "punctuation"
+        },
+        {
+          "text": "arg0",
+          "kind": "parameterName"
+        },
+        {
+          "text": ":",
+          "kind": "punctuation"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "number",
+          "kind": "keyword"
+        },
+        {
+          "text": ")",
+          "kind": "punctuation"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "=>",
+          "kind": "punctuation"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "number",
+          "kind": "keyword"
+        }
+      ],
+      "documentation": [],
+      "tags": []
+    }
+  },
+  {
+    "marker": {
+      "fileName": "/tests/cases/fourslash/jsDocTypeTag2.js",
+      "position": 391
+    },
+    "quickInfo": {
+      "kind": "var",
+      "kindModifiers": "",
+      "textSpan": {
+        "start": 391,
+        "length": 4
+      },
+      "displayParts": [
+        {
+          "text": "var",
+          "kind": "keyword"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "sOrn",
+          "kind": "localName"
+        },
+        {
+          "text": ":",
+          "kind": "punctuation"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "string",
+          "kind": "keyword"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "|",
+          "kind": "punctuation"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "number",
+          "kind": "keyword"
+        }
+      ],
+      "documentation": [],
+      "tags": []
+    }
+  }
+]
\ No newline at end of file
diff --git a/tests/baselines/reference/jsDocTypes2.js b/tests/baselines/reference/jsDocTypes2.js
new file mode 100644
index 00000000000..a3848704fad
--- /dev/null
+++ b/tests/baselines/reference/jsDocTypes2.js
@@ -0,0 +1,37 @@
+//// [0.js]
+// @ts-check
+/** @type {*} */
+var anyT = 2;
+
+/** @type {?} */
+var anyT1 = 2;
+anyT1 = "hi";
+
+/** @type {Function} */
+const x = (a) => a + 1;
+x(1);
+
+/** @type {function (number)} */
+const x1 = (a) => a + 1;
+x1(0);
+
+/** @type {function (number): number} */
+const x2 = (a) => a + 1;
+x2(0);
+
+//// [0.js]
+// @ts-check
+/** @type {*} */
+var anyT = 2;
+/** @type {?} */
+var anyT1 = 2;
+anyT1 = "hi";
+/** @type {Function} */
+var x = function (a) { return a + 1; };
+x(1);
+/** @type {function (number)} */
+var x1 = function (a) { return a + 1; };
+x1(0);
+/** @type {function (number): number} */
+var x2 = function (a) { return a + 1; };
+x2(0);
diff --git a/tests/baselines/reference/jsDocTypes2.symbols b/tests/baselines/reference/jsDocTypes2.symbols
new file mode 100644
index 00000000000..96b32b9ad91
--- /dev/null
+++ b/tests/baselines/reference/jsDocTypes2.symbols
@@ -0,0 +1,40 @@
+=== tests/cases/conformance/salsa/0.js ===
+// @ts-check
+/** @type {*} */
+var anyT = 2;
+>anyT : Symbol(anyT, Decl(0.js, 2, 3))
+
+/** @type {?} */
+var anyT1 = 2;
+>anyT1 : Symbol(anyT1, Decl(0.js, 5, 3))
+
+anyT1 = "hi";
+>anyT1 : Symbol(anyT1, Decl(0.js, 5, 3))
+
+/** @type {Function} */
+const x = (a) => a + 1;
+>x : Symbol(x, Decl(0.js, 9, 5))
+>a : Symbol(a, Decl(0.js, 9, 11))
+>a : Symbol(a, Decl(0.js, 9, 11))
+
+x(1);
+>x : Symbol(x, Decl(0.js, 9, 5))
+
+/** @type {function (number)} */
+const x1 = (a) => a + 1;
+>x1 : Symbol(x1, Decl(0.js, 13, 5))
+>a : Symbol(a, Decl(0.js, 13, 12))
+>a : Symbol(a, Decl(0.js, 13, 12))
+
+x1(0);
+>x1 : Symbol(x1, Decl(0.js, 13, 5))
+
+/** @type {function (number): number} */
+const x2 = (a) => a + 1;
+>x2 : Symbol(x2, Decl(0.js, 17, 5))
+>a : Symbol(a, Decl(0.js, 17, 12))
+>a : Symbol(a, Decl(0.js, 17, 12))
+
+x2(0);
+>x2 : Symbol(x2, Decl(0.js, 17, 5))
+
diff --git a/tests/baselines/reference/jsDocTypes2.types b/tests/baselines/reference/jsDocTypes2.types
new file mode 100644
index 00000000000..db5a5902d10
--- /dev/null
+++ b/tests/baselines/reference/jsDocTypes2.types
@@ -0,0 +1,59 @@
+=== tests/cases/conformance/salsa/0.js ===
+// @ts-check
+/** @type {*} */
+var anyT = 2;
+>anyT : any
+>2 : 2
+
+/** @type {?} */
+var anyT1 = 2;
+>anyT1 : any
+>2 : 2
+
+anyT1 = "hi";
+>anyT1 = "hi" : "hi"
+>anyT1 : any
+>"hi" : "hi"
+
+/** @type {Function} */
+const x = (a) => a + 1;
+>x : Function
+>(a) => a + 1 : (a: any) => any
+>a : any
+>a + 1 : any
+>a : any
+>1 : 1
+
+x(1);
+>x(1) : any
+>x : Function
+>1 : 1
+
+/** @type {function (number)} */
+const x1 = (a) => a + 1;
+>x1 : (arg0: number) => any
+>(a) => a + 1 : (a: any) => any
+>a : any
+>a + 1 : any
+>a : any
+>1 : 1
+
+x1(0);
+>x1(0) : any
+>x1 : (arg0: number) => any
+>0 : 0
+
+/** @type {function (number): number} */
+const x2 = (a) => a + 1;
+>x2 : (arg0: number) => number
+>(a) => a + 1 : (a: any) => any
+>a : any
+>a + 1 : any
+>a : any
+>1 : 1
+
+x2(0);
+>x2(0) : number
+>x2 : (arg0: number) => number
+>0 : 0
+
diff --git a/tests/baselines/reference/jsDocTypes3.errors.txt b/tests/baselines/reference/jsDocTypes3.errors.txt
new file mode 100644
index 00000000000..5f5feeaf0a7
--- /dev/null
+++ b/tests/baselines/reference/jsDocTypes3.errors.txt
@@ -0,0 +1,21 @@
+tests/cases/conformance/salsa/0.js(5,4): error TS2345: Argument of type '"string"' is not assignable to parameter of type 'number'.
+tests/cases/conformance/salsa/0.js(12,1): error TS2322: Type 'number' is not assignable to type 'string'.
+
+
+==== tests/cases/conformance/salsa/0.js (2 errors) ====
+    // @ts-check
+    
+    /** @type {function (number)} */
+    const x1 = (a) => a + 1;
+    x1("string");
+       ~~~~~~~~
+!!! error TS2345: Argument of type '"string"' is not assignable to parameter of type 'number'.
+    
+    /** @type {function (number): number} */
+    const x2 = (a) => a + 1;
+    
+    /** @type {string} */
+    var a;
+    a = x2(0);
+    ~
+!!! error TS2322: Type 'number' is not assignable to type 'string'.
\ No newline at end of file
diff --git a/tests/baselines/reference/jsDocTypes3.js b/tests/baselines/reference/jsDocTypes3.js
new file mode 100644
index 00000000000..2eb50223ba2
--- /dev/null
+++ b/tests/baselines/reference/jsDocTypes3.js
@@ -0,0 +1,24 @@
+//// [0.js]
+// @ts-check
+
+/** @type {function (number)} */
+const x1 = (a) => a + 1;
+x1("string");
+
+/** @type {function (number): number} */
+const x2 = (a) => a + 1;
+
+/** @type {string} */
+var a;
+a = x2(0);
+
+//// [0.js]
+// @ts-check
+/** @type {function (number)} */
+var x1 = function (a) { return a + 1; };
+x1("string");
+/** @type {function (number): number} */
+var x2 = function (a) { return a + 1; };
+/** @type {string} */
+var a;
+a = x2(0);
diff --git a/tests/cases/conformance/salsa/jsDocTypes2.ts b/tests/cases/conformance/salsa/jsDocTypes2.ts
new file mode 100644
index 00000000000..612804b91d7
--- /dev/null
+++ b/tests/cases/conformance/salsa/jsDocTypes2.ts
@@ -0,0 +1,23 @@
+// @allowJS: true
+// @suppressOutputPathCheck: true
+
+// @filename: 0.js
+// @ts-check
+/** @type {*} */
+var anyT = 2;
+
+/** @type {?} */
+var anyT1 = 2;
+anyT1 = "hi";
+
+/** @type {Function} */
+const x = (a) => a + 1;
+x(1);
+
+/** @type {function (number)} */
+const x1 = (a) => a + 1;
+x1(0);
+
+/** @type {function (number): number} */
+const x2 = (a) => a + 1;
+x2(0);
\ No newline at end of file
diff --git a/tests/cases/conformance/salsa/jsDocTypes3.ts b/tests/cases/conformance/salsa/jsDocTypes3.ts
new file mode 100644
index 00000000000..bf207bca869
--- /dev/null
+++ b/tests/cases/conformance/salsa/jsDocTypes3.ts
@@ -0,0 +1,16 @@
+// @allowJS: true
+// @suppressOutputPathCheck: true
+
+// @filename: 0.js
+// @ts-check
+
+/** @type {function (number)} */
+const x1 = (a) => a + 1;
+x1("string");
+
+/** @type {function (number): number} */
+const x2 = (a) => a + 1;
+
+/** @type {string} */
+var a;
+a = x2(0);
\ No newline at end of file
diff --git a/tests/cases/fourslash/jsDocTypeTagQuickInfo1.ts b/tests/cases/fourslash/jsDocTypeTagQuickInfo1.ts
new file mode 100644
index 00000000000..240c00e2283
--- /dev/null
+++ b/tests/cases/fourslash/jsDocTypeTagQuickInfo1.ts
@@ -0,0 +1,43 @@
+/// <reference path="fourslash.ts" />
+// @allowJs: true
+// @Filename: jsDocTypeTag1.js
+//// /** @type {String} */
+//// var /*1*/S;
+
+//// /** @type {Number} */
+//// var /*2*/N;
+
+//// /** @type {Boolean} */
+//// var /*3*/B;
+
+//// /** @type {Void} */
+//// var /*4*/V;
+
+//// /** @type {Undefined} */
+//// var /*5*/U;
+
+//// /** @type {Null} */
+//// var /*6*/Nl;
+
+//// /** @type {Array} */
+//// var /*7*/A;
+
+//// /** @type {Promise} */
+//// var /*8*/P;
+
+//// /** @type {Object} */
+//// var /*9*/Obj;
+
+//// /** @type {Function} */
+//// var /*10*/Func;
+
+//// /** @type {*} */
+//// var /*11*/AnyType;
+
+//// /** @type {?} */
+//// var /*12*/QType;
+
+//// /** @type {String|Number} */
+//// var /*13*/SOrN;
+
+verify.baselineQuickInfo();
\ No newline at end of file
diff --git a/tests/cases/fourslash/jsDocTypeTagQuickInfo2.ts b/tests/cases/fourslash/jsDocTypeTagQuickInfo2.ts
new file mode 100644
index 00000000000..7c79116b041
--- /dev/null
+++ b/tests/cases/fourslash/jsDocTypeTagQuickInfo2.ts
@@ -0,0 +1,40 @@
+/// <reference path="fourslash.ts" />
+// @allowJs: true
+// @Filename: jsDocTypeTag2.js
+//// /** @type {string} */
+//// var /*1*/s;
+
+//// /** @type {number} */
+//// var /*2*/n;
+
+//// /** @type {boolean} */
+//// var /*3*/b;
+
+//// /** @type {void} */
+//// var /*4*/v;
+
+//// /** @type {undefined} */
+//// var /*5*/u;
+
+//// /** @type {null} */
+//// var /*6*/nl;
+
+//// /** @type {array} */
+//// var /*7*/a;
+
+//// /** @type {promise} */
+//// var /*8*/p;
+
+//// /** @type {?number} */
+//// var /*9*/nullable;
+
+//// /** @type {function} */
+//// var /*10*/func;
+
+//// /** @type {function (number): number} */
+//// var /*11*/func1;
+
+//// /** @type {string | number} */
+//// var /*12*/sOrn;
+
+verify.baselineQuickInfo();
\ No newline at end of file

From b0de80f07efb9e6f1ddde1f7e2b471a47f9ec212 Mon Sep 17 00:00:00 2001
From: Andy Hanson <anhans@microsoft.com>
Date: Wed, 24 May 2017 08:14:52 -0700
Subject: [PATCH 20/56] Set '.declarations' on a property of a homomorphic
 mapped type

---
 src/compiler/checker.ts                       |  1 +
 .../server/quickInfoMappedSpreadTypes.ts      | 30 +++++++++++++++++++
 2 files changed, 31 insertions(+)
 create mode 100644 tests/cases/fourslash/server/quickInfoMappedSpreadTypes.ts

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index ce982a113f2..e3aedd5fe51 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -5690,6 +5690,7 @@ namespace ts {
                     prop.type = propType;
                     if (propertySymbol) {
                         prop.syntheticOrigin = propertySymbol;
+                        prop.declarations = propertySymbol.declarations;
                     }
                     members.set(propName, prop);
                 }
diff --git a/tests/cases/fourslash/server/quickInfoMappedSpreadTypes.ts b/tests/cases/fourslash/server/quickInfoMappedSpreadTypes.ts
new file mode 100644
index 00000000000..2a0c1668763
--- /dev/null
+++ b/tests/cases/fourslash/server/quickInfoMappedSpreadTypes.ts
@@ -0,0 +1,30 @@
+/// <reference path="../fourslash.ts"/>
+
+////interface Foo {
+////    /** Doc */
+////    bar: number;
+////}
+////
+////const f: Foo = { bar: 0 };
+////f./*f*/bar;
+////
+////const f2: { [TKey in keyof Foo]: string } = { bar: "0" };
+////f2./*f2*/bar;
+////
+////const f3 = { ...f };
+////f3./*f3*/bar;
+////
+////const f4 = { ...f2 };
+////f4./*f4*/bar;
+
+goTo.marker("f");
+verify.quickInfoIs("(property) Foo.bar: number", "Doc ");
+
+goTo.marker("f2");
+verify.quickInfoIs("(property) bar: string", "Doc ");
+
+goTo.marker("f3");
+verify.quickInfoIs("(property) Foo.bar: number", "Doc ");
+
+goTo.marker("f4");
+verify.quickInfoIs("(property) bar: string", "Doc ");

From 34bb955655554a5b8818b1f97696ef0881bdf7ea Mon Sep 17 00:00:00 2001
From: Andy Hanson <anhans@microsoft.com>
Date: Wed, 24 May 2017 08:42:02 -0700
Subject: [PATCH 21/56] Use `orderedRemoveItem` instead of `remove` helper

---
 src/server/project.ts | 9 +--------
 1 file changed, 1 insertion(+), 8 deletions(-)

diff --git a/src/server/project.ts b/src/server/project.ts
index 6372d1f5c03..7dc4388bf39 100644
--- a/src/server/project.ts
+++ b/src/server/project.ts
@@ -13,13 +13,6 @@ namespace ts.server {
         External
     }
 
-    function remove<T>(items: T[], item: T) {
-        const index = items.indexOf(item);
-        if (index >= 0) {
-            items.splice(index, 1);
-        }
-    }
-
     function countEachFileTypes(infos: ScriptInfo[]): { js: number, jsx: number, ts: number, tsx: number, dts: number } {
         const result = { js: 0, jsx: 0, ts: 0, tsx: 0, dts: 0 };
         for (const info of infos) {
@@ -732,7 +725,7 @@ namespace ts.server {
 
         // remove a root file from project
         protected removeRoot(info: ScriptInfo): void {
-            remove(this.rootFiles, info);
+            orderedRemoveItem(this.rootFiles, info);
             this.rootFilesMap.remove(info.path);
         }
     }

From f309996b329702da7ad2725dade35c4b950f4a47 Mon Sep 17 00:00:00 2001
From: Donald Pipowitch <pipo@senaeh.de>
Date: Wed, 24 May 2017 18:50:38 +0200
Subject: [PATCH 22/56] added es2017.intl (#15369)

---
 Gulpfile.ts                                            |  1 +
 Jakefile.js                                            |  3 ++-
 lib/lib.es2017.d.ts                                    |  3 ++-
 lib/lib.es2017.full.d.ts                               |  1 +
 lib/tsc.js                                             |  1 +
 lib/tsserver.js                                        |  1 +
 lib/tsserverlibrary.js                                 |  1 +
 lib/typescript.js                                      |  1 +
 lib/typescriptServices.js                              |  1 +
 lib/typingsInstaller.js                                |  1 +
 src/compiler/commandLineParser.ts                      |  3 ++-
 src/harness/unittests/commandLineParsing.ts            |  6 +++---
 .../unittests/convertCompilerOptionsFromJson.ts        |  8 ++++----
 src/lib/es2017.d.ts                                    |  3 ++-
 src/lib/es2017.intl.d.ts                               | 10 ++++++++++
 15 files changed, 33 insertions(+), 11 deletions(-)
 create mode 100644 src/lib/es2017.intl.d.ts

diff --git a/Gulpfile.ts b/Gulpfile.ts
index 03046789fe1..d856254296e 100644
--- a/Gulpfile.ts
+++ b/Gulpfile.ts
@@ -131,6 +131,7 @@ const es2017LibrarySource = [
     "es2017.object.d.ts",
     "es2017.sharedmemory.d.ts",
     "es2017.string.d.ts",
+    "es2017.intl.d.ts",
 ];
 
 const es2017LibrarySourceMap = es2017LibrarySource.map(function(source) {
diff --git a/Jakefile.js b/Jakefile.js
index 807546d59f8..577ade2ef69 100644
--- a/Jakefile.js
+++ b/Jakefile.js
@@ -172,7 +172,8 @@ var es2016LibrarySourceMap = es2016LibrarySource.map(function (source) {
 var es2017LibrarySource = [
     "es2017.object.d.ts",
     "es2017.sharedmemory.d.ts",
-    "es2017.string.d.ts"
+    "es2017.string.d.ts",
+    "es2017.intl.d.ts"
 ];
 
 var es2017LibrarySourceMap = es2017LibrarySource.map(function (source) {
diff --git a/lib/lib.es2017.d.ts b/lib/lib.es2017.d.ts
index a0d3a0aff28..64ebe606847 100644
--- a/lib/lib.es2017.d.ts
+++ b/lib/lib.es2017.d.ts
@@ -21,4 +21,5 @@ and limitations under the License.
 /// <reference path="lib.es2016.d.ts" />
 /// <reference path="lib.es2017.object.d.ts" />
 /// <reference path="lib.es2017.sharedmemory.d.ts" />
-/// <reference path="lib.es2017.string.d.ts" />
\ No newline at end of file
+/// <reference path="lib.es2017.string.d.ts" />
+/// <reference path="lib.es2017.intl.d.ts" />
\ No newline at end of file
diff --git a/lib/lib.es2017.full.d.ts b/lib/lib.es2017.full.d.ts
index d70049b1309..91bee6e9d56 100644
--- a/lib/lib.es2017.full.d.ts
+++ b/lib/lib.es2017.full.d.ts
@@ -22,6 +22,7 @@ and limitations under the License.
 /// <reference path="lib.es2017.object.d.ts" />
 /// <reference path="lib.es2017.sharedmemory.d.ts" />
 /// <reference path="lib.es2017.string.d.ts" />
+/// <reference path="lib.es2017.intl.d.ts" />
 
 declare type PropertyKey = string | number | symbol;
 
diff --git a/lib/tsc.js b/lib/tsc.js
index 1d92d339b9d..4c846c034f8 100644
--- a/lib/tsc.js
+++ b/lib/tsc.js
@@ -56880,6 +56880,7 @@ var ts;
                     "es2017.object": "lib.es2017.object.d.ts",
                     "es2017.sharedmemory": "lib.es2017.sharedmemory.d.ts",
                     "es2017.string": "lib.es2017.string.d.ts",
+                    "es2017.intl": "lib.es2017.intl.d.ts",
                     "esnext.asynciterable": "lib.esnext.asynciterable.d.ts",
                 }),
             },
diff --git a/lib/tsserver.js b/lib/tsserver.js
index ae6c3c8dc07..0e99abde9da 100644
--- a/lib/tsserver.js
+++ b/lib/tsserver.js
@@ -56898,6 +56898,7 @@ var ts;
                     "es2017.object": "lib.es2017.object.d.ts",
                     "es2017.sharedmemory": "lib.es2017.sharedmemory.d.ts",
                     "es2017.string": "lib.es2017.string.d.ts",
+                    "es2017.intl": "lib.es2017.intl.d.ts",
                     "esnext.asynciterable": "lib.esnext.asynciterable.d.ts",
                 }),
             },
diff --git a/lib/tsserverlibrary.js b/lib/tsserverlibrary.js
index e23edda9295..128438ce66a 100644
--- a/lib/tsserverlibrary.js
+++ b/lib/tsserverlibrary.js
@@ -6079,6 +6079,7 @@ var ts;
                     "es2017.object": "lib.es2017.object.d.ts",
                     "es2017.sharedmemory": "lib.es2017.sharedmemory.d.ts",
                     "es2017.string": "lib.es2017.string.d.ts",
+                    "es2017.intl": "lib.es2017.intl.d.ts",
                     "esnext.asynciterable": "lib.esnext.asynciterable.d.ts",
                 }),
             },
diff --git a/lib/typescript.js b/lib/typescript.js
index a73895f4f74..9f28644b4e5 100644
--- a/lib/typescript.js
+++ b/lib/typescript.js
@@ -69276,6 +69276,7 @@ var ts;
                     "es2017.object": "lib.es2017.object.d.ts",
                     "es2017.sharedmemory": "lib.es2017.sharedmemory.d.ts",
                     "es2017.string": "lib.es2017.string.d.ts",
+                    "es2017.intl": "lib.es2017.intl.d.ts",
                     "esnext.asynciterable": "lib.esnext.asynciterable.d.ts",
                 }),
             },
diff --git a/lib/typescriptServices.js b/lib/typescriptServices.js
index a73895f4f74..9f28644b4e5 100644
--- a/lib/typescriptServices.js
+++ b/lib/typescriptServices.js
@@ -69276,6 +69276,7 @@ var ts;
                     "es2017.object": "lib.es2017.object.d.ts",
                     "es2017.sharedmemory": "lib.es2017.sharedmemory.d.ts",
                     "es2017.string": "lib.es2017.string.d.ts",
+                    "es2017.intl": "lib.es2017.intl.d.ts",
                     "esnext.asynciterable": "lib.esnext.asynciterable.d.ts",
                 }),
             },
diff --git a/lib/typingsInstaller.js b/lib/typingsInstaller.js
index 4efda1e469e..554dc3bcaca 100644
--- a/lib/typingsInstaller.js
+++ b/lib/typingsInstaller.js
@@ -6071,6 +6071,7 @@ var ts;
                     "es2017.object": "lib.es2017.object.d.ts",
                     "es2017.sharedmemory": "lib.es2017.sharedmemory.d.ts",
                     "es2017.string": "lib.es2017.string.d.ts",
+                    "es2017.intl": "lib.es2017.intl.d.ts",
                     "esnext.asynciterable": "lib.esnext.asynciterable.d.ts",
                 }),
             },
diff --git a/src/compiler/commandLineParser.ts b/src/compiler/commandLineParser.ts
index 9494098c072..88687357115 100644
--- a/src/compiler/commandLineParser.ts
+++ b/src/compiler/commandLineParser.ts
@@ -139,6 +139,7 @@ namespace ts {
                     "es2017.object": "lib.es2017.object.d.ts",
                     "es2017.sharedmemory": "lib.es2017.sharedmemory.d.ts",
                     "es2017.string": "lib.es2017.string.d.ts",
+                    "es2017.intl": "lib.es2017.intl.d.ts",
                     "esnext.asynciterable": "lib.esnext.asynciterable.d.ts",
                 }),
             },
@@ -1704,4 +1705,4 @@ namespace ts {
     function caseInsensitiveKeyMapper(key: string) {
         return key.toLowerCase();
     }
-}
\ No newline at end of file
+}
diff --git a/src/harness/unittests/commandLineParsing.ts b/src/harness/unittests/commandLineParsing.ts
index 61b96d89553..19ccc919d4c 100644
--- a/src/harness/unittests/commandLineParsing.ts
+++ b/src/harness/unittests/commandLineParsing.ts
@@ -60,7 +60,7 @@ namespace ts {
             assertParseResult(["--lib", "es5,invalidOption", "0.ts"],
                 {
                     errors: [{
-                        messageText: "Argument for '--lib' option must be: 'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'esnext', 'dom', 'dom.iterable', 'webworker', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory', 'es2017.string', 'esnext.asynciterable'.",
+                        messageText: "Argument for '--lib' option must be: 'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'esnext', 'dom', 'dom.iterable', 'webworker', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory', 'es2017.string', 'es2017.intl', 'esnext.asynciterable'.",
                         category: ts.Diagnostics.Argument_for_0_option_must_be_Colon_1.category,
                         code: ts.Diagnostics.Argument_for_0_option_must_be_Colon_1.code,
 
@@ -263,7 +263,7 @@ namespace ts {
             assertParseResult(["--lib", "es5,", "es7", "0.ts"],
                 {
                     errors: [{
-                        messageText: "Argument for '--lib' option must be: 'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'esnext', 'dom', 'dom.iterable', 'webworker', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory', 'es2017.string', 'esnext.asynciterable'.",
+                        messageText: "Argument for '--lib' option must be: 'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'esnext', 'dom', 'dom.iterable', 'webworker', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory', 'es2017.string', 'es2017.intl', 'esnext.asynciterable'.",
                         category: ts.Diagnostics.Argument_for_0_option_must_be_Colon_1.category,
                         code: ts.Diagnostics.Argument_for_0_option_must_be_Colon_1.code,
 
@@ -283,7 +283,7 @@ namespace ts {
             assertParseResult(["--lib", "es5, ", "es7", "0.ts"],
                 {
                     errors: [{
-                        messageText: "Argument for '--lib' option must be: 'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'esnext', 'dom', 'dom.iterable', 'webworker', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory', 'es2017.string', 'esnext.asynciterable'.",
+                        messageText: "Argument for '--lib' option must be: 'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'esnext', 'dom', 'dom.iterable', 'webworker', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory', 'es2017.string', 'es2017.intl', 'esnext.asynciterable'.",
                         category: ts.Diagnostics.Argument_for_0_option_must_be_Colon_1.category,
                         code: ts.Diagnostics.Argument_for_0_option_must_be_Colon_1.code,
 
diff --git a/src/harness/unittests/convertCompilerOptionsFromJson.ts b/src/harness/unittests/convertCompilerOptionsFromJson.ts
index 0409ee19e66..3aa1a4c9b8e 100644
--- a/src/harness/unittests/convertCompilerOptionsFromJson.ts
+++ b/src/harness/unittests/convertCompilerOptionsFromJson.ts
@@ -233,7 +233,7 @@ namespace ts {
                         file: undefined,
                         start: 0,
                         length: 0,
-                        messageText: "Argument for '--lib' option must be: 'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'esnext', 'dom', 'dom.iterable', 'webworker', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory', 'es2017.string', 'esnext.asynciterable'.",
+                        messageText: "Argument for '--lib' option must be: 'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'esnext', 'dom', 'dom.iterable', 'webworker', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory', 'es2017.string', 'es2017.intl', 'esnext.asynciterable'.",
                         code: Diagnostics.Argument_for_0_option_must_be_Colon_1.code,
                         category: Diagnostics.Argument_for_0_option_must_be_Colon_1.category
                     }]
@@ -264,7 +264,7 @@ namespace ts {
                         file: undefined,
                         start: 0,
                         length: 0,
-                        messageText: "Argument for '--lib' option must be: 'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'esnext', 'dom', 'dom.iterable', 'webworker', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory', 'es2017.string', 'esnext.asynciterable'.",
+                        messageText: "Argument for '--lib' option must be: 'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'esnext', 'dom', 'dom.iterable', 'webworker', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory', 'es2017.string', 'es2017.intl', 'esnext.asynciterable'.",
                         code: Diagnostics.Argument_for_0_option_must_be_Colon_1.code,
                         category: Diagnostics.Argument_for_0_option_must_be_Colon_1.category
                     }]
@@ -295,7 +295,7 @@ namespace ts {
                         file: undefined,
                         start: 0,
                         length: 0,
-                        messageText: "Argument for '--lib' option must be: 'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'esnext', 'dom', 'dom.iterable', 'webworker', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory', 'es2017.string', 'esnext.asynciterable'.",
+                        messageText: "Argument for '--lib' option must be: 'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'esnext', 'dom', 'dom.iterable', 'webworker', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory', 'es2017.string', 'es2017.intl', 'esnext.asynciterable'.",
                         code: Diagnostics.Argument_for_0_option_must_be_Colon_1.code,
                         category: Diagnostics.Argument_for_0_option_must_be_Colon_1.category
                     }]
@@ -326,7 +326,7 @@ namespace ts {
                         file: undefined,
                         start: 0,
                         length: 0,
-                        messageText: "Argument for '--lib' option must be: 'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'esnext', 'dom', 'dom.iterable', 'webworker', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory', 'es2017.string', 'esnext.asynciterable'.",
+                        messageText: "Argument for '--lib' option must be: 'es5', 'es6', 'es2015', 'es7', 'es2016', 'es2017', 'esnext', 'dom', 'dom.iterable', 'webworker', 'scripthost', 'es2015.core', 'es2015.collection', 'es2015.generator', 'es2015.iterable', 'es2015.promise', 'es2015.proxy', 'es2015.reflect', 'es2015.symbol', 'es2015.symbol.wellknown', 'es2016.array.include', 'es2017.object', 'es2017.sharedmemory', 'es2017.string', 'es2017.intl', 'esnext.asynciterable'.",
                         code: Diagnostics.Argument_for_0_option_must_be_Colon_1.code,
                         category: Diagnostics.Argument_for_0_option_must_be_Colon_1.category
                     }]
diff --git a/src/lib/es2017.d.ts b/src/lib/es2017.d.ts
index 7b8c7cbb7d5..80282355a45 100644
--- a/src/lib/es2017.d.ts
+++ b/src/lib/es2017.d.ts
@@ -1,4 +1,5 @@
 /// <reference path="lib.es2016.d.ts" />
 /// <reference path="lib.es2017.object.d.ts" />
 /// <reference path="lib.es2017.sharedmemory.d.ts" />
-/// <reference path="lib.es2017.string.d.ts" />
\ No newline at end of file
+/// <reference path="lib.es2017.string.d.ts" />
+/// <reference path="lib.es2017.intl.d.ts" />
diff --git a/src/lib/es2017.intl.d.ts b/src/lib/es2017.intl.d.ts
new file mode 100644
index 00000000000..b8783530190
--- /dev/null
+++ b/src/lib/es2017.intl.d.ts
@@ -0,0 +1,10 @@
+type DateTimeFormatPartTypes = "day" | "dayPeriod" | "era" | "hour" | "literal" | "minute" | "month" | "second" | "timeZoneName" | "weekday" | "year";
+
+interface DateTimeFormatPart {
+    type: DateTimeFormatPartTypes;
+    value: string;
+}
+
+interface DateTimeFormat {
+    formatToParts(date?: Date | number): DateTimeFormatPart[];
+}

From 77e2f097c36ee66239a1715ac3154c79f457f5e4 Mon Sep 17 00:00:00 2001
From: Anders Hejlsberg <andersh@microsoft.com>
Date: Wed, 24 May 2017 10:44:19 -0700
Subject: [PATCH 23/56] InferenceContext is-a TypeMapper instead of has-a
 TypeMapper

---
 src/compiler/checker.ts | 71 +++++++++++++++++------------------------
 src/compiler/types.ts   |  8 ++---
 2 files changed, 32 insertions(+), 47 deletions(-)

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index de0feae2f08..e323d97d781 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -7918,27 +7918,14 @@ namespace ts {
             return mapper;
         }
 
-        function getInferenceMapper(context: InferenceContext): TypeMapper {
-            if (!context.mapper) {
-                const mapper: TypeMapper = t => {
-                    const inferences = context.inferences;
-                    for (let i = 0; i < inferences.length; i++) {
-                        if (t === inferences[i].typeParameter) {
-                            inferences[i].isFixed = true;
-                            return getInferredType(context, i);
-                        }
-                    }
-                    return t;
-                };
-                mapper.mappedTypes = context.signature.typeParameters;
-                mapper.context = context;
-                context.mapper = mapper;
-            }
-            return context.mapper;
+        function isInferenceContext(mapper: TypeMapper): mapper is InferenceContext {
+            return !!(<InferenceContext>mapper).signature;
         }
 
         function cloneTypeMapper(mapper: TypeMapper): TypeMapper {
-            return mapper && mapper.context ? getInferenceMapper(cloneInferenceContext(mapper.context)) : mapper;
+            return mapper && isInferenceContext(mapper) ?
+                createInferenceContext(mapper.callNode, mapper.signature, mapper.flags | InferenceFlags.NoDefault, mapper.inferences) :
+                mapper;
         }
 
         function identityMapper(type: Type): Type {
@@ -10134,13 +10121,25 @@ namespace ts {
             }
         }
 
-        function createInferenceContext(callNode: CallLikeExpression, signature: Signature, flags: InferenceFlags): InferenceContext {
-            return {
-                callNode,
-                signature,
-                inferences: map(signature.typeParameters, createInferenceInfo),
-                flags,
-            };
+        function createInferenceContext(callNode: CallLikeExpression, signature: Signature, flags: InferenceFlags, baseInferences?: InferenceInfo[]): InferenceContext {
+            const inferences = baseInferences ? map(baseInferences, cloneInferenceInfo) : map(signature.typeParameters, createInferenceInfo);
+            const context = mapper as InferenceContext;
+            context.mappedTypes = signature.typeParameters;
+            context.callNode = callNode;
+            context.signature = signature;
+            context.inferences = inferences;
+            context.flags = flags;
+            return context;
+
+            function mapper(t: Type): Type {
+                for (let i = 0; i < inferences.length; i++) {
+                    if (t === inferences[i].typeParameter) {
+                        inferences[i].isFixed = true;
+                        return getInferredType(context, i);
+                    }
+                }
+                return t;
+            }
         }
 
         function createInferenceInfo(typeParameter: TypeParameter): InferenceInfo {
@@ -10154,15 +10153,6 @@ namespace ts {
             };
         }
 
-        function cloneInferenceContext(context: InferenceContext): InferenceContext {
-            return {
-                callNode: context.callNode,
-                signature: context.signature,
-                inferences: map(context.inferences, cloneInferenceInfo),
-                flags: context.flags | InferenceFlags.NoDefault
-            };
-        }
-
         function cloneInferenceInfo(inference: InferenceInfo): InferenceInfo {
             return {
                 typeParameter: inference.typeParameter,
@@ -10586,7 +10576,7 @@ namespace ts {
                             inferredType = instantiateType(defaultType,
                                 combineTypeMappers(
                                     createBackreferenceMapper(context.signature.typeParameters, index),
-                                    getInferenceMapper(context)));
+                                    context));
                         }
                         else {
                             inferredType = context.flags & InferenceFlags.AnyDefault ? anyType : emptyObjectType;
@@ -10600,7 +10590,7 @@ namespace ts {
                 if (inferenceSucceeded) {
                     const constraint = getConstraintOfTypeParameter(context.signature.typeParameters[index]);
                     if (constraint) {
-                        const instantiatedConstraint = instantiateType(constraint, getInferenceMapper(context));
+                        const instantiatedConstraint = instantiateType(constraint, context);
                         if (!isTypeAssignableTo(inferredType, getTypeWithThisArgument(instantiatedConstraint, inferredType))) {
                             inference.inferredType = inferredType = instantiatedConstraint;
                         }
@@ -14886,7 +14876,6 @@ namespace ts {
 
         function inferTypeArguments(node: CallLikeExpression, signature: Signature, args: Expression[], excludeArgument: boolean[], context: InferenceContext): Type[] {
             const inferences = context.inferences;
-            const inferenceMapper = getInferenceMapper(context);
 
             // Clear out all the inference results from the last time inferTypeArguments was called on this context
             for (let i = 0; i < inferences.length; i++) {
@@ -14932,7 +14921,7 @@ namespace ts {
                     if (argType === undefined) {
                         // For context sensitive arguments we pass the identityMapper, which is a signal to treat all
                         // context sensitive function expressions as wildcards
-                        const mapper = excludeArgument && excludeArgument[i] !== undefined ? identityMapper : inferenceMapper;
+                        const mapper = excludeArgument && excludeArgument[i] !== undefined ? identityMapper : context;
                         argType = checkExpressionWithContextualType(arg, paramType, mapper);
                     }
 
@@ -14951,7 +14940,7 @@ namespace ts {
                     if (excludeArgument[i] === false) {
                         const arg = args[i];
                         const paramType = getTypeAtPosition(signature, i);
-                        inferTypes(context.inferences, checkExpressionWithContextualType(arg, paramType, inferenceMapper), paramType);
+                        inferTypes(context.inferences, checkExpressionWithContextualType(arg, paramType, context), paramType);
                     }
                 }
             }
@@ -16196,7 +16185,7 @@ namespace ts {
                 for (let i = 0; i < len; i++) {
                     const declaration = <ParameterDeclaration>signature.parameters[i].valueDeclaration;
                     if (declaration.type) {
-                        inferTypes(mapper.context.inferences, getTypeFromTypeNode(declaration.type), getTypeAtPosition(context, i));
+                        inferTypes((<InferenceContext>mapper).inferences, getTypeFromTypeNode(declaration.type), getTypeAtPosition(context, i));
                     }
                 }
             }
@@ -16282,7 +16271,7 @@ namespace ts {
                 // T in the second overload so that we do not infer Base as a candidate for T
                 // (inferring Base would make type argument inference inconsistent between the two
                 // overloads).
-                inferTypes(mapper.context.inferences, links.type, instantiateType(contextualType, mapper));
+                inferTypes((<InferenceContext>mapper).inferences, links.type, instantiateType(contextualType, mapper));
             }
         }
 
diff --git a/src/compiler/types.ts b/src/compiler/types.ts
index 08cccd35d7a..9a36f0b285f 100644
--- a/src/compiler/types.ts
+++ b/src/compiler/types.ts
@@ -3336,9 +3336,6 @@ namespace ts {
         (t: TypeParameter): Type;
         mappedTypes?: Type[];       // Types mapped by this mapper
         instantiations?: Type[];    // Cache of instantiations created using this type mapper.
-        context?: InferenceContext; // The inference context this mapper was created from.
-                                    // Only inference mappers have this set (in createInferenceMapper).
-                                    // The identity mapper and regular instantiation mappers do not need it.
     }
 
     export const enum InferencePriority {
@@ -3363,12 +3360,11 @@ namespace ts {
     }
 
     /* @internal */
-    export interface InferenceContext {
+    export interface InferenceContext extends TypeMapper {
         callNode: CallLikeExpression;       // Call expression node for which inferences are made
         signature: Signature;               // Generic signature for which inferences are made
         inferences: InferenceInfo[];        // Inferences made for each type parameter
-        flags: InferenceFlags;              // Infer union types for disjoint candidates (otherwise undefinedType)
-        mapper?: TypeMapper;                // Type mapper for this inference context
+        flags: InferenceFlags;              // Inference flags
         failedTypeParameterIndex?: number;  // Index of type parameter for which inference failed
         // It is optional because in contextual signature instantiation, nothing fails
     }

From a2ba649ddd9416c53d951b6512dba157418097df Mon Sep 17 00:00:00 2001
From: Kanchalai Tanglertsampan <yuisu@microsoft.com>
Date: Wed, 24 May 2017 10:54:08 -0700
Subject: [PATCH 24/56] Fix emit duplicate comment

---
 src/compiler/emitter.ts                                  | 2 +-
 tests/baselines/reference/alwaysStrictModule3.js         | 1 -
 tests/baselines/reference/alwaysStrictModule5.js         | 1 -
 tests/baselines/reference/capturedLetConstInLoop4_ES6.js | 1 -
 4 files changed, 1 insertion(+), 4 deletions(-)

diff --git a/src/compiler/emitter.ts b/src/compiler/emitter.ts
index aef1a61e080..1d2f75fcd60 100644
--- a/src/compiler/emitter.ts
+++ b/src/compiler/emitter.ts
@@ -3011,7 +3011,7 @@ namespace ts {
         NoInterveningComments = 1 << 17, // Do not emit comments between each node
 
         // Precomputed Formats
-        Modifiers = SingleLine | SpaceBetweenSiblings,
+        Modifiers = SingleLine | SpaceBetweenSiblings | NoInterveningComments,
         HeritageClauses = SingleLine | SpaceBetweenSiblings,
         SingleLineTypeLiteralMembers = SingleLine | SpaceBetweenBraces | SpaceBetweenSiblings | Indented,
         MultiLineTypeLiteralMembers = MultiLine | Indented,
diff --git a/tests/baselines/reference/alwaysStrictModule3.js b/tests/baselines/reference/alwaysStrictModule3.js
index 2eb8de84028..9ba8db7052c 100644
--- a/tests/baselines/reference/alwaysStrictModule3.js
+++ b/tests/baselines/reference/alwaysStrictModule3.js
@@ -4,5 +4,4 @@ export const a = 1;
 
 //// [alwaysStrictModule3.js]
 // module ES2015
-// module ES2015
 export var a = 1;
diff --git a/tests/baselines/reference/alwaysStrictModule5.js b/tests/baselines/reference/alwaysStrictModule5.js
index 2356df0e393..664bc634627 100644
--- a/tests/baselines/reference/alwaysStrictModule5.js
+++ b/tests/baselines/reference/alwaysStrictModule5.js
@@ -4,5 +4,4 @@ export const a = 1;
 
 //// [alwaysStrictModule5.js]
 // Targeting ES6
-// Targeting ES6
 export const a = 1;
diff --git a/tests/baselines/reference/capturedLetConstInLoop4_ES6.js b/tests/baselines/reference/capturedLetConstInLoop4_ES6.js
index b1b60535475..e7a16aa01c6 100644
--- a/tests/baselines/reference/capturedLetConstInLoop4_ES6.js
+++ b/tests/baselines/reference/capturedLetConstInLoop4_ES6.js
@@ -144,7 +144,6 @@ for (const y = 0; y < 1;) {
 
 //// [capturedLetConstInLoop4_ES6.js]
 //======let
-//======let
 export function exportedFoo() {
     return v0 + v00 + v1 + v2 + v3 + v4 + v5 + v6 + v7 + v8;
 }

From b8d5eff8ace9ee4c6dc46a0c80be126c51983756 Mon Sep 17 00:00:00 2001
From: Anders Hejlsberg <andersh@microsoft.com>
Date: Wed, 24 May 2017 15:31:10 -0700
Subject: [PATCH 25/56] Move return type inference to inferTypeArguments
 function

---
 src/compiler/checker.ts | 49 ++++++++++++++++++++---------------------
 src/compiler/types.ts   |  1 -
 2 files changed, 24 insertions(+), 26 deletions(-)

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index e323d97d781..30100332210 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -7924,7 +7924,7 @@ namespace ts {
 
         function cloneTypeMapper(mapper: TypeMapper): TypeMapper {
             return mapper && isInferenceContext(mapper) ?
-                createInferenceContext(mapper.callNode, mapper.signature, mapper.flags | InferenceFlags.NoDefault, mapper.inferences) :
+                createInferenceContext(mapper.signature, mapper.flags | InferenceFlags.NoDefault, mapper.inferences) :
                 mapper;
         }
 
@@ -10121,11 +10121,10 @@ namespace ts {
             }
         }
 
-        function createInferenceContext(callNode: CallLikeExpression, signature: Signature, flags: InferenceFlags, baseInferences?: InferenceInfo[]): InferenceContext {
+        function createInferenceContext(signature: Signature, flags: InferenceFlags, baseInferences?: InferenceInfo[]): InferenceContext {
             const inferences = baseInferences ? map(baseInferences, cloneInferenceInfo) : map(signature.typeParameters, createInferenceInfo);
             const context = mapper as InferenceContext;
             context.mappedTypes = signature.typeParameters;
-            context.callNode = callNode;
             context.signature = signature;
             context.inferences = inferences;
             context.flags = flags;
@@ -10302,7 +10301,7 @@ namespace ts {
                             // Even if an inference is marked as fixed, we can add candidates from inferences made
                             // from the return type of generic functions (which only happens when no other candidates
                             // are present).
-                            if (!inference.isFixed || priority & InferencePriority.ReturnType) {
+                            if (!inference.isFixed) {
                                 if (!inference.candidates || priority < inference.priority) {
                                     inference.candidates = [source];
                                     inference.priority = priority;
@@ -10310,7 +10309,7 @@ namespace ts {
                                 else if (priority === inference.priority) {
                                     inference.candidates.push(source);
                                 }
-                                if (target.flags & TypeFlags.TypeParameter && !isTypeParameterAtTopLevel(originalTarget, <TypeParameter>target)) {
+                                if (!(priority & InferencePriority.ReturnType) && target.flags & TypeFlags.TypeParameter && !isTypeParameterAtTopLevel(originalTarget, <TypeParameter>target)) {
                                     inference.topLevel = false;
                                 }
                             }
@@ -10523,24 +10522,6 @@ namespace ts {
             let inferredType = inference.inferredType;
             let inferenceSucceeded: boolean;
             if (!inferredType) {
-                if (!inference.candidates && context.callNode && isExpression(context.callNode)) {
-                    // We have no inference candidates. Now attempt to get the contextual type for the call
-                    // expression associated with the context, and if a contextual type is available, infer
-                    // from that type to the return type of the call expression. For example, given a
-                    // 'function wrap<T, U>(cb: (x: T) => U): (x: T) => U' and a call expression
-                    // 'let f: (x: string) => number = wrap(s => s.length)', we infer from the declared type
-                    // of 'f' to the return type of 'wrap'.
-                    const contextualType = getContextualType(context.callNode);
-                    if (contextualType) {
-                        // We clone the contextual mapper to avoid disturbing a resolution in progress for an
-                        // outer call expression. Effectively we just want a snapshot of whatever has been
-                        // inferred for any outer call expression so far.
-                        const mapper = cloneTypeMapper(getContextualMapper(context.callNode));
-                        const instantiatedType = instantiateType(contextualType, mapper);
-                        const returnType = getReturnTypeOfSignature(context.signature);
-                        inferTypes([inference], instantiatedType, returnType, InferencePriority.ReturnType);
-                    }
-                }
                 if (inference.candidates) {
                     // We widen inferred literal types if
                     // all inferences were made to top-level ocurrences of the type parameter, and
@@ -14866,7 +14847,7 @@ namespace ts {
 
         // Instantiate a generic signature in the context of a non-generic signature (section 3.8.5 in TypeScript spec)
         function instantiateSignatureInContextOf(signature: Signature, contextualSignature: Signature, contextualMapper: TypeMapper): Signature {
-            const context = createInferenceContext(/*callNode*/ undefined, signature, InferenceFlags.InferUnionTypes);
+            const context = createInferenceContext(signature, InferenceFlags.InferUnionTypes);
             forEachMatchingParameterType(contextualSignature, signature, (source, target) => {
                 // Type parameters from outer context referenced by source type are fixed by instantiation of the source type
                 inferTypes(context.inferences, instantiateType(source, contextualMapper), target);
@@ -14899,6 +14880,24 @@ namespace ts {
                 context.failedTypeParameterIndex = undefined;
             }
 
+            // If a contextual type is available, infer from that type to the return type of the call expression. For
+            // example, given a 'function wrap<T, U>(cb: (x: T) => U): (x: T) => U' and a call expression
+            // 'let f: (x: string) => number = wrap(s => s.length)', we infer from the declared type of 'f' to the
+            // return type of 'wrap'.
+            if (isExpression(node)) {
+                const contextualType = getContextualType(node);
+                if (contextualType) {
+                    // We clone the contextual mapper to avoid disturbing a resolution in progress for an
+                    // outer call expression. Effectively we just want a snapshot of whatever has been
+                    // inferred for any outer call expression so far.
+                    const mapper = cloneTypeMapper(getContextualMapper(node));
+                    const instantiatedType = instantiateType(contextualType, mapper);
+                    const returnType = getReturnTypeOfSignature(signature);
+                    // Inferences made from return types have lower priority than all other inferences.
+                    inferTypes(context.inferences, instantiatedType, returnType, InferencePriority.ReturnType);
+                }
+            }
+
             const thisType = getThisTypeOfSignature(signature);
             if (thisType) {
                 const thisArgumentNode = getThisArgumentOfCall(node);
@@ -15599,7 +15598,7 @@ namespace ts {
                     let candidate: Signature;
                     let typeArgumentsAreValid: boolean;
                     const inferenceContext = originalCandidate.typeParameters
-                        ? createInferenceContext(node, originalCandidate, /*flags*/ isInJavaScriptFile(node) ? InferenceFlags.AnyDefault : 0)
+                        ? createInferenceContext(originalCandidate, /*flags*/ isInJavaScriptFile(node) ? InferenceFlags.AnyDefault : 0)
                         : undefined;
 
                     while (true) {
diff --git a/src/compiler/types.ts b/src/compiler/types.ts
index 9a36f0b285f..d42f975f682 100644
--- a/src/compiler/types.ts
+++ b/src/compiler/types.ts
@@ -3361,7 +3361,6 @@ namespace ts {
 
     /* @internal */
     export interface InferenceContext extends TypeMapper {
-        callNode: CallLikeExpression;       // Call expression node for which inferences are made
         signature: Signature;               // Generic signature for which inferences are made
         inferences: InferenceInfo[];        // Inferences made for each type parameter
         flags: InferenceFlags;              // Inference flags

From f29d7df5d150070eb0e3e4cf49d76560d72ea63b Mon Sep 17 00:00:00 2001
From: Anders Hejlsberg <andersh@microsoft.com>
Date: Wed, 24 May 2017 15:50:30 -0700
Subject: [PATCH 26/56] Add tests

---
 .../inferFromGenericFunctionReturnTypes1.ts   | 70 ++++++++++++++
 .../inferFromGenericFunctionReturnTypes2.ts   | 94 +++++++++++++++++++
 2 files changed, 164 insertions(+)
 create mode 100644 tests/cases/compiler/inferFromGenericFunctionReturnTypes1.ts
 create mode 100644 tests/cases/compiler/inferFromGenericFunctionReturnTypes2.ts

diff --git a/tests/cases/compiler/inferFromGenericFunctionReturnTypes1.ts b/tests/cases/compiler/inferFromGenericFunctionReturnTypes1.ts
new file mode 100644
index 00000000000..3fb454ec7e5
--- /dev/null
+++ b/tests/cases/compiler/inferFromGenericFunctionReturnTypes1.ts
@@ -0,0 +1,70 @@
+// Repro from #15680
+
+// This is a contrived class. We could do the same thing with Observables, etc.
+class SetOf<A> {
+  _store: A[];
+
+  add(a: A) {
+    this._store.push(a);
+  }
+
+  transform<B>(transformer: (a: SetOf<A>) => SetOf<B>): SetOf<B> {
+    return transformer(this);
+  }
+
+  forEach(fn: (a: A, index: number) => void) {
+      this._store.forEach((a, i) => fn(a, i));
+  }
+}
+
+function compose<A, B, C, D, E>(
+  fnA: (a: SetOf<A>) => SetOf<B>, 
+  fnB: (b: SetOf<B>) => SetOf<C>, 
+  fnC: (c: SetOf<C>) => SetOf<D>,
+  fnD: (c: SetOf<D>) => SetOf<E>,
+):(x: SetOf<A>) => SetOf<E>;
+/* ... etc ... */
+function compose<T>(...fns: ((x: T) => T)[]): (x: T) => T {
+  return (x: T) => fns.reduce((prev, fn) => fn(prev), x);
+}
+
+function map<A, B>(fn: (a: A) => B): (s: SetOf<A>) => SetOf<B> {
+  return (a: SetOf<A>) => {
+    const b: SetOf<B> = new SetOf();
+    a.forEach(x => b.add(fn(x)));
+    return b;
+  }
+}
+
+function filter<A>(predicate: (a: A) => boolean): (s: SetOf<A>) => SetOf<A> {
+  return (a: SetOf<A>) => {
+    const result = new SetOf<A>();
+    a.forEach(x => {
+      if (predicate(x)) result.add(x);
+    });
+   return result;
+  }
+}
+
+const testSet = new SetOf<number>();
+testSet.add(1);
+testSet.add(2);
+testSet.add(3);
+
+testSet.transform(
+  compose(
+    filter(x => x % 1 === 0),
+    map(x => x + x),
+    map(x => x + '!!!'),
+    map(x => x.toUpperCase())
+  )
+)
+
+testSet.transform(
+  compose(
+    filter(x => x % 1 === 0),
+    map(x => x + x),
+    map(x => 123),  // Whoops a bug
+    map(x => x.toUpperCase()) // causes an error!
+  )
+)
diff --git a/tests/cases/compiler/inferFromGenericFunctionReturnTypes2.ts b/tests/cases/compiler/inferFromGenericFunctionReturnTypes2.ts
new file mode 100644
index 00000000000..314159d363c
--- /dev/null
+++ b/tests/cases/compiler/inferFromGenericFunctionReturnTypes2.ts
@@ -0,0 +1,94 @@
+type Mapper<T, U> = (x: T) => U;
+
+declare function wrap<T, U>(cb: Mapper<T, U>): Mapper<T, U>;
+
+declare function arrayize<T, U>(cb: Mapper<T, U>): Mapper<T, U[]>;
+
+declare function combine<A, B, C>(f: (x: A) => B, g: (x: B) => C): (x: A) => C;
+
+declare function foo(f: Mapper<string, number>): void;
+
+let f1: Mapper<string, number> = s => s.length;
+let f2: Mapper<string, number> = wrap(s => s.length);
+let f3: Mapper<string, number[]> = arrayize(wrap(s => s.length));
+let f4: Mapper<string, boolean> = combine(wrap(s => s.length), wrap(n => n >= 10));
+
+foo(wrap(s => s.length));
+
+let a1 = ["a", "b"].map(s => s.length);
+let a2 = ["a", "b"].map(wrap(s => s.length));
+let a3 = ["a", "b"].map(wrap(arrayize(s => s.length)));
+let a4 = ["a", "b"].map(combine(wrap(s => s.length), wrap(n => n > 10)));
+let a5 = ["a", "b"].map(combine(identity, wrap(s => s.length)));
+let a6 = ["a", "b"].map(combine(wrap(s => s.length), identity));
+
+// This is a contrived class. We could do the same thing with Observables, etc.
+class SetOf<A> {
+  _store: A[];
+
+  add(a: A) {
+    this._store.push(a);
+  }
+
+  transform<B>(transformer: (a: SetOf<A>) => SetOf<B>): SetOf<B> {
+    return transformer(this);
+  }
+
+  forEach(fn: (a: A, index: number) => void) {
+      this._store.forEach((a, i) => fn(a, i));
+  }
+}
+
+function compose<A, B, C, D, E>(
+  fnA: (a: SetOf<A>) => SetOf<B>, 
+  fnB: (b: SetOf<B>) => SetOf<C>, 
+  fnC: (c: SetOf<C>) => SetOf<D>,
+  fnD: (c: SetOf<D>) => SetOf<E>,
+):(x: SetOf<A>) => SetOf<E>;
+/* ... etc ... */
+function compose<T>(...fns: ((x: T) => T)[]): (x: T) => T {
+  return (x: T) => fns.reduce((prev, fn) => fn(prev), x);
+}
+
+function map<A, B>(fn: (a: A) => B): (s: SetOf<A>) => SetOf<B> {
+  return (a: SetOf<A>) => {
+    const b: SetOf<B> = new SetOf();
+    a.forEach(x => b.add(fn(x)));
+    return b;
+  }
+}
+
+function filter<A>(predicate: (a: A) => boolean): (s: SetOf<A>) => SetOf<A> {
+  return (a: SetOf<A>) => {
+    const result = new SetOf<A>();
+    a.forEach(x => {
+      if (predicate(x)) result.add(x);
+    });
+   return result;
+  }
+}
+
+const testSet = new SetOf<number>();
+testSet.add(1);
+testSet.add(2);
+testSet.add(3);
+
+const t1 = testSet.transform(
+  compose(
+    filter(x => x % 1 === 0),
+    map(x => x + x),
+    map(x => x + '!!!'),
+    map(x => x.toUpperCase())
+  )
+)
+
+declare function identity<T>(x: T): T;
+
+const t2 = testSet.transform(
+  compose(
+    filter(x => x % 1 === 0),
+    identity,
+    map(x => x + '!!!'),
+    map(x => x.toUpperCase())
+  )
+)

From 5fa0fb46d181f8ad0895884f6d2a0698c868ef21 Mon Sep 17 00:00:00 2001
From: Anders Hejlsberg <andersh@microsoft.com>
Date: Wed, 24 May 2017 15:50:39 -0700
Subject: [PATCH 27/56] Accept new baselines

---
 ...FromGenericFunctionReturnTypes1.errors.txt |  77 +++
 .../inferFromGenericFunctionReturnTypes1.js   | 123 ++++
 .../inferFromGenericFunctionReturnTypes2.js   | 155 +++++
 ...ferFromGenericFunctionReturnTypes2.symbols | 480 ++++++++++++++
 ...inferFromGenericFunctionReturnTypes2.types | 600 ++++++++++++++++++
 5 files changed, 1435 insertions(+)
 create mode 100644 tests/baselines/reference/inferFromGenericFunctionReturnTypes1.errors.txt
 create mode 100644 tests/baselines/reference/inferFromGenericFunctionReturnTypes1.js
 create mode 100644 tests/baselines/reference/inferFromGenericFunctionReturnTypes2.js
 create mode 100644 tests/baselines/reference/inferFromGenericFunctionReturnTypes2.symbols
 create mode 100644 tests/baselines/reference/inferFromGenericFunctionReturnTypes2.types

diff --git a/tests/baselines/reference/inferFromGenericFunctionReturnTypes1.errors.txt b/tests/baselines/reference/inferFromGenericFunctionReturnTypes1.errors.txt
new file mode 100644
index 00000000000..4ed8bdd81c6
--- /dev/null
+++ b/tests/baselines/reference/inferFromGenericFunctionReturnTypes1.errors.txt
@@ -0,0 +1,77 @@
+tests/cases/compiler/inferFromGenericFunctionReturnTypes1.ts(68,16): error TS2339: Property 'toUpperCase' does not exist on type 'number'.
+
+
+==== tests/cases/compiler/inferFromGenericFunctionReturnTypes1.ts (1 errors) ====
+    // Repro from #15680
+    
+    // This is a contrived class. We could do the same thing with Observables, etc.
+    class SetOf<A> {
+      _store: A[];
+    
+      add(a: A) {
+        this._store.push(a);
+      }
+    
+      transform<B>(transformer: (a: SetOf<A>) => SetOf<B>): SetOf<B> {
+        return transformer(this);
+      }
+    
+      forEach(fn: (a: A, index: number) => void) {
+          this._store.forEach((a, i) => fn(a, i));
+      }
+    }
+    
+    function compose<A, B, C, D, E>(
+      fnA: (a: SetOf<A>) => SetOf<B>, 
+      fnB: (b: SetOf<B>) => SetOf<C>, 
+      fnC: (c: SetOf<C>) => SetOf<D>,
+      fnD: (c: SetOf<D>) => SetOf<E>,
+    ):(x: SetOf<A>) => SetOf<E>;
+    /* ... etc ... */
+    function compose<T>(...fns: ((x: T) => T)[]): (x: T) => T {
+      return (x: T) => fns.reduce((prev, fn) => fn(prev), x);
+    }
+    
+    function map<A, B>(fn: (a: A) => B): (s: SetOf<A>) => SetOf<B> {
+      return (a: SetOf<A>) => {
+        const b: SetOf<B> = new SetOf();
+        a.forEach(x => b.add(fn(x)));
+        return b;
+      }
+    }
+    
+    function filter<A>(predicate: (a: A) => boolean): (s: SetOf<A>) => SetOf<A> {
+      return (a: SetOf<A>) => {
+        const result = new SetOf<A>();
+        a.forEach(x => {
+          if (predicate(x)) result.add(x);
+        });
+       return result;
+      }
+    }
+    
+    const testSet = new SetOf<number>();
+    testSet.add(1);
+    testSet.add(2);
+    testSet.add(3);
+    
+    testSet.transform(
+      compose(
+        filter(x => x % 1 === 0),
+        map(x => x + x),
+        map(x => x + '!!!'),
+        map(x => x.toUpperCase())
+      )
+    )
+    
+    testSet.transform(
+      compose(
+        filter(x => x % 1 === 0),
+        map(x => x + x),
+        map(x => 123),  // Whoops a bug
+        map(x => x.toUpperCase()) // causes an error!
+                   ~~~~~~~~~~~
+!!! error TS2339: Property 'toUpperCase' does not exist on type 'number'.
+      )
+    )
+    
\ No newline at end of file
diff --git a/tests/baselines/reference/inferFromGenericFunctionReturnTypes1.js b/tests/baselines/reference/inferFromGenericFunctionReturnTypes1.js
new file mode 100644
index 00000000000..0c3cf4b0cbe
--- /dev/null
+++ b/tests/baselines/reference/inferFromGenericFunctionReturnTypes1.js
@@ -0,0 +1,123 @@
+//// [inferFromGenericFunctionReturnTypes1.ts]
+// Repro from #15680
+
+// This is a contrived class. We could do the same thing with Observables, etc.
+class SetOf<A> {
+  _store: A[];
+
+  add(a: A) {
+    this._store.push(a);
+  }
+
+  transform<B>(transformer: (a: SetOf<A>) => SetOf<B>): SetOf<B> {
+    return transformer(this);
+  }
+
+  forEach(fn: (a: A, index: number) => void) {
+      this._store.forEach((a, i) => fn(a, i));
+  }
+}
+
+function compose<A, B, C, D, E>(
+  fnA: (a: SetOf<A>) => SetOf<B>, 
+  fnB: (b: SetOf<B>) => SetOf<C>, 
+  fnC: (c: SetOf<C>) => SetOf<D>,
+  fnD: (c: SetOf<D>) => SetOf<E>,
+):(x: SetOf<A>) => SetOf<E>;
+/* ... etc ... */
+function compose<T>(...fns: ((x: T) => T)[]): (x: T) => T {
+  return (x: T) => fns.reduce((prev, fn) => fn(prev), x);
+}
+
+function map<A, B>(fn: (a: A) => B): (s: SetOf<A>) => SetOf<B> {
+  return (a: SetOf<A>) => {
+    const b: SetOf<B> = new SetOf();
+    a.forEach(x => b.add(fn(x)));
+    return b;
+  }
+}
+
+function filter<A>(predicate: (a: A) => boolean): (s: SetOf<A>) => SetOf<A> {
+  return (a: SetOf<A>) => {
+    const result = new SetOf<A>();
+    a.forEach(x => {
+      if (predicate(x)) result.add(x);
+    });
+   return result;
+  }
+}
+
+const testSet = new SetOf<number>();
+testSet.add(1);
+testSet.add(2);
+testSet.add(3);
+
+testSet.transform(
+  compose(
+    filter(x => x % 1 === 0),
+    map(x => x + x),
+    map(x => x + '!!!'),
+    map(x => x.toUpperCase())
+  )
+)
+
+testSet.transform(
+  compose(
+    filter(x => x % 1 === 0),
+    map(x => x + x),
+    map(x => 123),  // Whoops a bug
+    map(x => x.toUpperCase()) // causes an error!
+  )
+)
+
+
+//// [inferFromGenericFunctionReturnTypes1.js]
+// Repro from #15680
+// This is a contrived class. We could do the same thing with Observables, etc.
+var SetOf = (function () {
+    function SetOf() {
+    }
+    SetOf.prototype.add = function (a) {
+        this._store.push(a);
+    };
+    SetOf.prototype.transform = function (transformer) {
+        return transformer(this);
+    };
+    SetOf.prototype.forEach = function (fn) {
+        this._store.forEach(function (a, i) { return fn(a, i); });
+    };
+    return SetOf;
+}());
+/* ... etc ... */
+function compose() {
+    var fns = [];
+    for (var _i = 0; _i < arguments.length; _i++) {
+        fns[_i] = arguments[_i];
+    }
+    return function (x) { return fns.reduce(function (prev, fn) { return fn(prev); }, x); };
+}
+function map(fn) {
+    return function (a) {
+        var b = new SetOf();
+        a.forEach(function (x) { return b.add(fn(x)); });
+        return b;
+    };
+}
+function filter(predicate) {
+    return function (a) {
+        var result = new SetOf();
+        a.forEach(function (x) {
+            if (predicate(x))
+                result.add(x);
+        });
+        return result;
+    };
+}
+var testSet = new SetOf();
+testSet.add(1);
+testSet.add(2);
+testSet.add(3);
+testSet.transform(compose(filter(function (x) { return x % 1 === 0; }), map(function (x) { return x + x; }), map(function (x) { return x + '!!!'; }), map(function (x) { return x.toUpperCase(); })));
+testSet.transform(compose(filter(function (x) { return x % 1 === 0; }), map(function (x) { return x + x; }), map(function (x) { return 123; }), // Whoops a bug
+map(function (x) { return x.toUpperCase(); }) // causes an error!
+));
diff --git a/tests/baselines/reference/inferFromGenericFunctionReturnTypes2.js b/tests/baselines/reference/inferFromGenericFunctionReturnTypes2.js
new file mode 100644
index 00000000000..3f95b10d08a
--- /dev/null
+++ b/tests/baselines/reference/inferFromGenericFunctionReturnTypes2.js
@@ -0,0 +1,155 @@
+//// [inferFromGenericFunctionReturnTypes2.ts]
+type Mapper<T, U> = (x: T) => U;
+
+declare function wrap<T, U>(cb: Mapper<T, U>): Mapper<T, U>;
+
+declare function arrayize<T, U>(cb: Mapper<T, U>): Mapper<T, U[]>;
+
+declare function combine<A, B, C>(f: (x: A) => B, g: (x: B) => C): (x: A) => C;
+
+declare function foo(f: Mapper<string, number>): void;
+
+let f1: Mapper<string, number> = s => s.length;
+let f2: Mapper<string, number> = wrap(s => s.length);
+let f3: Mapper<string, number[]> = arrayize(wrap(s => s.length));
+let f4: Mapper<string, boolean> = combine(wrap(s => s.length), wrap(n => n >= 10));
+
+foo(wrap(s => s.length));
+
+let a1 = ["a", "b"].map(s => s.length);
+let a2 = ["a", "b"].map(wrap(s => s.length));
+let a3 = ["a", "b"].map(wrap(arrayize(s => s.length)));
+let a4 = ["a", "b"].map(combine(wrap(s => s.length), wrap(n => n > 10)));
+let a5 = ["a", "b"].map(combine(identity, wrap(s => s.length)));
+let a6 = ["a", "b"].map(combine(wrap(s => s.length), identity));
+
+// This is a contrived class. We could do the same thing with Observables, etc.
+class SetOf<A> {
+  _store: A[];
+
+  add(a: A) {
+    this._store.push(a);
+  }
+
+  transform<B>(transformer: (a: SetOf<A>) => SetOf<B>): SetOf<B> {
+    return transformer(this);
+  }
+
+  forEach(fn: (a: A, index: number) => void) {
+      this._store.forEach((a, i) => fn(a, i));
+  }
+}
+
+function compose<A, B, C, D, E>(
+  fnA: (a: SetOf<A>) => SetOf<B>, 
+  fnB: (b: SetOf<B>) => SetOf<C>, 
+  fnC: (c: SetOf<C>) => SetOf<D>,
+  fnD: (c: SetOf<D>) => SetOf<E>,
+):(x: SetOf<A>) => SetOf<E>;
+/* ... etc ... */
+function compose<T>(...fns: ((x: T) => T)[]): (x: T) => T {
+  return (x: T) => fns.reduce((prev, fn) => fn(prev), x);
+}
+
+function map<A, B>(fn: (a: A) => B): (s: SetOf<A>) => SetOf<B> {
+  return (a: SetOf<A>) => {
+    const b: SetOf<B> = new SetOf();
+    a.forEach(x => b.add(fn(x)));
+    return b;
+  }
+}
+
+function filter<A>(predicate: (a: A) => boolean): (s: SetOf<A>) => SetOf<A> {
+  return (a: SetOf<A>) => {
+    const result = new SetOf<A>();
+    a.forEach(x => {
+      if (predicate(x)) result.add(x);
+    });
+   return result;
+  }
+}
+
+const testSet = new SetOf<number>();
+testSet.add(1);
+testSet.add(2);
+testSet.add(3);
+
+const t1 = testSet.transform(
+  compose(
+    filter(x => x % 1 === 0),
+    map(x => x + x),
+    map(x => x + '!!!'),
+    map(x => x.toUpperCase())
+  )
+)
+
+declare function identity<T>(x: T): T;
+
+const t2 = testSet.transform(
+  compose(
+    filter(x => x % 1 === 0),
+    identity,
+    map(x => x + '!!!'),
+    map(x => x.toUpperCase())
+  )
+)
+
+
+//// [inferFromGenericFunctionReturnTypes2.js]
+var f1 = function (s) { return s.length; };
+var f2 = wrap(function (s) { return s.length; });
+var f3 = arrayize(wrap(function (s) { return s.length; }));
+var f4 = combine(wrap(function (s) { return s.length; }), wrap(function (n) { return n >= 10; }));
+foo(wrap(function (s) { return s.length; }));
+var a1 = ["a", "b"].map(function (s) { return s.length; });
+var a2 = ["a", "b"].map(wrap(function (s) { return s.length; }));
+var a3 = ["a", "b"].map(wrap(arrayize(function (s) { return s.length; })));
+var a4 = ["a", "b"].map(combine(wrap(function (s) { return s.length; }), wrap(function (n) { return n > 10; })));
+var a5 = ["a", "b"].map(combine(identity, wrap(function (s) { return s.length; })));
+var a6 = ["a", "b"].map(combine(wrap(function (s) { return s.length; }), identity));
+// This is a contrived class. We could do the same thing with Observables, etc.
+var SetOf = (function () {
+    function SetOf() {
+    }
+    SetOf.prototype.add = function (a) {
+        this._store.push(a);
+    };
+    SetOf.prototype.transform = function (transformer) {
+        return transformer(this);
+    };
+    SetOf.prototype.forEach = function (fn) {
+        this._store.forEach(function (a, i) { return fn(a, i); });
+    };
+    return SetOf;
+}());
+/* ... etc ... */
+function compose() {
+    var fns = [];
+    for (var _i = 0; _i < arguments.length; _i++) {
+        fns[_i] = arguments[_i];
+    }
+    return function (x) { return fns.reduce(function (prev, fn) { return fn(prev); }, x); };
+}
+function map(fn) {
+    return function (a) {
+        var b = new SetOf();
+        a.forEach(function (x) { return b.add(fn(x)); });
+        return b;
+    };
+}
+function filter(predicate) {
+    return function (a) {
+        var result = new SetOf();
+        a.forEach(function (x) {
+            if (predicate(x))
+                result.add(x);
+        });
+        return result;
+    };
+}
+var testSet = new SetOf();
+testSet.add(1);
+testSet.add(2);
+testSet.add(3);
+var t1 = testSet.transform(compose(filter(function (x) { return x % 1 === 0; }), map(function (x) { return x + x; }), map(function (x) { return x + '!!!'; }), map(function (x) { return x.toUpperCase(); })));
+var t2 = testSet.transform(compose(filter(function (x) { return x % 1 === 0; }), identity, map(function (x) { return x + '!!!'; }), map(function (x) { return x.toUpperCase(); })));
diff --git a/tests/baselines/reference/inferFromGenericFunctionReturnTypes2.symbols b/tests/baselines/reference/inferFromGenericFunctionReturnTypes2.symbols
new file mode 100644
index 00000000000..79a855badb5
--- /dev/null
+++ b/tests/baselines/reference/inferFromGenericFunctionReturnTypes2.symbols
@@ -0,0 +1,480 @@
+=== tests/cases/compiler/inferFromGenericFunctionReturnTypes2.ts ===
+type Mapper<T, U> = (x: T) => U;
+>Mapper : Symbol(Mapper, Decl(inferFromGenericFunctionReturnTypes2.ts, 0, 0))
+>T : Symbol(T, Decl(inferFromGenericFunctionReturnTypes2.ts, 0, 12))
+>U : Symbol(U, Decl(inferFromGenericFunctionReturnTypes2.ts, 0, 14))
+>x : Symbol(x, Decl(inferFromGenericFunctionReturnTypes2.ts, 0, 21))
+>T : Symbol(T, Decl(inferFromGenericFunctionReturnTypes2.ts, 0, 12))
+>U : Symbol(U, Decl(inferFromGenericFunctionReturnTypes2.ts, 0, 14))
+
+declare function wrap<T, U>(cb: Mapper<T, U>): Mapper<T, U>;
+>wrap : Symbol(wrap, Decl(inferFromGenericFunctionReturnTypes2.ts, 0, 32))
+>T : Symbol(T, Decl(inferFromGenericFunctionReturnTypes2.ts, 2, 22))
+>U : Symbol(U, Decl(inferFromGenericFunctionReturnTypes2.ts, 2, 24))
+>cb : Symbol(cb, Decl(inferFromGenericFunctionReturnTypes2.ts, 2, 28))
+>Mapper : Symbol(Mapper, Decl(inferFromGenericFunctionReturnTypes2.ts, 0, 0))
+>T : Symbol(T, Decl(inferFromGenericFunctionReturnTypes2.ts, 2, 22))
+>U : Symbol(U, Decl(inferFromGenericFunctionReturnTypes2.ts, 2, 24))
+>Mapper : Symbol(Mapper, Decl(inferFromGenericFunctionReturnTypes2.ts, 0, 0))
+>T : Symbol(T, Decl(inferFromGenericFunctionReturnTypes2.ts, 2, 22))
+>U : Symbol(U, Decl(inferFromGenericFunctionReturnTypes2.ts, 2, 24))
+
+declare function arrayize<T, U>(cb: Mapper<T, U>): Mapper<T, U[]>;
+>arrayize : Symbol(arrayize, Decl(inferFromGenericFunctionReturnTypes2.ts, 2, 60))
+>T : Symbol(T, Decl(inferFromGenericFunctionReturnTypes2.ts, 4, 26))
+>U : Symbol(U, Decl(inferFromGenericFunctionReturnTypes2.ts, 4, 28))
+>cb : Symbol(cb, Decl(inferFromGenericFunctionReturnTypes2.ts, 4, 32))
+>Mapper : Symbol(Mapper, Decl(inferFromGenericFunctionReturnTypes2.ts, 0, 0))
+>T : Symbol(T, Decl(inferFromGenericFunctionReturnTypes2.ts, 4, 26))
+>U : Symbol(U, Decl(inferFromGenericFunctionReturnTypes2.ts, 4, 28))
+>Mapper : Symbol(Mapper, Decl(inferFromGenericFunctionReturnTypes2.ts, 0, 0))
+>T : Symbol(T, Decl(inferFromGenericFunctionReturnTypes2.ts, 4, 26))
+>U : Symbol(U, Decl(inferFromGenericFunctionReturnTypes2.ts, 4, 28))
+
+declare function combine<A, B, C>(f: (x: A) => B, g: (x: B) => C): (x: A) => C;
+>combine : Symbol(combine, Decl(inferFromGenericFunctionReturnTypes2.ts, 4, 66))
+>A : Symbol(A, Decl(inferFromGenericFunctionReturnTypes2.ts, 6, 25))
+>B : Symbol(B, Decl(inferFromGenericFunctionReturnTypes2.ts, 6, 27))
+>C : Symbol(C, Decl(inferFromGenericFunctionReturnTypes2.ts, 6, 30))
+>f : Symbol(f, Decl(inferFromGenericFunctionReturnTypes2.ts, 6, 34))
+>x : Symbol(x, Decl(inferFromGenericFunctionReturnTypes2.ts, 6, 38))
+>A : Symbol(A, Decl(inferFromGenericFunctionReturnTypes2.ts, 6, 25))
+>B : Symbol(B, Decl(inferFromGenericFunctionReturnTypes2.ts, 6, 27))
+>g : Symbol(g, Decl(inferFromGenericFunctionReturnTypes2.ts, 6, 49))
+>x : Symbol(x, Decl(inferFromGenericFunctionReturnTypes2.ts, 6, 54))
+>B : Symbol(B, Decl(inferFromGenericFunctionReturnTypes2.ts, 6, 27))
+>C : Symbol(C, Decl(inferFromGenericFunctionReturnTypes2.ts, 6, 30))
+>x : Symbol(x, Decl(inferFromGenericFunctionReturnTypes2.ts, 6, 68))
+>A : Symbol(A, Decl(inferFromGenericFunctionReturnTypes2.ts, 6, 25))
+>C : Symbol(C, Decl(inferFromGenericFunctionReturnTypes2.ts, 6, 30))
+
+declare function foo(f: Mapper<string, number>): void;
+>foo : Symbol(foo, Decl(inferFromGenericFunctionReturnTypes2.ts, 6, 79))
+>f : Symbol(f, Decl(inferFromGenericFunctionReturnTypes2.ts, 8, 21))
+>Mapper : Symbol(Mapper, Decl(inferFromGenericFunctionReturnTypes2.ts, 0, 0))
+
+let f1: Mapper<string, number> = s => s.length;
+>f1 : Symbol(f1, Decl(inferFromGenericFunctionReturnTypes2.ts, 10, 3))
+>Mapper : Symbol(Mapper, Decl(inferFromGenericFunctionReturnTypes2.ts, 0, 0))
+>s : Symbol(s, Decl(inferFromGenericFunctionReturnTypes2.ts, 10, 32))
+>s.length : Symbol(String.length, Decl(lib.d.ts, --, --))
+>s : Symbol(s, Decl(inferFromGenericFunctionReturnTypes2.ts, 10, 32))
+>length : Symbol(String.length, Decl(lib.d.ts, --, --))
+
+let f2: Mapper<string, number> = wrap(s => s.length);
+>f2 : Symbol(f2, Decl(inferFromGenericFunctionReturnTypes2.ts, 11, 3))
+>Mapper : Symbol(Mapper, Decl(inferFromGenericFunctionReturnTypes2.ts, 0, 0))
+>wrap : Symbol(wrap, Decl(inferFromGenericFunctionReturnTypes2.ts, 0, 32))
+>s : Symbol(s, Decl(inferFromGenericFunctionReturnTypes2.ts, 11, 38))
+>s.length : Symbol(String.length, Decl(lib.d.ts, --, --))
+>s : Symbol(s, Decl(inferFromGenericFunctionReturnTypes2.ts, 11, 38))
+>length : Symbol(String.length, Decl(lib.d.ts, --, --))
+
+let f3: Mapper<string, number[]> = arrayize(wrap(s => s.length));
+>f3 : Symbol(f3, Decl(inferFromGenericFunctionReturnTypes2.ts, 12, 3))
+>Mapper : Symbol(Mapper, Decl(inferFromGenericFunctionReturnTypes2.ts, 0, 0))
+>arrayize : Symbol(arrayize, Decl(inferFromGenericFunctionReturnTypes2.ts, 2, 60))
+>wrap : Symbol(wrap, Decl(inferFromGenericFunctionReturnTypes2.ts, 0, 32))
+>s : Symbol(s, Decl(inferFromGenericFunctionReturnTypes2.ts, 12, 49))
+>s.length : Symbol(String.length, Decl(lib.d.ts, --, --))
+>s : Symbol(s, Decl(inferFromGenericFunctionReturnTypes2.ts, 12, 49))
+>length : Symbol(String.length, Decl(lib.d.ts, --, --))
+
+let f4: Mapper<string, boolean> = combine(wrap(s => s.length), wrap(n => n >= 10));
+>f4 : Symbol(f4, Decl(inferFromGenericFunctionReturnTypes2.ts, 13, 3))
+>Mapper : Symbol(Mapper, Decl(inferFromGenericFunctionReturnTypes2.ts, 0, 0))
+>combine : Symbol(combine, Decl(inferFromGenericFunctionReturnTypes2.ts, 4, 66))
+>wrap : Symbol(wrap, Decl(inferFromGenericFunctionReturnTypes2.ts, 0, 32))
+>s : Symbol(s, Decl(inferFromGenericFunctionReturnTypes2.ts, 13, 47))
+>s.length : Symbol(String.length, Decl(lib.d.ts, --, --))
+>s : Symbol(s, Decl(inferFromGenericFunctionReturnTypes2.ts, 13, 47))
+>length : Symbol(String.length, Decl(lib.d.ts, --, --))
+>wrap : Symbol(wrap, Decl(inferFromGenericFunctionReturnTypes2.ts, 0, 32))
+>n : Symbol(n, Decl(inferFromGenericFunctionReturnTypes2.ts, 13, 68))
+>n : Symbol(n, Decl(inferFromGenericFunctionReturnTypes2.ts, 13, 68))
+
+foo(wrap(s => s.length));
+>foo : Symbol(foo, Decl(inferFromGenericFunctionReturnTypes2.ts, 6, 79))
+>wrap : Symbol(wrap, Decl(inferFromGenericFunctionReturnTypes2.ts, 0, 32))
+>s : Symbol(s, Decl(inferFromGenericFunctionReturnTypes2.ts, 15, 9))
+>s.length : Symbol(String.length, Decl(lib.d.ts, --, --))
+>s : Symbol(s, Decl(inferFromGenericFunctionReturnTypes2.ts, 15, 9))
+>length : Symbol(String.length, Decl(lib.d.ts, --, --))
+
+let a1 = ["a", "b"].map(s => s.length);
+>a1 : Symbol(a1, Decl(inferFromGenericFunctionReturnTypes2.ts, 17, 3))
+>["a", "b"].map : Symbol(Array.map, Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --))
+>map : Symbol(Array.map, Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --))
+>s : Symbol(s, Decl(inferFromGenericFunctionReturnTypes2.ts, 17, 24))
+>s.length : Symbol(String.length, Decl(lib.d.ts, --, --))
+>s : Symbol(s, Decl(inferFromGenericFunctionReturnTypes2.ts, 17, 24))
+>length : Symbol(String.length, Decl(lib.d.ts, --, --))
+
+let a2 = ["a", "b"].map(wrap(s => s.length));
+>a2 : Symbol(a2, Decl(inferFromGenericFunctionReturnTypes2.ts, 18, 3))
+>["a", "b"].map : Symbol(Array.map, Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --))
+>map : Symbol(Array.map, Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --))
+>wrap : Symbol(wrap, Decl(inferFromGenericFunctionReturnTypes2.ts, 0, 32))
+>s : Symbol(s, Decl(inferFromGenericFunctionReturnTypes2.ts, 18, 29))
+>s.length : Symbol(String.length, Decl(lib.d.ts, --, --))
+>s : Symbol(s, Decl(inferFromGenericFunctionReturnTypes2.ts, 18, 29))
+>length : Symbol(String.length, Decl(lib.d.ts, --, --))
+
+let a3 = ["a", "b"].map(wrap(arrayize(s => s.length)));
+>a3 : Symbol(a3, Decl(inferFromGenericFunctionReturnTypes2.ts, 19, 3))
+>["a", "b"].map : Symbol(Array.map, Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --))
+>map : Symbol(Array.map, Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --))
+>wrap : Symbol(wrap, Decl(inferFromGenericFunctionReturnTypes2.ts, 0, 32))
+>arrayize : Symbol(arrayize, Decl(inferFromGenericFunctionReturnTypes2.ts, 2, 60))
+>s : Symbol(s, Decl(inferFromGenericFunctionReturnTypes2.ts, 19, 38))
+>s.length : Symbol(String.length, Decl(lib.d.ts, --, --))
+>s : Symbol(s, Decl(inferFromGenericFunctionReturnTypes2.ts, 19, 38))
+>length : Symbol(String.length, Decl(lib.d.ts, --, --))
+
+let a4 = ["a", "b"].map(combine(wrap(s => s.length), wrap(n => n > 10)));
+>a4 : Symbol(a4, Decl(inferFromGenericFunctionReturnTypes2.ts, 20, 3))
+>["a", "b"].map : Symbol(Array.map, Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --))
+>map : Symbol(Array.map, Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --))
+>combine : Symbol(combine, Decl(inferFromGenericFunctionReturnTypes2.ts, 4, 66))
+>wrap : Symbol(wrap, Decl(inferFromGenericFunctionReturnTypes2.ts, 0, 32))
+>s : Symbol(s, Decl(inferFromGenericFunctionReturnTypes2.ts, 20, 37))
+>s.length : Symbol(String.length, Decl(lib.d.ts, --, --))
+>s : Symbol(s, Decl(inferFromGenericFunctionReturnTypes2.ts, 20, 37))
+>length : Symbol(String.length, Decl(lib.d.ts, --, --))
+>wrap : Symbol(wrap, Decl(inferFromGenericFunctionReturnTypes2.ts, 0, 32))
+>n : Symbol(n, Decl(inferFromGenericFunctionReturnTypes2.ts, 20, 58))
+>n : Symbol(n, Decl(inferFromGenericFunctionReturnTypes2.ts, 20, 58))
+
+let a5 = ["a", "b"].map(combine(identity, wrap(s => s.length)));
+>a5 : Symbol(a5, Decl(inferFromGenericFunctionReturnTypes2.ts, 21, 3))
+>["a", "b"].map : Symbol(Array.map, Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --))
+>map : Symbol(Array.map, Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --))
+>combine : Symbol(combine, Decl(inferFromGenericFunctionReturnTypes2.ts, 4, 66))
+>identity : Symbol(identity, Decl(inferFromGenericFunctionReturnTypes2.ts, 82, 1))
+>wrap : Symbol(wrap, Decl(inferFromGenericFunctionReturnTypes2.ts, 0, 32))
+>s : Symbol(s, Decl(inferFromGenericFunctionReturnTypes2.ts, 21, 47))
+>s.length : Symbol(String.length, Decl(lib.d.ts, --, --))
+>s : Symbol(s, Decl(inferFromGenericFunctionReturnTypes2.ts, 21, 47))
+>length : Symbol(String.length, Decl(lib.d.ts, --, --))
+
+let a6 = ["a", "b"].map(combine(wrap(s => s.length), identity));
+>a6 : Symbol(a6, Decl(inferFromGenericFunctionReturnTypes2.ts, 22, 3))
+>["a", "b"].map : Symbol(Array.map, Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --))
+>map : Symbol(Array.map, Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --))
+>combine : Symbol(combine, Decl(inferFromGenericFunctionReturnTypes2.ts, 4, 66))
+>wrap : Symbol(wrap, Decl(inferFromGenericFunctionReturnTypes2.ts, 0, 32))
+>s : Symbol(s, Decl(inferFromGenericFunctionReturnTypes2.ts, 22, 37))
+>s.length : Symbol(String.length, Decl(lib.d.ts, --, --))
+>s : Symbol(s, Decl(inferFromGenericFunctionReturnTypes2.ts, 22, 37))
+>length : Symbol(String.length, Decl(lib.d.ts, --, --))
+>identity : Symbol(identity, Decl(inferFromGenericFunctionReturnTypes2.ts, 82, 1))
+
+// This is a contrived class. We could do the same thing with Observables, etc.
+class SetOf<A> {
+>SetOf : Symbol(SetOf, Decl(inferFromGenericFunctionReturnTypes2.ts, 22, 64))
+>A : Symbol(A, Decl(inferFromGenericFunctionReturnTypes2.ts, 25, 12))
+
+  _store: A[];
+>_store : Symbol(SetOf._store, Decl(inferFromGenericFunctionReturnTypes2.ts, 25, 16))
+>A : Symbol(A, Decl(inferFromGenericFunctionReturnTypes2.ts, 25, 12))
+
+  add(a: A) {
+>add : Symbol(SetOf.add, Decl(inferFromGenericFunctionReturnTypes2.ts, 26, 14))
+>a : Symbol(a, Decl(inferFromGenericFunctionReturnTypes2.ts, 28, 6))
+>A : Symbol(A, Decl(inferFromGenericFunctionReturnTypes2.ts, 25, 12))
+
+    this._store.push(a);
+>this._store.push : Symbol(Array.push, Decl(lib.d.ts, --, --))
+>this._store : Symbol(SetOf._store, Decl(inferFromGenericFunctionReturnTypes2.ts, 25, 16))
+>this : Symbol(SetOf, Decl(inferFromGenericFunctionReturnTypes2.ts, 22, 64))
+>_store : Symbol(SetOf._store, Decl(inferFromGenericFunctionReturnTypes2.ts, 25, 16))
+>push : Symbol(Array.push, Decl(lib.d.ts, --, --))
+>a : Symbol(a, Decl(inferFromGenericFunctionReturnTypes2.ts, 28, 6))
+  }
+
+  transform<B>(transformer: (a: SetOf<A>) => SetOf<B>): SetOf<B> {
+>transform : Symbol(SetOf.transform, Decl(inferFromGenericFunctionReturnTypes2.ts, 30, 3))
+>B : Symbol(B, Decl(inferFromGenericFunctionReturnTypes2.ts, 32, 12))
+>transformer : Symbol(transformer, Decl(inferFromGenericFunctionReturnTypes2.ts, 32, 15))
+>a : Symbol(a, Decl(inferFromGenericFunctionReturnTypes2.ts, 32, 29))
+>SetOf : Symbol(SetOf, Decl(inferFromGenericFunctionReturnTypes2.ts, 22, 64))
+>A : Symbol(A, Decl(inferFromGenericFunctionReturnTypes2.ts, 25, 12))
+>SetOf : Symbol(SetOf, Decl(inferFromGenericFunctionReturnTypes2.ts, 22, 64))
+>B : Symbol(B, Decl(inferFromGenericFunctionReturnTypes2.ts, 32, 12))
+>SetOf : Symbol(SetOf, Decl(inferFromGenericFunctionReturnTypes2.ts, 22, 64))
+>B : Symbol(B, Decl(inferFromGenericFunctionReturnTypes2.ts, 32, 12))
+
+    return transformer(this);
+>transformer : Symbol(transformer, Decl(inferFromGenericFunctionReturnTypes2.ts, 32, 15))
+>this : Symbol(SetOf, Decl(inferFromGenericFunctionReturnTypes2.ts, 22, 64))
+  }
+
+  forEach(fn: (a: A, index: number) => void) {
+>forEach : Symbol(SetOf.forEach, Decl(inferFromGenericFunctionReturnTypes2.ts, 34, 3))
+>fn : Symbol(fn, Decl(inferFromGenericFunctionReturnTypes2.ts, 36, 10))
+>a : Symbol(a, Decl(inferFromGenericFunctionReturnTypes2.ts, 36, 15))
+>A : Symbol(A, Decl(inferFromGenericFunctionReturnTypes2.ts, 25, 12))
+>index : Symbol(index, Decl(inferFromGenericFunctionReturnTypes2.ts, 36, 20))
+
+      this._store.forEach((a, i) => fn(a, i));
+>this._store.forEach : Symbol(Array.forEach, Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --))
+>this._store : Symbol(SetOf._store, Decl(inferFromGenericFunctionReturnTypes2.ts, 25, 16))
+>this : Symbol(SetOf, Decl(inferFromGenericFunctionReturnTypes2.ts, 22, 64))
+>_store : Symbol(SetOf._store, Decl(inferFromGenericFunctionReturnTypes2.ts, 25, 16))
+>forEach : Symbol(Array.forEach, Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --))
+>a : Symbol(a, Decl(inferFromGenericFunctionReturnTypes2.ts, 37, 27))
+>i : Symbol(i, Decl(inferFromGenericFunctionReturnTypes2.ts, 37, 29))
+>fn : Symbol(fn, Decl(inferFromGenericFunctionReturnTypes2.ts, 36, 10))
+>a : Symbol(a, Decl(inferFromGenericFunctionReturnTypes2.ts, 37, 27))
+>i : Symbol(i, Decl(inferFromGenericFunctionReturnTypes2.ts, 37, 29))
+  }
+}
+
+function compose<A, B, C, D, E>(
+>compose : Symbol(compose, Decl(inferFromGenericFunctionReturnTypes2.ts, 39, 1), Decl(inferFromGenericFunctionReturnTypes2.ts, 46, 28))
+>A : Symbol(A, Decl(inferFromGenericFunctionReturnTypes2.ts, 41, 17))
+>B : Symbol(B, Decl(inferFromGenericFunctionReturnTypes2.ts, 41, 19))
+>C : Symbol(C, Decl(inferFromGenericFunctionReturnTypes2.ts, 41, 22))
+>D : Symbol(D, Decl(inferFromGenericFunctionReturnTypes2.ts, 41, 25))
+>E : Symbol(E, Decl(inferFromGenericFunctionReturnTypes2.ts, 41, 28))
+
+  fnA: (a: SetOf<A>) => SetOf<B>, 
+>fnA : Symbol(fnA, Decl(inferFromGenericFunctionReturnTypes2.ts, 41, 32))
+>a : Symbol(a, Decl(inferFromGenericFunctionReturnTypes2.ts, 42, 8))
+>SetOf : Symbol(SetOf, Decl(inferFromGenericFunctionReturnTypes2.ts, 22, 64))
+>A : Symbol(A, Decl(inferFromGenericFunctionReturnTypes2.ts, 41, 17))
+>SetOf : Symbol(SetOf, Decl(inferFromGenericFunctionReturnTypes2.ts, 22, 64))
+>B : Symbol(B, Decl(inferFromGenericFunctionReturnTypes2.ts, 41, 19))
+
+  fnB: (b: SetOf<B>) => SetOf<C>, 
+>fnB : Symbol(fnB, Decl(inferFromGenericFunctionReturnTypes2.ts, 42, 33))
+>b : Symbol(b, Decl(inferFromGenericFunctionReturnTypes2.ts, 43, 8))
+>SetOf : Symbol(SetOf, Decl(inferFromGenericFunctionReturnTypes2.ts, 22, 64))
+>B : Symbol(B, Decl(inferFromGenericFunctionReturnTypes2.ts, 41, 19))
+>SetOf : Symbol(SetOf, Decl(inferFromGenericFunctionReturnTypes2.ts, 22, 64))
+>C : Symbol(C, Decl(inferFromGenericFunctionReturnTypes2.ts, 41, 22))
+
+  fnC: (c: SetOf<C>) => SetOf<D>,
+>fnC : Symbol(fnC, Decl(inferFromGenericFunctionReturnTypes2.ts, 43, 33))
+>c : Symbol(c, Decl(inferFromGenericFunctionReturnTypes2.ts, 44, 8))
+>SetOf : Symbol(SetOf, Decl(inferFromGenericFunctionReturnTypes2.ts, 22, 64))
+>C : Symbol(C, Decl(inferFromGenericFunctionReturnTypes2.ts, 41, 22))
+>SetOf : Symbol(SetOf, Decl(inferFromGenericFunctionReturnTypes2.ts, 22, 64))
+>D : Symbol(D, Decl(inferFromGenericFunctionReturnTypes2.ts, 41, 25))
+
+  fnD: (c: SetOf<D>) => SetOf<E>,
+>fnD : Symbol(fnD, Decl(inferFromGenericFunctionReturnTypes2.ts, 44, 33))
+>c : Symbol(c, Decl(inferFromGenericFunctionReturnTypes2.ts, 45, 8))
+>SetOf : Symbol(SetOf, Decl(inferFromGenericFunctionReturnTypes2.ts, 22, 64))
+>D : Symbol(D, Decl(inferFromGenericFunctionReturnTypes2.ts, 41, 25))
+>SetOf : Symbol(SetOf, Decl(inferFromGenericFunctionReturnTypes2.ts, 22, 64))
+>E : Symbol(E, Decl(inferFromGenericFunctionReturnTypes2.ts, 41, 28))
+
+):(x: SetOf<A>) => SetOf<E>;
+>x : Symbol(x, Decl(inferFromGenericFunctionReturnTypes2.ts, 46, 3))
+>SetOf : Symbol(SetOf, Decl(inferFromGenericFunctionReturnTypes2.ts, 22, 64))
+>A : Symbol(A, Decl(inferFromGenericFunctionReturnTypes2.ts, 41, 17))
+>SetOf : Symbol(SetOf, Decl(inferFromGenericFunctionReturnTypes2.ts, 22, 64))
+>E : Symbol(E, Decl(inferFromGenericFunctionReturnTypes2.ts, 41, 28))
+
+/* ... etc ... */
+function compose<T>(...fns: ((x: T) => T)[]): (x: T) => T {
+>compose : Symbol(compose, Decl(inferFromGenericFunctionReturnTypes2.ts, 39, 1), Decl(inferFromGenericFunctionReturnTypes2.ts, 46, 28))
+>T : Symbol(T, Decl(inferFromGenericFunctionReturnTypes2.ts, 48, 17))
+>fns : Symbol(fns, Decl(inferFromGenericFunctionReturnTypes2.ts, 48, 20))
+>x : Symbol(x, Decl(inferFromGenericFunctionReturnTypes2.ts, 48, 30))
+>T : Symbol(T, Decl(inferFromGenericFunctionReturnTypes2.ts, 48, 17))
+>T : Symbol(T, Decl(inferFromGenericFunctionReturnTypes2.ts, 48, 17))
+>x : Symbol(x, Decl(inferFromGenericFunctionReturnTypes2.ts, 48, 47))
+>T : Symbol(T, Decl(inferFromGenericFunctionReturnTypes2.ts, 48, 17))
+>T : Symbol(T, Decl(inferFromGenericFunctionReturnTypes2.ts, 48, 17))
+
+  return (x: T) => fns.reduce((prev, fn) => fn(prev), x);
+>x : Symbol(x, Decl(inferFromGenericFunctionReturnTypes2.ts, 49, 10))
+>T : Symbol(T, Decl(inferFromGenericFunctionReturnTypes2.ts, 48, 17))
+>fns.reduce : Symbol(Array.reduce, Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --))
+>fns : Symbol(fns, Decl(inferFromGenericFunctionReturnTypes2.ts, 48, 20))
+>reduce : Symbol(Array.reduce, Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --))
+>prev : Symbol(prev, Decl(inferFromGenericFunctionReturnTypes2.ts, 49, 31))
+>fn : Symbol(fn, Decl(inferFromGenericFunctionReturnTypes2.ts, 49, 36))
+>fn : Symbol(fn, Decl(inferFromGenericFunctionReturnTypes2.ts, 49, 36))
+>prev : Symbol(prev, Decl(inferFromGenericFunctionReturnTypes2.ts, 49, 31))
+>x : Symbol(x, Decl(inferFromGenericFunctionReturnTypes2.ts, 49, 10))
+}
+
+function map<A, B>(fn: (a: A) => B): (s: SetOf<A>) => SetOf<B> {
+>map : Symbol(map, Decl(inferFromGenericFunctionReturnTypes2.ts, 50, 1))
+>A : Symbol(A, Decl(inferFromGenericFunctionReturnTypes2.ts, 52, 13))
+>B : Symbol(B, Decl(inferFromGenericFunctionReturnTypes2.ts, 52, 15))
+>fn : Symbol(fn, Decl(inferFromGenericFunctionReturnTypes2.ts, 52, 19))
+>a : Symbol(a, Decl(inferFromGenericFunctionReturnTypes2.ts, 52, 24))
+>A : Symbol(A, Decl(inferFromGenericFunctionReturnTypes2.ts, 52, 13))
+>B : Symbol(B, Decl(inferFromGenericFunctionReturnTypes2.ts, 52, 15))
+>s : Symbol(s, Decl(inferFromGenericFunctionReturnTypes2.ts, 52, 38))
+>SetOf : Symbol(SetOf, Decl(inferFromGenericFunctionReturnTypes2.ts, 22, 64))
+>A : Symbol(A, Decl(inferFromGenericFunctionReturnTypes2.ts, 52, 13))
+>SetOf : Symbol(SetOf, Decl(inferFromGenericFunctionReturnTypes2.ts, 22, 64))
+>B : Symbol(B, Decl(inferFromGenericFunctionReturnTypes2.ts, 52, 15))
+
+  return (a: SetOf<A>) => {
+>a : Symbol(a, Decl(inferFromGenericFunctionReturnTypes2.ts, 53, 10))
+>SetOf : Symbol(SetOf, Decl(inferFromGenericFunctionReturnTypes2.ts, 22, 64))
+>A : Symbol(A, Decl(inferFromGenericFunctionReturnTypes2.ts, 52, 13))
+
+    const b: SetOf<B> = new SetOf();
+>b : Symbol(b, Decl(inferFromGenericFunctionReturnTypes2.ts, 54, 9))
+>SetOf : Symbol(SetOf, Decl(inferFromGenericFunctionReturnTypes2.ts, 22, 64))
+>B : Symbol(B, Decl(inferFromGenericFunctionReturnTypes2.ts, 52, 15))
+>SetOf : Symbol(SetOf, Decl(inferFromGenericFunctionReturnTypes2.ts, 22, 64))
+
+    a.forEach(x => b.add(fn(x)));
+>a.forEach : Symbol(SetOf.forEach, Decl(inferFromGenericFunctionReturnTypes2.ts, 34, 3))
+>a : Symbol(a, Decl(inferFromGenericFunctionReturnTypes2.ts, 53, 10))
+>forEach : Symbol(SetOf.forEach, Decl(inferFromGenericFunctionReturnTypes2.ts, 34, 3))
+>x : Symbol(x, Decl(inferFromGenericFunctionReturnTypes2.ts, 55, 14))
+>b.add : Symbol(SetOf.add, Decl(inferFromGenericFunctionReturnTypes2.ts, 26, 14))
+>b : Symbol(b, Decl(inferFromGenericFunctionReturnTypes2.ts, 54, 9))
+>add : Symbol(SetOf.add, Decl(inferFromGenericFunctionReturnTypes2.ts, 26, 14))
+>fn : Symbol(fn, Decl(inferFromGenericFunctionReturnTypes2.ts, 52, 19))
+>x : Symbol(x, Decl(inferFromGenericFunctionReturnTypes2.ts, 55, 14))
+
+    return b;
+>b : Symbol(b, Decl(inferFromGenericFunctionReturnTypes2.ts, 54, 9))
+  }
+}
+
+function filter<A>(predicate: (a: A) => boolean): (s: SetOf<A>) => SetOf<A> {
+>filter : Symbol(filter, Decl(inferFromGenericFunctionReturnTypes2.ts, 58, 1))
+>A : Symbol(A, Decl(inferFromGenericFunctionReturnTypes2.ts, 60, 16))
+>predicate : Symbol(predicate, Decl(inferFromGenericFunctionReturnTypes2.ts, 60, 19))
+>a : Symbol(a, Decl(inferFromGenericFunctionReturnTypes2.ts, 60, 31))
+>A : Symbol(A, Decl(inferFromGenericFunctionReturnTypes2.ts, 60, 16))
+>s : Symbol(s, Decl(inferFromGenericFunctionReturnTypes2.ts, 60, 51))
+>SetOf : Symbol(SetOf, Decl(inferFromGenericFunctionReturnTypes2.ts, 22, 64))
+>A : Symbol(A, Decl(inferFromGenericFunctionReturnTypes2.ts, 60, 16))
+>SetOf : Symbol(SetOf, Decl(inferFromGenericFunctionReturnTypes2.ts, 22, 64))
+>A : Symbol(A, Decl(inferFromGenericFunctionReturnTypes2.ts, 60, 16))
+
+  return (a: SetOf<A>) => {
+>a : Symbol(a, Decl(inferFromGenericFunctionReturnTypes2.ts, 61, 10))
+>SetOf : Symbol(SetOf, Decl(inferFromGenericFunctionReturnTypes2.ts, 22, 64))
+>A : Symbol(A, Decl(inferFromGenericFunctionReturnTypes2.ts, 60, 16))
+
+    const result = new SetOf<A>();
+>result : Symbol(result, Decl(inferFromGenericFunctionReturnTypes2.ts, 62, 9))
+>SetOf : Symbol(SetOf, Decl(inferFromGenericFunctionReturnTypes2.ts, 22, 64))
+>A : Symbol(A, Decl(inferFromGenericFunctionReturnTypes2.ts, 60, 16))
+
+    a.forEach(x => {
+>a.forEach : Symbol(SetOf.forEach, Decl(inferFromGenericFunctionReturnTypes2.ts, 34, 3))
+>a : Symbol(a, Decl(inferFromGenericFunctionReturnTypes2.ts, 61, 10))
+>forEach : Symbol(SetOf.forEach, Decl(inferFromGenericFunctionReturnTypes2.ts, 34, 3))
+>x : Symbol(x, Decl(inferFromGenericFunctionReturnTypes2.ts, 63, 14))
+
+      if (predicate(x)) result.add(x);
+>predicate : Symbol(predicate, Decl(inferFromGenericFunctionReturnTypes2.ts, 60, 19))
+>x : Symbol(x, Decl(inferFromGenericFunctionReturnTypes2.ts, 63, 14))
+>result.add : Symbol(SetOf.add, Decl(inferFromGenericFunctionReturnTypes2.ts, 26, 14))
+>result : Symbol(result, Decl(inferFromGenericFunctionReturnTypes2.ts, 62, 9))
+>add : Symbol(SetOf.add, Decl(inferFromGenericFunctionReturnTypes2.ts, 26, 14))
+>x : Symbol(x, Decl(inferFromGenericFunctionReturnTypes2.ts, 63, 14))
+
+    });
+   return result;
+>result : Symbol(result, Decl(inferFromGenericFunctionReturnTypes2.ts, 62, 9))
+  }
+}
+
+const testSet = new SetOf<number>();
+>testSet : Symbol(testSet, Decl(inferFromGenericFunctionReturnTypes2.ts, 70, 5))
+>SetOf : Symbol(SetOf, Decl(inferFromGenericFunctionReturnTypes2.ts, 22, 64))
+
+testSet.add(1);
+>testSet.add : Symbol(SetOf.add, Decl(inferFromGenericFunctionReturnTypes2.ts, 26, 14))
+>testSet : Symbol(testSet, Decl(inferFromGenericFunctionReturnTypes2.ts, 70, 5))
+>add : Symbol(SetOf.add, Decl(inferFromGenericFunctionReturnTypes2.ts, 26, 14))
+
+testSet.add(2);
+>testSet.add : Symbol(SetOf.add, Decl(inferFromGenericFunctionReturnTypes2.ts, 26, 14))
+>testSet : Symbol(testSet, Decl(inferFromGenericFunctionReturnTypes2.ts, 70, 5))
+>add : Symbol(SetOf.add, Decl(inferFromGenericFunctionReturnTypes2.ts, 26, 14))
+
+testSet.add(3);
+>testSet.add : Symbol(SetOf.add, Decl(inferFromGenericFunctionReturnTypes2.ts, 26, 14))
+>testSet : Symbol(testSet, Decl(inferFromGenericFunctionReturnTypes2.ts, 70, 5))
+>add : Symbol(SetOf.add, Decl(inferFromGenericFunctionReturnTypes2.ts, 26, 14))
+
+const t1 = testSet.transform(
+>t1 : Symbol(t1, Decl(inferFromGenericFunctionReturnTypes2.ts, 75, 5))
+>testSet.transform : Symbol(SetOf.transform, Decl(inferFromGenericFunctionReturnTypes2.ts, 30, 3))
+>testSet : Symbol(testSet, Decl(inferFromGenericFunctionReturnTypes2.ts, 70, 5))
+>transform : Symbol(SetOf.transform, Decl(inferFromGenericFunctionReturnTypes2.ts, 30, 3))
+
+  compose(
+>compose : Symbol(compose, Decl(inferFromGenericFunctionReturnTypes2.ts, 39, 1), Decl(inferFromGenericFunctionReturnTypes2.ts, 46, 28))
+
+    filter(x => x % 1 === 0),
+>filter : Symbol(filter, Decl(inferFromGenericFunctionReturnTypes2.ts, 58, 1))
+>x : Symbol(x, Decl(inferFromGenericFunctionReturnTypes2.ts, 77, 11))
+>x : Symbol(x, Decl(inferFromGenericFunctionReturnTypes2.ts, 77, 11))
+
+    map(x => x + x),
+>map : Symbol(map, Decl(inferFromGenericFunctionReturnTypes2.ts, 50, 1))
+>x : Symbol(x, Decl(inferFromGenericFunctionReturnTypes2.ts, 78, 8))
+>x : Symbol(x, Decl(inferFromGenericFunctionReturnTypes2.ts, 78, 8))
+>x : Symbol(x, Decl(inferFromGenericFunctionReturnTypes2.ts, 78, 8))
+
+    map(x => x + '!!!'),
+>map : Symbol(map, Decl(inferFromGenericFunctionReturnTypes2.ts, 50, 1))
+>x : Symbol(x, Decl(inferFromGenericFunctionReturnTypes2.ts, 79, 8))
+>x : Symbol(x, Decl(inferFromGenericFunctionReturnTypes2.ts, 79, 8))
+
+    map(x => x.toUpperCase())
+>map : Symbol(map, Decl(inferFromGenericFunctionReturnTypes2.ts, 50, 1))
+>x : Symbol(x, Decl(inferFromGenericFunctionReturnTypes2.ts, 80, 8))
+>x.toUpperCase : Symbol(String.toUpperCase, Decl(lib.d.ts, --, --))
+>x : Symbol(x, Decl(inferFromGenericFunctionReturnTypes2.ts, 80, 8))
+>toUpperCase : Symbol(String.toUpperCase, Decl(lib.d.ts, --, --))
+
+  )
+)
+
+declare function identity<T>(x: T): T;
+>identity : Symbol(identity, Decl(inferFromGenericFunctionReturnTypes2.ts, 82, 1))
+>T : Symbol(T, Decl(inferFromGenericFunctionReturnTypes2.ts, 84, 26))
+>x : Symbol(x, Decl(inferFromGenericFunctionReturnTypes2.ts, 84, 29))
+>T : Symbol(T, Decl(inferFromGenericFunctionReturnTypes2.ts, 84, 26))
+>T : Symbol(T, Decl(inferFromGenericFunctionReturnTypes2.ts, 84, 26))
+
+const t2 = testSet.transform(
+>t2 : Symbol(t2, Decl(inferFromGenericFunctionReturnTypes2.ts, 86, 5))
+>testSet.transform : Symbol(SetOf.transform, Decl(inferFromGenericFunctionReturnTypes2.ts, 30, 3))
+>testSet : Symbol(testSet, Decl(inferFromGenericFunctionReturnTypes2.ts, 70, 5))
+>transform : Symbol(SetOf.transform, Decl(inferFromGenericFunctionReturnTypes2.ts, 30, 3))
+
+  compose(
+>compose : Symbol(compose, Decl(inferFromGenericFunctionReturnTypes2.ts, 39, 1), Decl(inferFromGenericFunctionReturnTypes2.ts, 46, 28))
+
+    filter(x => x % 1 === 0),
+>filter : Symbol(filter, Decl(inferFromGenericFunctionReturnTypes2.ts, 58, 1))
+>x : Symbol(x, Decl(inferFromGenericFunctionReturnTypes2.ts, 88, 11))
+>x : Symbol(x, Decl(inferFromGenericFunctionReturnTypes2.ts, 88, 11))
+
+    identity,
+>identity : Symbol(identity, Decl(inferFromGenericFunctionReturnTypes2.ts, 82, 1))
+
+    map(x => x + '!!!'),
+>map : Symbol(map, Decl(inferFromGenericFunctionReturnTypes2.ts, 50, 1))
+>x : Symbol(x, Decl(inferFromGenericFunctionReturnTypes2.ts, 90, 8))
+>x : Symbol(x, Decl(inferFromGenericFunctionReturnTypes2.ts, 90, 8))
+
+    map(x => x.toUpperCase())
+>map : Symbol(map, Decl(inferFromGenericFunctionReturnTypes2.ts, 50, 1))
+>x : Symbol(x, Decl(inferFromGenericFunctionReturnTypes2.ts, 91, 8))
+>x.toUpperCase : Symbol(String.toUpperCase, Decl(lib.d.ts, --, --))
+>x : Symbol(x, Decl(inferFromGenericFunctionReturnTypes2.ts, 91, 8))
+>toUpperCase : Symbol(String.toUpperCase, Decl(lib.d.ts, --, --))
+
+  )
+)
+
diff --git a/tests/baselines/reference/inferFromGenericFunctionReturnTypes2.types b/tests/baselines/reference/inferFromGenericFunctionReturnTypes2.types
new file mode 100644
index 00000000000..a07c5ea4db8
--- /dev/null
+++ b/tests/baselines/reference/inferFromGenericFunctionReturnTypes2.types
@@ -0,0 +1,600 @@
+=== tests/cases/compiler/inferFromGenericFunctionReturnTypes2.ts ===
+type Mapper<T, U> = (x: T) => U;
+>Mapper : Mapper<T, U>
+>T : T
+>U : U
+>x : T
+>T : T
+>U : U
+
+declare function wrap<T, U>(cb: Mapper<T, U>): Mapper<T, U>;
+>wrap : <T, U>(cb: Mapper<T, U>) => Mapper<T, U>
+>T : T
+>U : U
+>cb : Mapper<T, U>
+>Mapper : Mapper<T, U>
+>T : T
+>U : U
+>Mapper : Mapper<T, U>
+>T : T
+>U : U
+
+declare function arrayize<T, U>(cb: Mapper<T, U>): Mapper<T, U[]>;
+>arrayize : <T, U>(cb: Mapper<T, U>) => Mapper<T, U[]>
+>T : T
+>U : U
+>cb : Mapper<T, U>
+>Mapper : Mapper<T, U>
+>T : T
+>U : U
+>Mapper : Mapper<T, U>
+>T : T
+>U : U
+
+declare function combine<A, B, C>(f: (x: A) => B, g: (x: B) => C): (x: A) => C;
+>combine : <A, B, C>(f: (x: A) => B, g: (x: B) => C) => (x: A) => C
+>A : A
+>B : B
+>C : C
+>f : (x: A) => B
+>x : A
+>A : A
+>B : B
+>g : (x: B) => C
+>x : B
+>B : B
+>C : C
+>x : A
+>A : A
+>C : C
+
+declare function foo(f: Mapper<string, number>): void;
+>foo : (f: Mapper<string, number>) => void
+>f : Mapper<string, number>
+>Mapper : Mapper<T, U>
+
+let f1: Mapper<string, number> = s => s.length;
+>f1 : Mapper<string, number>
+>Mapper : Mapper<T, U>
+>s => s.length : (s: string) => number
+>s : string
+>s.length : number
+>s : string
+>length : number
+
+let f2: Mapper<string, number> = wrap(s => s.length);
+>f2 : Mapper<string, number>
+>Mapper : Mapper<T, U>
+>wrap(s => s.length) : Mapper<string, number>
+>wrap : <T, U>(cb: Mapper<T, U>) => Mapper<T, U>
+>s => s.length : (s: string) => number
+>s : string
+>s.length : number
+>s : string
+>length : number
+
+let f3: Mapper<string, number[]> = arrayize(wrap(s => s.length));
+>f3 : Mapper<string, number[]>
+>Mapper : Mapper<T, U>
+>arrayize(wrap(s => s.length)) : Mapper<string, number[]>
+>arrayize : <T, U>(cb: Mapper<T, U>) => Mapper<T, U[]>
+>wrap(s => s.length) : Mapper<string, number>
+>wrap : <T, U>(cb: Mapper<T, U>) => Mapper<T, U>
+>s => s.length : (s: string) => number
+>s : string
+>s.length : number
+>s : string
+>length : number
+
+let f4: Mapper<string, boolean> = combine(wrap(s => s.length), wrap(n => n >= 10));
+>f4 : Mapper<string, boolean>
+>Mapper : Mapper<T, U>
+>combine(wrap(s => s.length), wrap(n => n >= 10)) : (x: string) => boolean
+>combine : <A, B, C>(f: (x: A) => B, g: (x: B) => C) => (x: A) => C
+>wrap(s => s.length) : Mapper<string, number>
+>wrap : <T, U>(cb: Mapper<T, U>) => Mapper<T, U>
+>s => s.length : (s: string) => number
+>s : string
+>s.length : number
+>s : string
+>length : number
+>wrap(n => n >= 10) : Mapper<number, boolean>
+>wrap : <T, U>(cb: Mapper<T, U>) => Mapper<T, U>
+>n => n >= 10 : (n: number) => boolean
+>n : number
+>n >= 10 : boolean
+>n : number
+>10 : 10
+
+foo(wrap(s => s.length));
+>foo(wrap(s => s.length)) : void
+>foo : (f: Mapper<string, number>) => void
+>wrap(s => s.length) : Mapper<string, number>
+>wrap : <T, U>(cb: Mapper<T, U>) => Mapper<T, U>
+>s => s.length : (s: string) => number
+>s : string
+>s.length : number
+>s : string
+>length : number
+
+let a1 = ["a", "b"].map(s => s.length);
+>a1 : number[]
+>["a", "b"].map(s => s.length) : number[]
+>["a", "b"].map : { <U>(this: [string, string, string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U): [U, U, U, U, U]; <U>(this: [string, string, string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): [U, U, U, U, U]; <Z, U>(this: [string, string, string, string, string], callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): [U, U, U, U, U]; <U>(this: [string, string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U): [U, U, U, U]; <U>(this: [string, string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): [U, U, U, U]; <Z, U>(this: [string, string, string, string], callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): [U, U, U, U]; <U>(this: [string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U): [U, U, U]; <U>(this: [string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): [U, U, U]; <Z, U>(this: [string, string, string], callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): [U, U, U]; <U>(this: [string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U): [U, U]; <U>(this: [string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): [U, U]; <Z, U>(this: [string, string], callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): [U, U]; <U>(callbackfn: (this: void, value: string, index: number, array: string[]) => U): U[]; <U>(callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): U[]; <Z, U>(callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): U[]; }
+>["a", "b"] : string[]
+>"a" : "a"
+>"b" : "b"
+>map : { <U>(this: [string, string, string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U): [U, U, U, U, U]; <U>(this: [string, string, string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): [U, U, U, U, U]; <Z, U>(this: [string, string, string, string, string], callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): [U, U, U, U, U]; <U>(this: [string, string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U): [U, U, U, U]; <U>(this: [string, string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): [U, U, U, U]; <Z, U>(this: [string, string, string, string], callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): [U, U, U, U]; <U>(this: [string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U): [U, U, U]; <U>(this: [string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): [U, U, U]; <Z, U>(this: [string, string, string], callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): [U, U, U]; <U>(this: [string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U): [U, U]; <U>(this: [string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): [U, U]; <Z, U>(this: [string, string], callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): [U, U]; <U>(callbackfn: (this: void, value: string, index: number, array: string[]) => U): U[]; <U>(callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): U[]; <Z, U>(callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): U[]; }
+>s => s.length : (this: void, s: string) => number
+>s : string
+>s.length : number
+>s : string
+>length : number
+
+let a2 = ["a", "b"].map(wrap(s => s.length));
+>a2 : number[]
+>["a", "b"].map(wrap(s => s.length)) : number[]
+>["a", "b"].map : { <U>(this: [string, string, string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U): [U, U, U, U, U]; <U>(this: [string, string, string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): [U, U, U, U, U]; <Z, U>(this: [string, string, string, string, string], callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): [U, U, U, U, U]; <U>(this: [string, string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U): [U, U, U, U]; <U>(this: [string, string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): [U, U, U, U]; <Z, U>(this: [string, string, string, string], callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): [U, U, U, U]; <U>(this: [string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U): [U, U, U]; <U>(this: [string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): [U, U, U]; <Z, U>(this: [string, string, string], callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): [U, U, U]; <U>(this: [string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U): [U, U]; <U>(this: [string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): [U, U]; <Z, U>(this: [string, string], callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): [U, U]; <U>(callbackfn: (this: void, value: string, index: number, array: string[]) => U): U[]; <U>(callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): U[]; <Z, U>(callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): U[]; }
+>["a", "b"] : string[]
+>"a" : "a"
+>"b" : "b"
+>map : { <U>(this: [string, string, string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U): [U, U, U, U, U]; <U>(this: [string, string, string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): [U, U, U, U, U]; <Z, U>(this: [string, string, string, string, string], callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): [U, U, U, U, U]; <U>(this: [string, string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U): [U, U, U, U]; <U>(this: [string, string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): [U, U, U, U]; <Z, U>(this: [string, string, string, string], callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): [U, U, U, U]; <U>(this: [string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U): [U, U, U]; <U>(this: [string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): [U, U, U]; <Z, U>(this: [string, string, string], callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): [U, U, U]; <U>(this: [string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U): [U, U]; <U>(this: [string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): [U, U]; <Z, U>(this: [string, string], callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): [U, U]; <U>(callbackfn: (this: void, value: string, index: number, array: string[]) => U): U[]; <U>(callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): U[]; <Z, U>(callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): U[]; }
+>wrap(s => s.length) : Mapper<string, number>
+>wrap : <T, U>(cb: Mapper<T, U>) => Mapper<T, U>
+>s => s.length : (s: string) => number
+>s : string
+>s.length : number
+>s : string
+>length : number
+
+let a3 = ["a", "b"].map(wrap(arrayize(s => s.length)));
+>a3 : number[][]
+>["a", "b"].map(wrap(arrayize(s => s.length))) : number[][]
+>["a", "b"].map : { <U>(this: [string, string, string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U): [U, U, U, U, U]; <U>(this: [string, string, string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): [U, U, U, U, U]; <Z, U>(this: [string, string, string, string, string], callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): [U, U, U, U, U]; <U>(this: [string, string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U): [U, U, U, U]; <U>(this: [string, string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): [U, U, U, U]; <Z, U>(this: [string, string, string, string], callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): [U, U, U, U]; <U>(this: [string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U): [U, U, U]; <U>(this: [string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): [U, U, U]; <Z, U>(this: [string, string, string], callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): [U, U, U]; <U>(this: [string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U): [U, U]; <U>(this: [string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): [U, U]; <Z, U>(this: [string, string], callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): [U, U]; <U>(callbackfn: (this: void, value: string, index: number, array: string[]) => U): U[]; <U>(callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): U[]; <Z, U>(callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): U[]; }
+>["a", "b"] : string[]
+>"a" : "a"
+>"b" : "b"
+>map : { <U>(this: [string, string, string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U): [U, U, U, U, U]; <U>(this: [string, string, string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): [U, U, U, U, U]; <Z, U>(this: [string, string, string, string, string], callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): [U, U, U, U, U]; <U>(this: [string, string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U): [U, U, U, U]; <U>(this: [string, string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): [U, U, U, U]; <Z, U>(this: [string, string, string, string], callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): [U, U, U, U]; <U>(this: [string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U): [U, U, U]; <U>(this: [string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): [U, U, U]; <Z, U>(this: [string, string, string], callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): [U, U, U]; <U>(this: [string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U): [U, U]; <U>(this: [string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): [U, U]; <Z, U>(this: [string, string], callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): [U, U]; <U>(callbackfn: (this: void, value: string, index: number, array: string[]) => U): U[]; <U>(callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): U[]; <Z, U>(callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): U[]; }
+>wrap(arrayize(s => s.length)) : Mapper<string, number[]>
+>wrap : <T, U>(cb: Mapper<T, U>) => Mapper<T, U>
+>arrayize(s => s.length) : Mapper<string, number[]>
+>arrayize : <T, U>(cb: Mapper<T, U>) => Mapper<T, U[]>
+>s => s.length : (s: string) => number
+>s : string
+>s.length : number
+>s : string
+>length : number
+
+let a4 = ["a", "b"].map(combine(wrap(s => s.length), wrap(n => n > 10)));
+>a4 : boolean[]
+>["a", "b"].map(combine(wrap(s => s.length), wrap(n => n > 10))) : boolean[]
+>["a", "b"].map : { <U>(this: [string, string, string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U): [U, U, U, U, U]; <U>(this: [string, string, string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): [U, U, U, U, U]; <Z, U>(this: [string, string, string, string, string], callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): [U, U, U, U, U]; <U>(this: [string, string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U): [U, U, U, U]; <U>(this: [string, string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): [U, U, U, U]; <Z, U>(this: [string, string, string, string], callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): [U, U, U, U]; <U>(this: [string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U): [U, U, U]; <U>(this: [string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): [U, U, U]; <Z, U>(this: [string, string, string], callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): [U, U, U]; <U>(this: [string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U): [U, U]; <U>(this: [string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): [U, U]; <Z, U>(this: [string, string], callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): [U, U]; <U>(callbackfn: (this: void, value: string, index: number, array: string[]) => U): U[]; <U>(callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): U[]; <Z, U>(callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): U[]; }
+>["a", "b"] : string[]
+>"a" : "a"
+>"b" : "b"
+>map : { <U>(this: [string, string, string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U): [U, U, U, U, U]; <U>(this: [string, string, string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): [U, U, U, U, U]; <Z, U>(this: [string, string, string, string, string], callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): [U, U, U, U, U]; <U>(this: [string, string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U): [U, U, U, U]; <U>(this: [string, string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): [U, U, U, U]; <Z, U>(this: [string, string, string, string], callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): [U, U, U, U]; <U>(this: [string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U): [U, U, U]; <U>(this: [string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): [U, U, U]; <Z, U>(this: [string, string, string], callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): [U, U, U]; <U>(this: [string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U): [U, U]; <U>(this: [string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): [U, U]; <Z, U>(this: [string, string], callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): [U, U]; <U>(callbackfn: (this: void, value: string, index: number, array: string[]) => U): U[]; <U>(callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): U[]; <Z, U>(callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): U[]; }
+>combine(wrap(s => s.length), wrap(n => n > 10)) : (x: string) => boolean
+>combine : <A, B, C>(f: (x: A) => B, g: (x: B) => C) => (x: A) => C
+>wrap(s => s.length) : Mapper<string, number>
+>wrap : <T, U>(cb: Mapper<T, U>) => Mapper<T, U>
+>s => s.length : (s: string) => number
+>s : string
+>s.length : number
+>s : string
+>length : number
+>wrap(n => n > 10) : Mapper<number, boolean>
+>wrap : <T, U>(cb: Mapper<T, U>) => Mapper<T, U>
+>n => n > 10 : (n: number) => boolean
+>n : number
+>n > 10 : boolean
+>n : number
+>10 : 10
+
+let a5 = ["a", "b"].map(combine(identity, wrap(s => s.length)));
+>a5 : number[]
+>["a", "b"].map(combine(identity, wrap(s => s.length))) : number[]
+>["a", "b"].map : { <U>(this: [string, string, string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U): [U, U, U, U, U]; <U>(this: [string, string, string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): [U, U, U, U, U]; <Z, U>(this: [string, string, string, string, string], callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): [U, U, U, U, U]; <U>(this: [string, string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U): [U, U, U, U]; <U>(this: [string, string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): [U, U, U, U]; <Z, U>(this: [string, string, string, string], callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): [U, U, U, U]; <U>(this: [string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U): [U, U, U]; <U>(this: [string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): [U, U, U]; <Z, U>(this: [string, string, string], callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): [U, U, U]; <U>(this: [string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U): [U, U]; <U>(this: [string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): [U, U]; <Z, U>(this: [string, string], callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): [U, U]; <U>(callbackfn: (this: void, value: string, index: number, array: string[]) => U): U[]; <U>(callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): U[]; <Z, U>(callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): U[]; }
+>["a", "b"] : string[]
+>"a" : "a"
+>"b" : "b"
+>map : { <U>(this: [string, string, string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U): [U, U, U, U, U]; <U>(this: [string, string, string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): [U, U, U, U, U]; <Z, U>(this: [string, string, string, string, string], callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): [U, U, U, U, U]; <U>(this: [string, string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U): [U, U, U, U]; <U>(this: [string, string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): [U, U, U, U]; <Z, U>(this: [string, string, string, string], callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): [U, U, U, U]; <U>(this: [string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U): [U, U, U]; <U>(this: [string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): [U, U, U]; <Z, U>(this: [string, string, string], callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): [U, U, U]; <U>(this: [string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U): [U, U]; <U>(this: [string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): [U, U]; <Z, U>(this: [string, string], callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): [U, U]; <U>(callbackfn: (this: void, value: string, index: number, array: string[]) => U): U[]; <U>(callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): U[]; <Z, U>(callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): U[]; }
+>combine(identity, wrap(s => s.length)) : (x: string) => number
+>combine : <A, B, C>(f: (x: A) => B, g: (x: B) => C) => (x: A) => C
+>identity : <T>(x: T) => T
+>wrap(s => s.length) : Mapper<string, number>
+>wrap : <T, U>(cb: Mapper<T, U>) => Mapper<T, U>
+>s => s.length : (s: string) => number
+>s : string
+>s.length : number
+>s : string
+>length : number
+
+let a6 = ["a", "b"].map(combine(wrap(s => s.length), identity));
+>a6 : number[]
+>["a", "b"].map(combine(wrap(s => s.length), identity)) : number[]
+>["a", "b"].map : { <U>(this: [string, string, string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U): [U, U, U, U, U]; <U>(this: [string, string, string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): [U, U, U, U, U]; <Z, U>(this: [string, string, string, string, string], callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): [U, U, U, U, U]; <U>(this: [string, string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U): [U, U, U, U]; <U>(this: [string, string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): [U, U, U, U]; <Z, U>(this: [string, string, string, string], callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): [U, U, U, U]; <U>(this: [string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U): [U, U, U]; <U>(this: [string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): [U, U, U]; <Z, U>(this: [string, string, string], callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): [U, U, U]; <U>(this: [string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U): [U, U]; <U>(this: [string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): [U, U]; <Z, U>(this: [string, string], callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): [U, U]; <U>(callbackfn: (this: void, value: string, index: number, array: string[]) => U): U[]; <U>(callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): U[]; <Z, U>(callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): U[]; }
+>["a", "b"] : string[]
+>"a" : "a"
+>"b" : "b"
+>map : { <U>(this: [string, string, string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U): [U, U, U, U, U]; <U>(this: [string, string, string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): [U, U, U, U, U]; <Z, U>(this: [string, string, string, string, string], callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): [U, U, U, U, U]; <U>(this: [string, string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U): [U, U, U, U]; <U>(this: [string, string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): [U, U, U, U]; <Z, U>(this: [string, string, string, string], callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): [U, U, U, U]; <U>(this: [string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U): [U, U, U]; <U>(this: [string, string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): [U, U, U]; <Z, U>(this: [string, string, string], callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): [U, U, U]; <U>(this: [string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U): [U, U]; <U>(this: [string, string], callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): [U, U]; <Z, U>(this: [string, string], callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): [U, U]; <U>(callbackfn: (this: void, value: string, index: number, array: string[]) => U): U[]; <U>(callbackfn: (this: void, value: string, index: number, array: string[]) => U, thisArg: undefined): U[]; <Z, U>(callbackfn: (this: Z, value: string, index: number, array: string[]) => U, thisArg: Z): U[]; }
+>combine(wrap(s => s.length), identity) : (x: string) => number
+>combine : <A, B, C>(f: (x: A) => B, g: (x: B) => C) => (x: A) => C
+>wrap(s => s.length) : Mapper<string, number>
+>wrap : <T, U>(cb: Mapper<T, U>) => Mapper<T, U>
+>s => s.length : (s: string) => number
+>s : string
+>s.length : number
+>s : string
+>length : number
+>identity : <T>(x: T) => T
+
+// This is a contrived class. We could do the same thing with Observables, etc.
+class SetOf<A> {
+>SetOf : SetOf<A>
+>A : A
+
+  _store: A[];
+>_store : A[]
+>A : A
+
+  add(a: A) {
+>add : (a: A) => void
+>a : A
+>A : A
+
+    this._store.push(a);
+>this._store.push(a) : number
+>this._store.push : (...items: A[]) => number
+>this._store : A[]
+>this : this
+>_store : A[]
+>push : (...items: A[]) => number
+>a : A
+  }
+
+  transform<B>(transformer: (a: SetOf<A>) => SetOf<B>): SetOf<B> {
+>transform : <B>(transformer: (a: SetOf<A>) => SetOf<B>) => SetOf<B>
+>B : B
+>transformer : (a: SetOf<A>) => SetOf<B>
+>a : SetOf<A>
+>SetOf : SetOf<A>
+>A : A
+>SetOf : SetOf<A>
+>B : B
+>SetOf : SetOf<A>
+>B : B
+
+    return transformer(this);
+>transformer(this) : SetOf<B>
+>transformer : (a: SetOf<A>) => SetOf<B>
+>this : this
+  }
+
+  forEach(fn: (a: A, index: number) => void) {
+>forEach : (fn: (a: A, index: number) => void) => void
+>fn : (a: A, index: number) => void
+>a : A
+>A : A
+>index : number
+
+      this._store.forEach((a, i) => fn(a, i));
+>this._store.forEach((a, i) => fn(a, i)) : void
+>this._store.forEach : { (callbackfn: (this: void, value: A, index: number, array: A[]) => void): void; (callbackfn: (this: void, value: A, index: number, array: A[]) => void, thisArg: undefined): void; <Z>(callbackfn: (this: Z, value: A, index: number, array: A[]) => void, thisArg: Z): void; }
+>this._store : A[]
+>this : this
+>_store : A[]
+>forEach : { (callbackfn: (this: void, value: A, index: number, array: A[]) => void): void; (callbackfn: (this: void, value: A, index: number, array: A[]) => void, thisArg: undefined): void; <Z>(callbackfn: (this: Z, value: A, index: number, array: A[]) => void, thisArg: Z): void; }
+>(a, i) => fn(a, i) : (this: void, a: A, i: number) => void
+>a : A
+>i : number
+>fn(a, i) : void
+>fn : (a: A, index: number) => void
+>a : A
+>i : number
+  }
+}
+
+function compose<A, B, C, D, E>(
+>compose : <A, B, C, D, E>(fnA: (a: SetOf<A>) => SetOf<B>, fnB: (b: SetOf<B>) => SetOf<C>, fnC: (c: SetOf<C>) => SetOf<D>, fnD: (c: SetOf<D>) => SetOf<E>) => (x: SetOf<A>) => SetOf<E>
+>A : A
+>B : B
+>C : C
+>D : D
+>E : E
+
+  fnA: (a: SetOf<A>) => SetOf<B>, 
+>fnA : (a: SetOf<A>) => SetOf<B>
+>a : SetOf<A>
+>SetOf : SetOf<A>
+>A : A
+>SetOf : SetOf<A>
+>B : B
+
+  fnB: (b: SetOf<B>) => SetOf<C>, 
+>fnB : (b: SetOf<B>) => SetOf<C>
+>b : SetOf<B>
+>SetOf : SetOf<A>
+>B : B
+>SetOf : SetOf<A>
+>C : C
+
+  fnC: (c: SetOf<C>) => SetOf<D>,
+>fnC : (c: SetOf<C>) => SetOf<D>
+>c : SetOf<C>
+>SetOf : SetOf<A>
+>C : C
+>SetOf : SetOf<A>
+>D : D
+
+  fnD: (c: SetOf<D>) => SetOf<E>,
+>fnD : (c: SetOf<D>) => SetOf<E>
+>c : SetOf<D>
+>SetOf : SetOf<A>
+>D : D
+>SetOf : SetOf<A>
+>E : E
+
+):(x: SetOf<A>) => SetOf<E>;
+>x : SetOf<A>
+>SetOf : SetOf<A>
+>A : A
+>SetOf : SetOf<A>
+>E : E
+
+/* ... etc ... */
+function compose<T>(...fns: ((x: T) => T)[]): (x: T) => T {
+>compose : <A, B, C, D, E>(fnA: (a: SetOf<A>) => SetOf<B>, fnB: (b: SetOf<B>) => SetOf<C>, fnC: (c: SetOf<C>) => SetOf<D>, fnD: (c: SetOf<D>) => SetOf<E>) => (x: SetOf<A>) => SetOf<E>
+>T : T
+>fns : ((x: T) => T)[]
+>x : T
+>T : T
+>T : T
+>x : T
+>T : T
+>T : T
+
+  return (x: T) => fns.reduce((prev, fn) => fn(prev), x);
+>(x: T) => fns.reduce((prev, fn) => fn(prev), x) : (x: T) => T
+>x : T
+>T : T
+>fns.reduce((prev, fn) => fn(prev), x) : T
+>fns.reduce : { (callbackfn: (previousValue: (x: T) => T, currentValue: (x: T) => T, currentIndex: number, array: ((x: T) => T)[]) => (x: T) => T, initialValue?: (x: T) => T): (x: T) => T; <U>(callbackfn: (previousValue: U, currentValue: (x: T) => T, currentIndex: number, array: ((x: T) => T)[]) => U, initialValue: U): U; }
+>fns : ((x: T) => T)[]
+>reduce : { (callbackfn: (previousValue: (x: T) => T, currentValue: (x: T) => T, currentIndex: number, array: ((x: T) => T)[]) => (x: T) => T, initialValue?: (x: T) => T): (x: T) => T; <U>(callbackfn: (previousValue: U, currentValue: (x: T) => T, currentIndex: number, array: ((x: T) => T)[]) => U, initialValue: U): U; }
+>(prev, fn) => fn(prev) : (prev: T, fn: (x: T) => T) => T
+>prev : T
+>fn : (x: T) => T
+>fn(prev) : T
+>fn : (x: T) => T
+>prev : T
+>x : T
+}
+
+function map<A, B>(fn: (a: A) => B): (s: SetOf<A>) => SetOf<B> {
+>map : <A, B>(fn: (a: A) => B) => (s: SetOf<A>) => SetOf<B>
+>A : A
+>B : B
+>fn : (a: A) => B
+>a : A
+>A : A
+>B : B
+>s : SetOf<A>
+>SetOf : SetOf<A>
+>A : A
+>SetOf : SetOf<A>
+>B : B
+
+  return (a: SetOf<A>) => {
+>(a: SetOf<A>) => {    const b: SetOf<B> = new SetOf();    a.forEach(x => b.add(fn(x)));    return b;  } : (a: SetOf<A>) => SetOf<B>
+>a : SetOf<A>
+>SetOf : SetOf<A>
+>A : A
+
+    const b: SetOf<B> = new SetOf();
+>b : SetOf<B>
+>SetOf : SetOf<A>
+>B : B
+>new SetOf() : SetOf<B>
+>SetOf : typeof SetOf
+
+    a.forEach(x => b.add(fn(x)));
+>a.forEach(x => b.add(fn(x))) : void
+>a.forEach : (fn: (a: A, index: number) => void) => void
+>a : SetOf<A>
+>forEach : (fn: (a: A, index: number) => void) => void
+>x => b.add(fn(x)) : (x: A) => void
+>x : A
+>b.add(fn(x)) : void
+>b.add : (a: B) => void
+>b : SetOf<B>
+>add : (a: B) => void
+>fn(x) : B
+>fn : (a: A) => B
+>x : A
+
+    return b;
+>b : SetOf<B>
+  }
+}
+
+function filter<A>(predicate: (a: A) => boolean): (s: SetOf<A>) => SetOf<A> {
+>filter : <A>(predicate: (a: A) => boolean) => (s: SetOf<A>) => SetOf<A>
+>A : A
+>predicate : (a: A) => boolean
+>a : A
+>A : A
+>s : SetOf<A>
+>SetOf : SetOf<A>
+>A : A
+>SetOf : SetOf<A>
+>A : A
+
+  return (a: SetOf<A>) => {
+>(a: SetOf<A>) => {    const result = new SetOf<A>();    a.forEach(x => {      if (predicate(x)) result.add(x);    });   return result;  } : (a: SetOf<A>) => SetOf<A>
+>a : SetOf<A>
+>SetOf : SetOf<A>
+>A : A
+
+    const result = new SetOf<A>();
+>result : SetOf<A>
+>new SetOf<A>() : SetOf<A>
+>SetOf : typeof SetOf
+>A : A
+
+    a.forEach(x => {
+>a.forEach(x => {      if (predicate(x)) result.add(x);    }) : void
+>a.forEach : (fn: (a: A, index: number) => void) => void
+>a : SetOf<A>
+>forEach : (fn: (a: A, index: number) => void) => void
+>x => {      if (predicate(x)) result.add(x);    } : (x: A) => void
+>x : A
+
+      if (predicate(x)) result.add(x);
+>predicate(x) : boolean
+>predicate : (a: A) => boolean
+>x : A
+>result.add(x) : void
+>result.add : (a: A) => void
+>result : SetOf<A>
+>add : (a: A) => void
+>x : A
+
+    });
+   return result;
+>result : SetOf<A>
+  }
+}
+
+const testSet = new SetOf<number>();
+>testSet : SetOf<number>
+>new SetOf<number>() : SetOf<number>
+>SetOf : typeof SetOf
+
+testSet.add(1);
+>testSet.add(1) : void
+>testSet.add : (a: number) => void
+>testSet : SetOf<number>
+>add : (a: number) => void
+>1 : 1
+
+testSet.add(2);
+>testSet.add(2) : void
+>testSet.add : (a: number) => void
+>testSet : SetOf<number>
+>add : (a: number) => void
+>2 : 2
+
+testSet.add(3);
+>testSet.add(3) : void
+>testSet.add : (a: number) => void
+>testSet : SetOf<number>
+>add : (a: number) => void
+>3 : 3
+
+const t1 = testSet.transform(
+>t1 : SetOf<string>
+>testSet.transform(  compose(    filter(x => x % 1 === 0),    map(x => x + x),    map(x => x + '!!!'),    map(x => x.toUpperCase())  )) : SetOf<string>
+>testSet.transform : <B>(transformer: (a: SetOf<number>) => SetOf<B>) => SetOf<B>
+>testSet : SetOf<number>
+>transform : <B>(transformer: (a: SetOf<number>) => SetOf<B>) => SetOf<B>
+
+  compose(
+>compose(    filter(x => x % 1 === 0),    map(x => x + x),    map(x => x + '!!!'),    map(x => x.toUpperCase())  ) : (x: SetOf<number>) => SetOf<string>
+>compose : <A, B, C, D, E>(fnA: (a: SetOf<A>) => SetOf<B>, fnB: (b: SetOf<B>) => SetOf<C>, fnC: (c: SetOf<C>) => SetOf<D>, fnD: (c: SetOf<D>) => SetOf<E>) => (x: SetOf<A>) => SetOf<E>
+
+    filter(x => x % 1 === 0),
+>filter(x => x % 1 === 0) : (s: SetOf<number>) => SetOf<number>
+>filter : <A>(predicate: (a: A) => boolean) => (s: SetOf<A>) => SetOf<A>
+>x => x % 1 === 0 : (x: number) => boolean
+>x : number
+>x % 1 === 0 : boolean
+>x % 1 : number
+>x : number
+>1 : 1
+>0 : 0
+
+    map(x => x + x),
+>map(x => x + x) : (s: SetOf<number>) => SetOf<number>
+>map : <A, B>(fn: (a: A) => B) => (s: SetOf<A>) => SetOf<B>
+>x => x + x : (x: number) => number
+>x : number
+>x + x : number
+>x : number
+>x : number
+
+    map(x => x + '!!!'),
+>map(x => x + '!!!') : (s: SetOf<number>) => SetOf<string>
+>map : <A, B>(fn: (a: A) => B) => (s: SetOf<A>) => SetOf<B>
+>x => x + '!!!' : (x: number) => string
+>x : number
+>x + '!!!' : string
+>x : number
+>'!!!' : "!!!"
+
+    map(x => x.toUpperCase())
+>map(x => x.toUpperCase()) : (s: SetOf<string>) => SetOf<string>
+>map : <A, B>(fn: (a: A) => B) => (s: SetOf<A>) => SetOf<B>
+>x => x.toUpperCase() : (x: string) => string
+>x : string
+>x.toUpperCase() : string
+>x.toUpperCase : () => string
+>x : string
+>toUpperCase : () => string
+
+  )
+)
+
+declare function identity<T>(x: T): T;
+>identity : <T>(x: T) => T
+>T : T
+>x : T
+>T : T
+>T : T
+
+const t2 = testSet.transform(
+>t2 : SetOf<string>
+>testSet.transform(  compose(    filter(x => x % 1 === 0),    identity,    map(x => x + '!!!'),    map(x => x.toUpperCase())  )) : SetOf<string>
+>testSet.transform : <B>(transformer: (a: SetOf<number>) => SetOf<B>) => SetOf<B>
+>testSet : SetOf<number>
+>transform : <B>(transformer: (a: SetOf<number>) => SetOf<B>) => SetOf<B>
+
+  compose(
+>compose(    filter(x => x % 1 === 0),    identity,    map(x => x + '!!!'),    map(x => x.toUpperCase())  ) : (x: SetOf<number>) => SetOf<string>
+>compose : <A, B, C, D, E>(fnA: (a: SetOf<A>) => SetOf<B>, fnB: (b: SetOf<B>) => SetOf<C>, fnC: (c: SetOf<C>) => SetOf<D>, fnD: (c: SetOf<D>) => SetOf<E>) => (x: SetOf<A>) => SetOf<E>
+
+    filter(x => x % 1 === 0),
+>filter(x => x % 1 === 0) : (s: SetOf<number>) => SetOf<number>
+>filter : <A>(predicate: (a: A) => boolean) => (s: SetOf<A>) => SetOf<A>
+>x => x % 1 === 0 : (x: number) => boolean
+>x : number
+>x % 1 === 0 : boolean
+>x % 1 : number
+>x : number
+>1 : 1
+>0 : 0
+
+    identity,
+>identity : <T>(x: T) => T
+
+    map(x => x + '!!!'),
+>map(x => x + '!!!') : (s: SetOf<number>) => SetOf<string>
+>map : <A, B>(fn: (a: A) => B) => (s: SetOf<A>) => SetOf<B>
+>x => x + '!!!' : (x: number) => string
+>x : number
+>x + '!!!' : string
+>x : number
+>'!!!' : "!!!"
+
+    map(x => x.toUpperCase())
+>map(x => x.toUpperCase()) : (s: SetOf<string>) => SetOf<string>
+>map : <A, B>(fn: (a: A) => B) => (s: SetOf<A>) => SetOf<B>
+>x => x.toUpperCase() : (x: string) => string
+>x : string
+>x.toUpperCase() : string
+>x.toUpperCase : () => string
+>x : string
+>toUpperCase : () => string
+
+  )
+)
+

From 348fc7e51e1df2136b815c7d2847ede78983bccc Mon Sep 17 00:00:00 2001
From: Kanchalai Tanglertsampan <yuisu@microsoft.com>
Date: Wed, 24 May 2017 16:37:02 -0700
Subject: [PATCH 28/56] Take into account optional property in parameter

---
 src/compiler/binder.ts | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/compiler/binder.ts b/src/compiler/binder.ts
index 204a979d928..8870757999f 100644
--- a/src/compiler/binder.ts
+++ b/src/compiler/binder.ts
@@ -1,4 +1,4 @@
-/// <reference path="utilities.ts"/>
+/// <reference path="utilities.ts"/>
 /// <reference path="parser.ts"/>
 
 /* @internal */
@@ -2178,7 +2178,11 @@ namespace ts {
                 case SyntaxKind.JSDocRecordMember:
                     return bindPropertyWorker(node as JSDocRecordMember);
                 case SyntaxKind.JSDocPropertyTag:
-                    return declareSymbolAndAddToSymbolTable(node as JSDocPropertyTag, SymbolFlags.Property, SymbolFlags.PropertyExcludes);
+                    let optionalType = 0;
+                    if ((node as JSDocPropertyTag).typeExpression.type.kind === SyntaxKind.JSDocOptionalType) {
+                        optionalType = SymbolFlags.Optional;
+                    }
+                    return declareSymbolAndAddToSymbolTable(node as JSDocPropertyTag, SymbolFlags.Property | optionalType, SymbolFlags.PropertyExcludes);
                 case SyntaxKind.JSDocFunctionType:
                     return bindFunctionOrConstructorType(<SignatureDeclaration>node);
                 case SyntaxKind.JSDocTypeLiteral:

From 0d1e41d9379f32d33b8751d079cb7255ef302e78 Mon Sep 17 00:00:00 2001
From: Andy Hanson <anhans@microsoft.com>
Date: Thu, 25 May 2017 08:40:27 -0700
Subject: [PATCH 29/56] In findAllReferences, always return undefined (global)
 symbol scope for properties; also update baselines

---
 src/services/findAllReferences.ts             |  9 +++------
 .../isomorphicMappedTypeInference.symbols     |  4 ++--
 .../reference/keyofAndIndexedAccess.symbols   | 16 +++++++--------
 .../reference/mappedTypeModifiers.symbols     | 16 +++++++--------
 .../baselines/reference/mappedTypes2.symbols  | 20 +++++++++----------
 .../baselines/reference/mappedTypes3.symbols  |  8 ++++----
 .../reference/typeVariableTypeGuards.symbols  |  8 ++++----
 7 files changed, 39 insertions(+), 42 deletions(-)

diff --git a/src/services/findAllReferences.ts b/src/services/findAllReferences.ts
index efc6a6f6ed1..e12215abde0 100644
--- a/src/services/findAllReferences.ts
+++ b/src/services/findAllReferences.ts
@@ -650,10 +650,12 @@ namespace ts.FindAllReferences.Core {
 
         // If this is private property or method, the scope is the containing class
         if (flags & (SymbolFlags.Property | SymbolFlags.Method)) {
-            const privateDeclaration = find(declarations, d => !!(getModifierFlags(d) & ModifierFlags.Private));
+            const privateDeclaration = find(declarations, d => hasModifier(d, ModifierFlags.Private));
             if (privateDeclaration) {
                 return getAncestor(privateDeclaration, SyntaxKind.ClassDeclaration);
             }
+            // Else this is a public property and could be accessed from anywhere.
+            return undefined;
         }
 
         // If symbol is of object binding pattern element without property name we would want to
@@ -669,11 +671,6 @@ namespace ts.FindAllReferences.Core {
             return undefined;
         }
 
-        // If this is a synthetic property, it's a property and must be searched for globally.
-        if ((flags & SymbolFlags.Transient && (<TransientSymbol>symbol).checkFlags & CheckFlags.Synthetic)) {
-            return undefined;
-        }
-
         let scope: Node | undefined;
         for (const declaration of declarations) {
             const container = getContainerNode(declaration);
diff --git a/tests/baselines/reference/isomorphicMappedTypeInference.symbols b/tests/baselines/reference/isomorphicMappedTypeInference.symbols
index 6c638f442c8..48765d15260 100644
--- a/tests/baselines/reference/isomorphicMappedTypeInference.symbols
+++ b/tests/baselines/reference/isomorphicMappedTypeInference.symbols
@@ -149,9 +149,9 @@ function f1() {
     let x: number = b.a.value;
 >x : Symbol(x, Decl(isomorphicMappedTypeInference.ts, 45, 7))
 >b.a.value : Symbol(value, Decl(isomorphicMappedTypeInference.ts, 0, 15))
->b.a : Symbol(a)
+>b.a : Symbol(a, Decl(isomorphicMappedTypeInference.ts, 39, 13))
 >b : Symbol(b, Decl(isomorphicMappedTypeInference.ts, 44, 7))
->a : Symbol(a)
+>a : Symbol(a, Decl(isomorphicMappedTypeInference.ts, 39, 13))
 >value : Symbol(value, Decl(isomorphicMappedTypeInference.ts, 0, 15))
 }
 
diff --git a/tests/baselines/reference/keyofAndIndexedAccess.symbols b/tests/baselines/reference/keyofAndIndexedAccess.symbols
index 6d7e886d26c..65cc44fe84b 100644
--- a/tests/baselines/reference/keyofAndIndexedAccess.symbols
+++ b/tests/baselines/reference/keyofAndIndexedAccess.symbols
@@ -820,19 +820,19 @@ function f71(func: <T, U>(x: T, y: U) => Partial<T & U>) {
 >c : Symbol(c, Decl(keyofAndIndexedAccess.ts, 226, 40))
 
     x.a;  // number | undefined
->x.a : Symbol(a)
+>x.a : Symbol(a, Decl(keyofAndIndexedAccess.ts, 226, 18))
 >x : Symbol(x, Decl(keyofAndIndexedAccess.ts, 226, 7))
->a : Symbol(a)
+>a : Symbol(a, Decl(keyofAndIndexedAccess.ts, 226, 18))
 
     x.b;  // string | undefined
->x.b : Symbol(b)
+>x.b : Symbol(b, Decl(keyofAndIndexedAccess.ts, 226, 24))
 >x : Symbol(x, Decl(keyofAndIndexedAccess.ts, 226, 7))
->b : Symbol(b)
+>b : Symbol(b, Decl(keyofAndIndexedAccess.ts, 226, 24))
 
     x.c;  // boolean | undefined
->x.c : Symbol(c)
+>x.c : Symbol(c, Decl(keyofAndIndexedAccess.ts, 226, 40))
 >x : Symbol(x, Decl(keyofAndIndexedAccess.ts, 226, 7))
->c : Symbol(c)
+>c : Symbol(c, Decl(keyofAndIndexedAccess.ts, 226, 40))
 }
 
 function f72(func: <T, U, K extends keyof T | keyof U>(x: T, y: U, k: K) => (T & U)[K]) {
@@ -1951,11 +1951,11 @@ class AnotherSampleClass<T> extends SampleClass<T & Foo> {
 
         this.props.foo.concat;
 >this.props.foo.concat : Symbol(String.concat, Decl(lib.d.ts, --, --))
->this.props.foo : Symbol(foo)
+>this.props.foo : Symbol(foo, Decl(keyofAndIndexedAccess.ts, 536, 15))
 >this.props : Symbol(SampleClass.props, Decl(keyofAndIndexedAccess.ts, 529, 22))
 >this : Symbol(AnotherSampleClass, Decl(keyofAndIndexedAccess.ts, 540, 54))
 >props : Symbol(SampleClass.props, Decl(keyofAndIndexedAccess.ts, 529, 22))
->foo : Symbol(foo)
+>foo : Symbol(foo, Decl(keyofAndIndexedAccess.ts, 536, 15))
 >concat : Symbol(String.concat, Decl(lib.d.ts, --, --))
     }
 }
diff --git a/tests/baselines/reference/mappedTypeModifiers.symbols b/tests/baselines/reference/mappedTypeModifiers.symbols
index 2aa6492d99f..363345a2e55 100644
--- a/tests/baselines/reference/mappedTypeModifiers.symbols
+++ b/tests/baselines/reference/mappedTypeModifiers.symbols
@@ -364,9 +364,9 @@ function f1(x: Partial<Foo>) {
 >Foo : Symbol(Foo, Decl(mappedTypeModifiers.ts, 74, 30))
 
     x.prop; // ok
->x.prop : Symbol(prop)
+>x.prop : Symbol(prop, Decl(mappedTypeModifiers.ts, 76, 12))
 >x : Symbol(x, Decl(mappedTypeModifiers.ts, 78, 12))
->prop : Symbol(prop)
+>prop : Symbol(prop, Decl(mappedTypeModifiers.ts, 76, 12))
 
     (x["other"] || 0).toFixed();
 >(x["other"] || 0).toFixed : Symbol(Number.toFixed, Decl(lib.d.ts, --, --))
@@ -381,9 +381,9 @@ function f2(x: Readonly<Foo>) {
 >Foo : Symbol(Foo, Decl(mappedTypeModifiers.ts, 74, 30))
 
     x.prop; // ok
->x.prop : Symbol(prop)
+>x.prop : Symbol(prop, Decl(mappedTypeModifiers.ts, 76, 12))
 >x : Symbol(x, Decl(mappedTypeModifiers.ts, 83, 12))
->prop : Symbol(prop)
+>prop : Symbol(prop, Decl(mappedTypeModifiers.ts, 76, 12))
 
     x["other"].toFixed();
 >x["other"].toFixed : Symbol(Number.toFixed, Decl(lib.d.ts, --, --))
@@ -398,9 +398,9 @@ function f3(x: Boxified<Foo>) {
 >Foo : Symbol(Foo, Decl(mappedTypeModifiers.ts, 74, 30))
 
     x.prop; // ok
->x.prop : Symbol(prop)
+>x.prop : Symbol(prop, Decl(mappedTypeModifiers.ts, 76, 12))
 >x : Symbol(x, Decl(mappedTypeModifiers.ts, 88, 12))
->prop : Symbol(prop)
+>prop : Symbol(prop, Decl(mappedTypeModifiers.ts, 76, 12))
 
     x["other"].x.toFixed();
 >x["other"].x.toFixed : Symbol(Number.toFixed, Decl(lib.d.ts, --, --))
@@ -419,9 +419,9 @@ function f4(x: { [P in keyof Foo]: Foo[P] }) {
 >P : Symbol(P, Decl(mappedTypeModifiers.ts, 93, 18))
 
     x.prop; // ok
->x.prop : Symbol(prop)
+>x.prop : Symbol(prop, Decl(mappedTypeModifiers.ts, 76, 12))
 >x : Symbol(x, Decl(mappedTypeModifiers.ts, 93, 12))
->prop : Symbol(prop)
+>prop : Symbol(prop, Decl(mappedTypeModifiers.ts, 76, 12))
 
     x["other"].toFixed();
 >x["other"].toFixed : Symbol(Number.toFixed, Decl(lib.d.ts, --, --))
diff --git a/tests/baselines/reference/mappedTypes2.symbols b/tests/baselines/reference/mappedTypes2.symbols
index 7d9727daedd..9100c408ee9 100644
--- a/tests/baselines/reference/mappedTypes2.symbols
+++ b/tests/baselines/reference/mappedTypes2.symbols
@@ -313,16 +313,16 @@ function f5(shape: Shape) {
     let name = p.name.get();
 >name : Symbol(name, Decl(mappedTypes2.ts, 84, 7))
 >p.name.get : Symbol(get, Decl(mappedTypes2.ts, 11, 17))
->p.name : Symbol(name)
+>p.name : Symbol(name, Decl(mappedTypes2.ts, 35, 17))
 >p : Symbol(p, Decl(mappedTypes2.ts, 83, 9))
->name : Symbol(name)
+>name : Symbol(name, Decl(mappedTypes2.ts, 35, 17))
 >get : Symbol(get, Decl(mappedTypes2.ts, 11, 17))
 
     p.width.set(42);
 >p.width.set : Symbol(set, Decl(mappedTypes2.ts, 12, 13))
->p.width : Symbol(width)
+>p.width : Symbol(width, Decl(mappedTypes2.ts, 36, 17))
 >p : Symbol(p, Decl(mappedTypes2.ts, 83, 9))
->width : Symbol(width)
+>width : Symbol(width, Decl(mappedTypes2.ts, 36, 17))
 >set : Symbol(set, Decl(mappedTypes2.ts, 12, 13))
 }
 
@@ -334,19 +334,19 @@ function f6(shape: DeepReadonly<Shape>) {
 
     let name = shape.name;  // string
 >name : Symbol(name, Decl(mappedTypes2.ts, 89, 7))
->shape.name : Symbol(name)
+>shape.name : Symbol(name, Decl(mappedTypes2.ts, 35, 17))
 >shape : Symbol(shape, Decl(mappedTypes2.ts, 88, 12))
->name : Symbol(name)
+>name : Symbol(name, Decl(mappedTypes2.ts, 35, 17))
 
     let location = shape.location;  // DeepReadonly<Point>
 >location : Symbol(location, Decl(mappedTypes2.ts, 90, 7))
->shape.location : Symbol(location)
+>shape.location : Symbol(location, Decl(mappedTypes2.ts, 38, 19))
 >shape : Symbol(shape, Decl(mappedTypes2.ts, 88, 12))
->location : Symbol(location)
+>location : Symbol(location, Decl(mappedTypes2.ts, 38, 19))
 
     let x = location.x;  // number
 >x : Symbol(x, Decl(mappedTypes2.ts, 91, 7))
->location.x : Symbol(x)
+>location.x : Symbol(x, Decl(mappedTypes2.ts, 30, 17))
 >location : Symbol(location, Decl(mappedTypes2.ts, 90, 7))
->x : Symbol(x)
+>x : Symbol(x, Decl(mappedTypes2.ts, 30, 17))
 }
diff --git a/tests/baselines/reference/mappedTypes3.symbols b/tests/baselines/reference/mappedTypes3.symbols
index 683c764f0f4..74b3f3d783a 100644
--- a/tests/baselines/reference/mappedTypes3.symbols
+++ b/tests/baselines/reference/mappedTypes3.symbols
@@ -71,17 +71,17 @@ function f1(b: Bacon) {
     let isPerfect = bb.isPerfect.value;
 >isPerfect : Symbol(isPerfect, Decl(mappedTypes3.ts, 23, 7))
 >bb.isPerfect.value : Symbol(Box.value, Decl(mappedTypes3.ts, 0, 14))
->bb.isPerfect : Symbol(isPerfect)
+>bb.isPerfect : Symbol(isPerfect, Decl(mappedTypes3.ts, 11, 17))
 >bb : Symbol(bb, Decl(mappedTypes3.ts, 22, 7))
->isPerfect : Symbol(isPerfect)
+>isPerfect : Symbol(isPerfect, Decl(mappedTypes3.ts, 11, 17))
 >value : Symbol(Box.value, Decl(mappedTypes3.ts, 0, 14))
 
     let weight = bb.weight.value;
 >weight : Symbol(weight, Decl(mappedTypes3.ts, 24, 7))
 >bb.weight.value : Symbol(Box.value, Decl(mappedTypes3.ts, 0, 14))
->bb.weight : Symbol(weight)
+>bb.weight : Symbol(weight, Decl(mappedTypes3.ts, 12, 23))
 >bb : Symbol(bb, Decl(mappedTypes3.ts, 22, 7))
->weight : Symbol(weight)
+>weight : Symbol(weight, Decl(mappedTypes3.ts, 12, 23))
 >value : Symbol(Box.value, Decl(mappedTypes3.ts, 0, 14))
 }
 
diff --git a/tests/baselines/reference/typeVariableTypeGuards.symbols b/tests/baselines/reference/typeVariableTypeGuards.symbols
index fa94cfd9462..d201d0538a1 100644
--- a/tests/baselines/reference/typeVariableTypeGuards.symbols
+++ b/tests/baselines/reference/typeVariableTypeGuards.symbols
@@ -23,16 +23,16 @@ class A<P extends Partial<Foo>> {
 >doSomething : Symbol(A.doSomething, Decl(typeVariableTypeGuards.ts, 7, 22))
 
         this.props.foo && this.props.foo()
->this.props.foo : Symbol(foo)
+>this.props.foo : Symbol(foo, Decl(typeVariableTypeGuards.ts, 2, 15))
 >this.props : Symbol(A.props, Decl(typeVariableTypeGuards.ts, 6, 33))
 >this : Symbol(A, Decl(typeVariableTypeGuards.ts, 4, 1))
 >props : Symbol(A.props, Decl(typeVariableTypeGuards.ts, 6, 33))
->foo : Symbol(foo)
->this.props.foo : Symbol(foo)
+>foo : Symbol(foo, Decl(typeVariableTypeGuards.ts, 2, 15))
+>this.props.foo : Symbol(foo, Decl(typeVariableTypeGuards.ts, 2, 15))
 >this.props : Symbol(A.props, Decl(typeVariableTypeGuards.ts, 6, 33))
 >this : Symbol(A, Decl(typeVariableTypeGuards.ts, 4, 1))
 >props : Symbol(A.props, Decl(typeVariableTypeGuards.ts, 6, 33))
->foo : Symbol(foo)
+>foo : Symbol(foo, Decl(typeVariableTypeGuards.ts, 2, 15))
     }
 }
 

From 98893efa118f89009bed5afdc77f67849a8b517e Mon Sep 17 00:00:00 2001
From: Andy Hanson <anhans@microsoft.com>
Date: Thu, 25 May 2017 09:00:52 -0700
Subject: [PATCH 30/56] findAllRefs: Replace 'interface State' and
 'createState' with just 'class State'

---
 src/services/findAllReferences.ts | 108 +++++++++++++++---------------
 1 file changed, 54 insertions(+), 54 deletions(-)

diff --git a/src/services/findAllReferences.ts b/src/services/findAllReferences.ts
index efc6a6f6ed1..833d9ec95f2 100644
--- a/src/services/findAllReferences.ts
+++ b/src/services/findAllReferences.ts
@@ -386,7 +386,7 @@ namespace ts.FindAllReferences.Core {
         const searchMeaning = getIntersectingMeaningFromDeclarations(getMeaningFromLocation(node), symbol.declarations);
 
         const result: SymbolAndEntries[] = [];
-        const state = createState(sourceFiles, node, checker, cancellationToken, searchMeaning, options, result);
+        const state = new State(sourceFiles, node, checker, cancellationToken, searchMeaning, options, result);
         const search = state.createSearch(node, symbol, /*comingFrom*/ undefined, { allSearchSymbols: populateSearchSymbolSet(symbol, node, checker, options.implementations) });
 
         // Try to get the smallest valid scope that we can limit our search to;
@@ -446,35 +446,18 @@ namespace ts.FindAllReferences.Core {
      * Holds all state needed for the finding references.
      * Unlike `Search`, there is only one `State`.
      */
-    interface State extends Options {
+    class State {
         /** True if we're searching for constructor references. */
         readonly isForConstructor: boolean;
 
-        readonly sourceFiles: SourceFile[];
-        readonly checker: TypeChecker;
-        readonly cancellationToken: CancellationToken;
-        readonly searchMeaning: SemanticMeaning;
-
         /** Cache for `explicitlyinheritsFrom`. */
-        readonly inheritsFromCache: Map<boolean>;
+        readonly inheritsFromCache = createMap<boolean>();
 
-        /** Gets every place to look for references of an exported symbols. See `ImportsResult` in `importTracker.ts` for more documentation. */
-        getImportSearches(exportSymbol: Symbol, exportInfo: ExportInfo): ImportsResult;
+        private readonly symbolIdToReferences: Entry[][] = [];
+        // Source file ID → symbol ID → Whether the symbol has been searched for in the source file.
+        private readonly sourceFileToSeenSymbols: Array<Array<true>> = [];
 
-        /** @param allSearchSymbols set of additinal symbols for use by `includes`. */
-        createSearch(location: Node, symbol: Symbol, comingFrom: ImportExport | undefined, searchOptions?: { text?: string, allSearchSymbols?: Symbol[] }): Search;
-
-        /**
-         * Callback to add references for a particular searched symbol.
-         * This initializes a reference group, so only call this if you will add at least one reference.
-         */
-        referenceAdder(searchSymbol: Symbol, searchLocation: Node): (node: Node) => void;
-
-        /** Add a reference with no associated definition. */
-        addStringOrCommentReference(fileName: string, textSpan: TextSpan): void;
-
-        /** Returns `true` the first time we search for a symbol in a file and `false` afterwards. */
-        markSearchedSymbol(sourceFile: SourceFile, symbol: Symbol): boolean;
+        private importTracker: ImportTracker | undefined;
 
         /**
          * Type nodes can contain multiple references to the same type. For example:
@@ -483,7 +466,7 @@ namespace ts.FindAllReferences.Core {
          * duplicate entries would be returned here as each of the type references is part of
          * the same implementation. For that reason, check before we add a new entry.
          */
-        markSeenContainingTypeReference(containingTypeReference: Node): boolean;
+        readonly markSeenContainingTypeReference: (containingTypeReference: Node) => boolean;
 
         /**
          * It's possible that we will encounter the right side of `export { foo as bar } from "x";` more than once.
@@ -496,33 +479,44 @@ namespace ts.FindAllReferences.Core {
          * But another reference to it may appear in the same source file.
          * See `tests/cases/fourslash/transitiveExportImports3.ts`.
          */
-        markSeenReExportRHS(rhs: Identifier): boolean;
-    }
+        readonly markSeenReExportRHS: (rhs: Identifier) => boolean;
 
-    function createState(sourceFiles: SourceFile[], originalLocation: Node, checker: TypeChecker, cancellationToken: CancellationToken, searchMeaning: SemanticMeaning, options: Options, result: Push<SymbolAndEntries>): State {
-        const symbolIdToReferences: Entry[][] = [];
-        const inheritsFromCache = createMap<boolean>();
-        // Source file ID → symbol ID → Whether the symbol has been searched for in the source file.
-        const sourceFileToSeenSymbols: Array<Array<true>> = [];
-        const isForConstructor = originalLocation.kind === SyntaxKind.ConstructorKeyword;
-        let importTracker: ImportTracker | undefined;
+        readonly findInStrings?: boolean;
+        readonly findInComments?: boolean;
+        readonly isForRename?: boolean;
+        readonly implementations?: boolean;
 
-        return {
-            ...options,
-            sourceFiles, isForConstructor, checker, cancellationToken, searchMeaning, inheritsFromCache, getImportSearches, createSearch, referenceAdder, addStringOrCommentReference,
-            markSearchedSymbol, markSeenContainingTypeReference: nodeSeenTracker(), markSeenReExportRHS: nodeSeenTracker(),
-        };
+        constructor(
+            readonly sourceFiles: SourceFile[],
+            originalLocation: Node,
+            readonly checker: TypeChecker,
+            readonly cancellationToken: CancellationToken,
+            readonly searchMeaning: SemanticMeaning,
+            options: Options,
+            private readonly result: Push<SymbolAndEntries>) {
 
-        function getImportSearches(exportSymbol: Symbol, exportInfo: ExportInfo): ImportsResult {
-            if (!importTracker) importTracker = createImportTracker(sourceFiles, checker, cancellationToken);
-            return importTracker(exportSymbol, exportInfo, options.isForRename);
+            this.findInStrings = options.findInStrings;
+            this.findInComments = options.findInComments;
+            this.isForRename = options.isForRename;
+            this.implementations = options.implementations;
+
+            this.isForConstructor = originalLocation.kind === SyntaxKind.ConstructorKeyword;
+            this.markSeenContainingTypeReference = nodeSeenTracker();
+            this.markSeenReExportRHS = nodeSeenTracker();
         }
 
-        function createSearch(location: Node, symbol: Symbol, comingFrom: ImportExport, searchOptions: { text?: string, allSearchSymbols?: Symbol[] } = {}): Search {
+        /** Gets every place to look for references of an exported symbols. See `ImportsResult` in `importTracker.ts` for more documentation. */
+        getImportSearches(exportSymbol: Symbol, exportInfo: ExportInfo): ImportsResult {
+            if (!this.importTracker) this.importTracker = createImportTracker(this.sourceFiles, this.checker, this.cancellationToken);
+            return this.importTracker(exportSymbol, exportInfo, this.isForRename);
+        }
+
+        /** @param allSearchSymbols set of additinal symbols for use by `includes`. */
+        createSearch(location: Node, symbol: Symbol, comingFrom: ImportExport | undefined, searchOptions: { text?: string, allSearchSymbols?: Symbol[] } = {}): Search {
             // Note: if this is an external module symbol, the name doesn't include quotes.
-            const { text = stripQuotes(getDeclaredName(checker, symbol, location)), allSearchSymbols = undefined } = searchOptions;
+            const { text = stripQuotes(getDeclaredName(this.checker, symbol, location)), allSearchSymbols = undefined } = searchOptions;
             const escapedText = escapeIdentifier(text);
-            const parents = options.implementations && getParentSymbolsOfPropertyAccess(location, symbol, checker);
+            const parents = this.implementations && getParentSymbolsOfPropertyAccess(location, symbol, this.checker);
             return { location, symbol, comingFrom, text, escapedText, parents, includes };
 
             function includes(referenceSymbol: Symbol): boolean {
@@ -530,27 +524,33 @@ namespace ts.FindAllReferences.Core {
             }
         }
 
-        function referenceAdder(referenceSymbol: Symbol, searchLocation: Node): (node: Node) => void {
-            const symbolId = getSymbolId(referenceSymbol);
-            let references = symbolIdToReferences[symbolId];
+        /**
+         * Callback to add references for a particular searched symbol.
+         * This initializes a reference group, so only call this if you will add at least one reference.
+         */
+        referenceAdder(searchSymbol: Symbol, searchLocation: Node): (node: Node) => void {
+            const symbolId = getSymbolId(searchSymbol);
+            let references = this.symbolIdToReferences[symbolId];
             if (!references) {
-                references = symbolIdToReferences[symbolId] = [];
-                result.push({ definition: { type: "symbol", symbol: referenceSymbol, node: searchLocation }, references });
+                references = this.symbolIdToReferences[symbolId] = [];
+                this.result.push({ definition: { type: "symbol", symbol: searchSymbol, node: searchLocation }, references });
             }
             return node => references.push(nodeEntry(node));
         }
 
-        function addStringOrCommentReference(fileName: string, textSpan: TextSpan): void {
-            result.push({
+        /** Add a reference with no associated definition. */
+        addStringOrCommentReference(fileName: string, textSpan: TextSpan): void {
+            this.result.push({
                 definition: undefined,
                 references: [{ type: "span", fileName, textSpan }]
             });
         }
 
-        function markSearchedSymbol(sourceFile: SourceFile, symbol: Symbol): boolean {
+        /** Returns `true` the first time we search for a symbol in a file and `false` afterwards. */
+        markSearchedSymbol(sourceFile: SourceFile, symbol: Symbol): boolean {
             const sourceId = getNodeId(sourceFile);
             const symbolId = getSymbolId(symbol);
-            const seenSymbols = sourceFileToSeenSymbols[sourceId] || (sourceFileToSeenSymbols[sourceId] = []);
+            const seenSymbols = this.sourceFileToSeenSymbols[sourceId] || (this.sourceFileToSeenSymbols[sourceId] = []);
             return !seenSymbols[symbolId] && (seenSymbols[symbolId] = true);
         }
     }

From 528a59fdde73c3d435dbb9bdce1163fe1303b8ad Mon Sep 17 00:00:00 2001
From: Andy Hanson <anhans@microsoft.com>
Date: Thu, 25 May 2017 10:23:04 -0700
Subject: [PATCH 31/56] Clean up instance variables

---
 src/services/findAllReferences.ts | 59 +++++++++++--------------------
 1 file changed, 20 insertions(+), 39 deletions(-)

diff --git a/src/services/findAllReferences.ts b/src/services/findAllReferences.ts
index 833d9ec95f2..f3b20637acd 100644
--- a/src/services/findAllReferences.ts
+++ b/src/services/findAllReferences.ts
@@ -386,7 +386,7 @@ namespace ts.FindAllReferences.Core {
         const searchMeaning = getIntersectingMeaningFromDeclarations(getMeaningFromLocation(node), symbol.declarations);
 
         const result: SymbolAndEntries[] = [];
-        const state = new State(sourceFiles, node, checker, cancellationToken, searchMeaning, options, result);
+        const state = new State(sourceFiles, /*isForConstructor*/ node.kind === SyntaxKind.ConstructorKeyword, checker, cancellationToken, searchMeaning, options, result);
         const search = state.createSearch(node, symbol, /*comingFrom*/ undefined, { allSearchSymbols: populateSearchSymbolSet(symbol, node, checker, options.implementations) });
 
         // Try to get the smallest valid scope that we can limit our search to;
@@ -447,18 +447,9 @@ namespace ts.FindAllReferences.Core {
      * Unlike `Search`, there is only one `State`.
      */
     class State {
-        /** True if we're searching for constructor references. */
-        readonly isForConstructor: boolean;
-
         /** Cache for `explicitlyinheritsFrom`. */
         readonly inheritsFromCache = createMap<boolean>();
 
-        private readonly symbolIdToReferences: Entry[][] = [];
-        // Source file ID → symbol ID → Whether the symbol has been searched for in the source file.
-        private readonly sourceFileToSeenSymbols: Array<Array<true>> = [];
-
-        private importTracker: ImportTracker | undefined;
-
         /**
          * Type nodes can contain multiple references to the same type. For example:
          *      let x: Foo & (Foo & Bar) = ...
@@ -466,7 +457,7 @@ namespace ts.FindAllReferences.Core {
          * duplicate entries would be returned here as each of the type references is part of
          * the same implementation. For that reason, check before we add a new entry.
          */
-        readonly markSeenContainingTypeReference: (containingTypeReference: Node) => boolean;
+        readonly markSeenContainingTypeReference = nodeSeenTracker();
 
         /**
          * It's possible that we will encounter the right side of `export { foo as bar } from "x";` more than once.
@@ -479,36 +470,23 @@ namespace ts.FindAllReferences.Core {
          * But another reference to it may appear in the same source file.
          * See `tests/cases/fourslash/transitiveExportImports3.ts`.
          */
-        readonly markSeenReExportRHS: (rhs: Identifier) => boolean;
-
-        readonly findInStrings?: boolean;
-        readonly findInComments?: boolean;
-        readonly isForRename?: boolean;
-        readonly implementations?: boolean;
+        readonly markSeenReExportRHS = nodeSeenTracker();
 
         constructor(
             readonly sourceFiles: SourceFile[],
-            originalLocation: Node,
+            /** True if we're searching for constructor references. */
+            readonly isForConstructor: boolean,
             readonly checker: TypeChecker,
             readonly cancellationToken: CancellationToken,
             readonly searchMeaning: SemanticMeaning,
-            options: Options,
-            private readonly result: Push<SymbolAndEntries>) {
-
-            this.findInStrings = options.findInStrings;
-            this.findInComments = options.findInComments;
-            this.isForRename = options.isForRename;
-            this.implementations = options.implementations;
-
-            this.isForConstructor = originalLocation.kind === SyntaxKind.ConstructorKeyword;
-            this.markSeenContainingTypeReference = nodeSeenTracker();
-            this.markSeenReExportRHS = nodeSeenTracker();
-        }
+            readonly options: Options,
+            private readonly result: Push<SymbolAndEntries>) {}
 
+        private importTracker: ImportTracker | undefined;
         /** Gets every place to look for references of an exported symbols. See `ImportsResult` in `importTracker.ts` for more documentation. */
         getImportSearches(exportSymbol: Symbol, exportInfo: ExportInfo): ImportsResult {
             if (!this.importTracker) this.importTracker = createImportTracker(this.sourceFiles, this.checker, this.cancellationToken);
-            return this.importTracker(exportSymbol, exportInfo, this.isForRename);
+            return this.importTracker(exportSymbol, exportInfo, this.options.isForRename);
         }
 
         /** @param allSearchSymbols set of additinal symbols for use by `includes`. */
@@ -516,7 +494,7 @@ namespace ts.FindAllReferences.Core {
             // Note: if this is an external module symbol, the name doesn't include quotes.
             const { text = stripQuotes(getDeclaredName(this.checker, symbol, location)), allSearchSymbols = undefined } = searchOptions;
             const escapedText = escapeIdentifier(text);
-            const parents = this.implementations && getParentSymbolsOfPropertyAccess(location, symbol, this.checker);
+            const parents = this.options.implementations && getParentSymbolsOfPropertyAccess(location, symbol, this.checker);
             return { location, symbol, comingFrom, text, escapedText, parents, includes };
 
             function includes(referenceSymbol: Symbol): boolean {
@@ -524,6 +502,7 @@ namespace ts.FindAllReferences.Core {
             }
         }
 
+        private readonly symbolIdToReferences: Entry[][] = [];
         /**
          * Callback to add references for a particular searched symbol.
          * This initializes a reference group, so only call this if you will add at least one reference.
@@ -546,6 +525,8 @@ namespace ts.FindAllReferences.Core {
             });
         }
 
+        // Source file ID → symbol ID → Whether the symbol has been searched for in the source file.
+        private readonly sourceFileToSeenSymbols: Array<Array<true>> = [];
         /** Returns `true` the first time we search for a symbol in a file and `false` afterwards. */
         markSearchedSymbol(sourceFile: SourceFile, symbol: Symbol): boolean {
             const sourceId = getNodeId(sourceFile);
@@ -580,7 +561,7 @@ namespace ts.FindAllReferences.Core {
                     break;
                 case ExportKind.Default:
                     // Search for a property access to '.default'. This can't be renamed.
-                    indirectSearch = state.isForRename ? undefined : state.createSearch(exportLocation, exportSymbol, ImportExport.Export, { text: "default" });
+                    indirectSearch = state.options.isForRename ? undefined : state.createSearch(exportLocation, exportSymbol, ImportExport.Export, { text: "default" });
                     break;
                 case ExportKind.ExportEquals:
                     break;
@@ -806,7 +787,7 @@ namespace ts.FindAllReferences.Core {
             return;
         }
 
-        for (const position of getPossibleSymbolReferencePositions(sourceFile, search.text, container, /*fullStart*/ state.findInComments || container.jsDoc !== undefined)) {
+        for (const position of getPossibleSymbolReferencePositions(sourceFile, search.text, container, /*fullStart*/ state.options.findInComments || container.jsDoc !== undefined)) {
             getReferencesAtLocation(sourceFile, position, search, state);
         }
     }
@@ -818,7 +799,7 @@ namespace ts.FindAllReferences.Core {
             // This wasn't the start of a token.  Check to see if it might be a
             // match in a comment or string if that's what the caller is asking
             // for.
-            if (!state.implementations && (state.findInStrings && isInString(sourceFile, position) || state.findInComments && isInNonReferenceComment(sourceFile, position))) {
+            if (!state.options.implementations && (state.options.findInStrings && isInString(sourceFile, position) || state.options.findInComments && isInNonReferenceComment(sourceFile, position))) {
                 // In the case where we're looking inside comments/strings, we don't have
                 // an actual definition.  So just use 'undefined' here.  Features like
                 // 'Rename' won't care (as they ignore the definitions), and features like
@@ -884,7 +865,7 @@ namespace ts.FindAllReferences.Core {
                 addRef();
             }
 
-            if (!state.isForRename && state.markSeenReExportRHS(name)) {
+            if (!state.options.isForRename && state.markSeenReExportRHS(name)) {
                 addReference(name, referenceSymbol, name, state);
             }
         }
@@ -895,7 +876,7 @@ namespace ts.FindAllReferences.Core {
         }
 
         // For `export { foo as bar }`, rename `foo`, but not `bar`.
-        if (!(referenceLocation === propertyName && state.isForRename)) {
+        if (!(referenceLocation === propertyName && state.options.isForRename)) {
             const exportKind = (referenceLocation as Identifier).originalKeywordKind === ts.SyntaxKind.DefaultKeyword ? ExportKind.Default : ExportKind.Named;
             const exportInfo = getExportInfo(referenceSymbol, exportKind, state.checker);
             Debug.assert(!!exportInfo);
@@ -937,7 +918,7 @@ namespace ts.FindAllReferences.Core {
         const { symbol } = importOrExport;
 
         if (importOrExport.kind === ImportExport.Import) {
-            if (!state.isForRename || importOrExport.isNamedImport) {
+            if (!state.options.isForRename || importOrExport.isNamedImport) {
                 searchForImportedSymbol(symbol, state);
             }
         }
@@ -963,7 +944,7 @@ namespace ts.FindAllReferences.Core {
 
     function addReference(referenceLocation: Node, relatedSymbol: Symbol, searchLocation: Node, state: State): void {
         const addRef = state.referenceAdder(relatedSymbol, searchLocation);
-        if (state.implementations) {
+        if (state.options.implementations) {
             addImplementationReferences(referenceLocation, addRef, state);
         }
         else {

From 2e6f31f8e0fca508772d804417bf23677b17953e Mon Sep 17 00:00:00 2001
From: Mohamed Hegazy <mhegazy@microsoft.com>
Date: Thu, 25 May 2017 12:23:15 -0700
Subject: [PATCH 32/56] Use tslint@latest (#16049)

* Use tslint@latest

* use latest gulp-typescript
---
 package.json | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/package.json b/package.json
index ea3262902b1..c62fa46853b 100644
--- a/package.json
+++ b/package.json
@@ -59,7 +59,7 @@
         "gulp-insert": "latest",
         "gulp-newer": "latest",
         "gulp-sourcemaps": "latest",
-        "gulp-typescript": "3.1.5",
+        "gulp-typescript": "latest",
         "into-stream": "latest",
         "istanbul": "latest",
         "jake": "latest",
@@ -74,7 +74,7 @@
         "through2": "latest",
         "travis-fold": "latest",
         "ts-node": "latest",
-        "tslint": "next",
+        "tslint": "latest",
         "typescript": "next"
     },
     "scripts": {

From d052bb83caaee1f4024ecf8dfa12fa720544db3e Mon Sep 17 00:00:00 2001
From: Andy <anhans@microsoft.com>
Date: Thu, 25 May 2017 13:30:27 -0700
Subject: [PATCH 33/56] Add project telemetry (#16050)

* Add project telemetry

* Respond to some PR comments

* Wrap event in a TelemetryEvent payload

* Replace paths with empty string instead of removing them entirely

* Add "version" property to payload

* Add telemetry for typeAcquisition settings

* Add "files", "include", "exclude", and "compileOnSave"

* Convert typingsOptions include and exclude to booleanss

* Add "extends", "configFileName", and "projectType"

* configFileName: Use "other" instead of undefined

* Add "languageServiceEnabled" telemetry
---
 Jakefile.js                                   |   1 +
 src/compiler/commandLineParser.ts             |  67 +++-
 src/compiler/core.ts                          |  12 +
 src/harness/tsconfig.json                     |   3 +-
 src/harness/unittests/telemetry.ts            | 291 ++++++++++++++++++
 .../unittests/tsserverProjectSystem.ts        |   4 +-
 src/harness/unittests/typingsInstaller.ts     |  28 +-
 src/server/editorServices.ts                  | 103 ++++++-
 src/server/project.ts                         |  16 +-
 src/server/session.ts                         |  11 +-
 src/server/utilities.ts                       |   5 +-
 11 files changed, 505 insertions(+), 36 deletions(-)
 create mode 100644 src/harness/unittests/telemetry.ts

diff --git a/Jakefile.js b/Jakefile.js
index 577ade2ef69..8ba4bd2f4e1 100644
--- a/Jakefile.js
+++ b/Jakefile.js
@@ -129,6 +129,7 @@ var harnessSources = harnessCoreSources.concat([
     "initializeTSConfig.ts",
     "printer.ts",
     "textChanges.ts",
+    "telemetry.ts",
     "transform.ts",
     "customTransforms.ts",
 ].map(function (f) {
diff --git a/src/compiler/commandLineParser.ts b/src/compiler/commandLineParser.ts
index 88687357115..e612378671d 100644
--- a/src/compiler/commandLineParser.ts
+++ b/src/compiler/commandLineParser.ts
@@ -692,8 +692,7 @@ namespace ts {
         return typeAcquisition;
     }
 
-    /* @internal */
-    export function getOptionNameMap(): OptionNameMap {
+    function getOptionNameMap(): OptionNameMap {
         if (optionNameMapCache) {
             return optionNameMapCache;
         }
@@ -746,7 +745,6 @@ namespace ts {
         const options: CompilerOptions = {};
         const fileNames: string[] = [];
         const errors: Diagnostic[] = [];
-        const { optionNameMap, shortOptionNames } = getOptionNameMap();
 
         parseStrings(commandLine);
         return {
@@ -758,21 +756,13 @@ namespace ts {
         function parseStrings(args: string[]) {
             let i = 0;
             while (i < args.length) {
-                let s = args[i];
+                const s = args[i];
                 i++;
                 if (s.charCodeAt(0) === CharacterCodes.at) {
                     parseResponseFile(s.slice(1));
                 }
                 else if (s.charCodeAt(0) === CharacterCodes.minus) {
-                    s = s.slice(s.charCodeAt(1) === CharacterCodes.minus ? 2 : 1).toLowerCase();
-
-                    // Try to translate short option names to their full equivalents.
-                    const short = shortOptionNames.get(s);
-                    if (short !== undefined) {
-                        s = short;
-                    }
-
-                    const opt = optionNameMap.get(s);
+                    const opt = getOptionFromName(s.slice(s.charCodeAt(1) === CharacterCodes.minus ? 2 : 1), /*allowShort*/ true);
                     if (opt) {
                         if (opt.isTSConfigOnly) {
                             errors.push(createCompilerDiagnostic(Diagnostics.Option_0_can_only_be_specified_in_tsconfig_json_file, opt.name));
@@ -860,6 +850,19 @@ namespace ts {
         }
     }
 
+    function getOptionFromName(optionName: string, allowShort = false): CommandLineOption | undefined {
+        optionName = optionName.toLowerCase();
+        const { optionNameMap, shortOptionNames } = getOptionNameMap();
+        // Try to translate short option names to their full equivalents.
+        if (allowShort) {
+            const short = shortOptionNames.get(optionName);
+            if (short !== undefined) {
+                optionName = short;
+            }
+        }
+        return optionNameMap.get(optionName);
+    }
+
     /**
      * Read tsconfig.json file
      * @param fileName The path to the config file
@@ -1705,4 +1708,42 @@ namespace ts {
     function caseInsensitiveKeyMapper(key: string) {
         return key.toLowerCase();
     }
+
+    /**
+     * Produces a cleaned version of compiler options with personally identifiying info (aka, paths) removed.
+     * Also converts enum values back to strings.
+     */
+    /* @internal */
+    export function convertCompilerOptionsForTelemetry(opts: ts.CompilerOptions): ts.CompilerOptions {
+        const out: ts.CompilerOptions = {};
+        for (const key in opts) if (opts.hasOwnProperty(key)) {
+            const type = getOptionFromName(key);
+            if (type !== undefined) { // Ignore unknown options
+                out[key] = getOptionValueWithEmptyStrings(opts[key], type);
+            }
+        }
+        return out;
+    }
+
+    function getOptionValueWithEmptyStrings(value: any, option: CommandLineOption): {} {
+        switch (option.type) {
+            case "object": // "paths". Can't get any useful information from the value since we blank out strings, so just return "".
+                return "";
+            case "string": // Could be any arbitrary string -- use empty string instead.
+                return "";
+            case "number": // Allow numbers, but be sure to check it's actually a number.
+                return typeof value === "number" ? value : "";
+            case "boolean":
+                return typeof value === "boolean" ? value : "";
+            case "list":
+                const elementType = (option as CommandLineOptionOfListType).element;
+                return ts.isArray(value) ? value.map(v => getOptionValueWithEmptyStrings(v, elementType)) : "";
+            default:
+                return ts.forEachEntry(option.type, (optionEnumValue, optionStringValue) => {
+                    if (optionEnumValue === value) {
+                        return optionStringValue;
+                    }
+                });
+        }
+    }
 }
diff --git a/src/compiler/core.ts b/src/compiler/core.ts
index 52a7b5f5a7a..d1d21e94694 100644
--- a/src/compiler/core.ts
+++ b/src/compiler/core.ts
@@ -521,6 +521,18 @@ namespace ts {
         return result || array;
     }
 
+    export function mapDefined<T>(array: ReadonlyArray<T>, mapFn: (x: T, i: number) => T | undefined): ReadonlyArray<T> {
+        const result: T[] = [];
+        for (let i = 0; i < array.length; i++) {
+            const item = array[i];
+            const mapped = mapFn(item, i);
+            if (mapped !== undefined) {
+                result.push(mapped);
+            }
+        }
+        return result;
+    }
+
     /**
      * Computes the first matching span of elements and returns a tuple of the first span
      * and the remaining elements.
diff --git a/src/harness/tsconfig.json b/src/harness/tsconfig.json
index d752c0f235b..6553f3667a7 100644
--- a/src/harness/tsconfig.json
+++ b/src/harness/tsconfig.json
@@ -127,6 +127,7 @@
         "./unittests/printer.ts",
         "./unittests/transform.ts",
         "./unittests/customTransforms.ts",
-        "./unittests/textChanges.ts"
+        "./unittests/textChanges.ts",
+        "./unittests/telemetry.ts"
     ]
 }
diff --git a/src/harness/unittests/telemetry.ts b/src/harness/unittests/telemetry.ts
new file mode 100644
index 00000000000..d3811edf251
--- /dev/null
+++ b/src/harness/unittests/telemetry.ts
@@ -0,0 +1,291 @@
+/// <reference path="../harness.ts" />
+/// <reference path="./tsserverProjectSystem.ts" />
+
+namespace ts.projectSystem {
+    describe("project telemetry", () => {
+        it("does nothing for inferred project", () => {
+            const file = makeFile("/a.js");
+            const et = new EventTracker([file]);
+            et.service.openClientFile(file.path);
+            assert.equal(et.getEvents().length, 0);
+        });
+        it("only sends an event once", () => {
+            const file = makeFile("/a.ts");
+            const tsconfig = makeFile("/tsconfig.json", {});
+
+            const et = new EventTracker([file, tsconfig]);
+            et.service.openClientFile(file.path);
+            et.assertProjectInfoTelemetryEvent({});
+
+            et.service.closeClientFile(file.path);
+            checkNumberOfProjects(et.service, { configuredProjects: 0 });
+
+            et.service.openClientFile(file.path);
+            checkNumberOfProjects(et.service, { configuredProjects: 1 });
+
+            assert.equal(et.getEvents().length, 0);
+        });
+
+        it("counts files by extension", () => {
+            const files = ["ts.ts", "tsx.tsx", "moo.ts", "dts.d.ts", "jsx.jsx", "js.js", "badExtension.badExtension"].map(f => makeFile(`/src/${f}`));
+            const notIncludedFile = makeFile("/bin/ts.js");
+            const compilerOptions: ts.CompilerOptions = { allowJs: true };
+            const tsconfig = makeFile("/tsconfig.json", { compilerOptions, include: ["src"] });
+
+            const et = new EventTracker([...files, notIncludedFile, tsconfig]);
+            et.service.openClientFile(files[0].path);
+            et.assertProjectInfoTelemetryEvent({
+                fileStats: { ts: 2, tsx: 1, js: 1, jsx: 1, dts: 1 },
+                compilerOptions,
+                include: true,
+            });
+        });
+
+        it("works with external project", () => {
+            const file1 = makeFile("/a.ts");
+            const et = new EventTracker([file1]);
+            const compilerOptions: ts.CompilerOptions = { strict: true };
+
+            const projectFileName = "foo.csproj";
+
+            open();
+
+            // TODO: Apparently compilerOptions is mutated, so have to repeat it here!
+            et.assertProjectInfoTelemetryEvent({
+                compilerOptions: { strict: true },
+                compileOnSave: true,
+                // These properties can't be present for an external project, so they are undefined instead of false.
+                extends: undefined,
+                files: undefined,
+                include: undefined,
+                exclude: undefined,
+                configFileName: "other",
+                projectType: "external",
+            });
+
+            // Also test that opening an external project only sends an event once.
+
+            et.service.closeExternalProject(projectFileName);
+            checkNumberOfProjects(et.service, { externalProjects: 0 });
+
+            open();
+            assert.equal(et.getEvents().length, 0);
+
+            function open(): void {
+                et.service.openExternalProject({
+                    rootFiles: toExternalFiles([file1.path]),
+                    options: compilerOptions,
+                    projectFileName: projectFileName,
+                });
+                checkNumberOfProjects(et.service, { externalProjects: 1 });
+            }
+        });
+
+        it("does not expose paths", () => {
+            const file = makeFile("/a.ts");
+
+            const compilerOptions: ts.CompilerOptions = {
+                project: "",
+                outFile: "hunter2.js",
+                outDir: "hunter2",
+                rootDir: "hunter2",
+                baseUrl: "hunter2",
+                rootDirs: ["hunter2"],
+                typeRoots: ["hunter2"],
+                types: ["hunter2"],
+                sourceRoot: "hunter2",
+                mapRoot: "hunter2",
+                jsxFactory: "hunter2",
+                out: "hunter2",
+                reactNamespace: "hunter2",
+                charset: "hunter2",
+                locale: "hunter2",
+                declarationDir: "hunter2",
+                paths: {
+                    "*": ["hunter2"],
+                },
+
+                // Boolean / number options get through
+                declaration: true,
+
+                // List of string enum gets through -- but only if legitimately a member of the enum
+                lib: ["es6", "dom", "hunter2"],
+
+                // Sensitive data doesn't get through even if sent to an option of safe type
+                checkJs: "hunter2" as any as boolean,
+            };
+            const safeCompilerOptions: ts.CompilerOptions = {
+                project: "",
+                outFile: "",
+                outDir: "",
+                rootDir: "",
+                baseUrl: "",
+                rootDirs: [""],
+                typeRoots: [""],
+                types: [""],
+                sourceRoot: "",
+                mapRoot: "",
+                jsxFactory: "",
+                out: "",
+                reactNamespace: "",
+                charset: "",
+                locale: "",
+                declarationDir: "",
+                paths: "" as any,
+
+                declaration: true,
+
+                lib: ["es6", "dom"],
+
+                checkJs: "" as any as boolean,
+            };
+            (compilerOptions as any).unknownCompilerOption = "hunter2"; // These are always ignored.
+            const tsconfig = makeFile("/tsconfig.json", { compilerOptions, files: ["/a.ts"] });
+
+            const et = new EventTracker([file, tsconfig]);
+            et.service.openClientFile(file.path);
+
+            et.assertProjectInfoTelemetryEvent({
+                compilerOptions: safeCompilerOptions,
+                files: true,
+            });
+        });
+
+        it("sends telemetry for extends, files, include, exclude, and compileOnSave", () => {
+            const file = makeFile("/hunter2/a.ts");
+            const tsconfig = makeFile("/tsconfig.json", {
+                compilerOptions: {},
+                extends: "hunter2.json",
+                files: ["hunter2/a.ts"],
+                include: ["hunter2"],
+                exclude: ["hunter2"],
+                compileOnSave: true,
+            });
+
+            const et = new EventTracker([tsconfig, file]);
+            et.service.openClientFile(file.path);
+            et.assertProjectInfoTelemetryEvent({
+                extends: true,
+                files: true,
+                include: true,
+                exclude: true,
+                compileOnSave: true,
+            });
+        });
+
+        const autoJsCompilerOptions = {
+            // Apparently some options are added by default.
+            allowJs: true,
+            allowSyntheticDefaultImports: true,
+            maxNodeModuleJsDepth: 2,
+            skipLibCheck: true,
+        };
+
+        it("sends telemetry for typeAcquisition settings", () => {
+            const file = makeFile("/a.js");
+            const jsconfig = makeFile("/jsconfig.json", {
+                compilerOptions: {},
+                typeAcquisition: {
+                    enable: true,
+                    enableAutoDiscovery: false,
+                    include: ["hunter2", "hunter3"],
+                    exclude: [],
+                },
+            });
+            const et = new EventTracker([jsconfig, file]);
+            et.service.openClientFile(file.path);
+            et.assertProjectInfoTelemetryEvent({
+                fileStats: fileStats({ js: 1 }),
+                compilerOptions: autoJsCompilerOptions,
+                typeAcquisition: {
+                    enable: true,
+                    include: true,
+                    exclude: false,
+                },
+                configFileName: "jsconfig.json",
+            });
+        });
+
+        it("detects whether language service was disabled", () => {
+            const file = makeFile("/a.js");
+            const tsconfig = makeFile("/jsconfig.json", {});
+            const et = new EventTracker([tsconfig, file]);
+            et.host.getFileSize = () => server.maxProgramSizeForNonTsFiles + 1;
+            et.service.openClientFile(file.path);
+            et.getEvent<server.ProjectLanguageServiceStateEvent>(server.ProjectLanguageServiceStateEvent, /*mayBeMore*/ true);
+            et.assertProjectInfoTelemetryEvent({
+                fileStats: fileStats({ js: 1 }),
+                compilerOptions: autoJsCompilerOptions,
+                configFileName: "jsconfig.json",
+                typeAcquisition: {
+                    enable: true,
+                    include: false,
+                    exclude: false,
+                },
+                languageServiceEnabled: false,
+            });
+        });
+    });
+
+    class EventTracker {
+        private events: server.ProjectServiceEvent[] = [];
+        readonly service: TestProjectService;
+        readonly host: projectSystem.TestServerHost;
+
+        constructor(files: projectSystem.FileOrFolder[]) {
+            this.host = createServerHost(files);
+            this.service = createProjectService(this.host, {
+                eventHandler: event => {
+                    this.events.push(event);
+                },
+            });
+        }
+
+        getEvents(): ReadonlyArray<server.ProjectServiceEvent> {
+            const events = this.events;
+            this.events = [];
+            return events;
+        }
+
+        assertProjectInfoTelemetryEvent(partial: Partial<server.ProjectInfoTelemetryEventData>): void {
+            assert.deepEqual(this.getEvent<server.ProjectInfoTelemetryEvent>(ts.server.ProjectInfoTelemetryEvent), makePayload(partial));
+        }
+
+        getEvent<T extends server.ProjectServiceEvent>(eventName: T["eventName"], mayBeMore = false): T["data"] {
+            if (mayBeMore) assert(this.events.length !== 0); else assert.equal(this.events.length, 1);
+            const event = this.events.shift();
+            assert.equal(event.eventName, eventName);
+            return event.data;
+        }
+    }
+
+    function makePayload(partial: Partial<server.ProjectInfoTelemetryEventData>): server.ProjectInfoTelemetryEventData {
+        return {
+            fileStats: fileStats({ ts: 1 }),
+            compilerOptions: {},
+            extends: false,
+            files: false,
+            include: false,
+            exclude: false,
+            compileOnSave: false,
+            typeAcquisition: {
+                enable: false,
+                exclude: false,
+                include: false,
+            },
+            configFileName: "tsconfig.json",
+            projectType: "configured",
+            languageServiceEnabled: true,
+            version: ts.version,
+            ...partial
+        };
+    }
+
+    function makeFile(path: string, content: {} = ""): projectSystem.FileOrFolder {
+        return { path, content: typeof content === "string" ? "" : JSON.stringify(content) };
+    }
+
+    function fileStats(nonZeroStats: Partial<server.FileStats>): server.FileStats {
+        return { ts: 0, tsx: 0, dts: 0, js: 0, jsx: 0, ...nonZeroStats };
+    }
+}
diff --git a/src/harness/unittests/tsserverProjectSystem.ts b/src/harness/unittests/tsserverProjectSystem.ts
index efa92490300..6f898e7f4a6 100644
--- a/src/harness/unittests/tsserverProjectSystem.ts
+++ b/src/harness/unittests/tsserverProjectSystem.ts
@@ -2234,7 +2234,7 @@ namespace ts.projectSystem {
 
             let lastEvent: server.ProjectLanguageServiceStateEvent;
             const session = createSession(host, /*typingsInstaller*/ undefined, e => {
-                if (e.eventName === server.ConfigFileDiagEvent || e.eventName === server.ContextEvent) {
+                if (e.eventName === server.ConfigFileDiagEvent || e.eventName === server.ContextEvent || e.eventName === server.ProjectInfoTelemetryEvent) {
                     return;
                 }
                 assert.equal(e.eventName, server.ProjectLanguageServiceStateEvent);
@@ -2284,7 +2284,7 @@ namespace ts.projectSystem {
                 filePath === f2.path ? server.maxProgramSizeForNonTsFiles + 1 : originalGetFileSize.call(host, filePath);
             let lastEvent: server.ProjectLanguageServiceStateEvent;
             const session = createSession(host, /*typingsInstaller*/ undefined, e => {
-                if (e.eventName === server.ConfigFileDiagEvent) {
+                if (e.eventName === server.ConfigFileDiagEvent || e.eventName === server.ProjectInfoTelemetryEvent) {
                     return;
                 }
                 assert.equal(e.eventName, server.ProjectLanguageServiceStateEvent);
diff --git a/src/harness/unittests/typingsInstaller.ts b/src/harness/unittests/typingsInstaller.ts
index af95874a32c..699b1807428 100644
--- a/src/harness/unittests/typingsInstaller.ts
+++ b/src/harness/unittests/typingsInstaller.ts
@@ -44,7 +44,7 @@ namespace ts.projectSystem {
         });
     }
 
-    import typingsName = server.typingsInstaller.typingsName;
+    import typingsName = TI.typingsName;
 
     describe("local module", () => {
         it("should not be picked up", () => {
@@ -73,7 +73,7 @@ namespace ts.projectSystem {
                 constructor() {
                     super(host, { typesRegistry: createTypesRegistry("config"), globalTypingsCacheLocation: typesCache });
                 }
-                installWorker(_requestId: number, _args: string[], _cwd: string, _cb: server.typingsInstaller.RequestCompletedAction) {
+                installWorker(_requestId: number, _args: string[], _cwd: string, _cb: TI.RequestCompletedAction) {
                     assert(false, "should not be called");
                 }
             })();
@@ -121,7 +121,7 @@ namespace ts.projectSystem {
                 constructor() {
                     super(host, { typesRegistry: createTypesRegistry("jquery") });
                 }
-                installWorker(_requestId: number, _args: string[], _cwd: string, cb: server.typingsInstaller.RequestCompletedAction) {
+                installWorker(_requestId: number, _args: string[], _cwd: string, cb: TI.RequestCompletedAction) {
                     const installedTypings = ["@types/jquery"];
                     const typingFiles = [jquery];
                     executeCommand(this, host, installedTypings, typingFiles, cb);
@@ -165,7 +165,7 @@ namespace ts.projectSystem {
                 constructor() {
                     super(host, { typesRegistry: createTypesRegistry("jquery") });
                 }
-                installWorker(_requestId: number, _args: string[], _cwd: string, cb: server.typingsInstaller.RequestCompletedAction) {
+                installWorker(_requestId: number, _args: string[], _cwd: string, cb: TI.RequestCompletedAction) {
                     const installedTypings = ["@types/jquery"];
                     const typingFiles = [jquery];
                     executeCommand(this, host, installedTypings, typingFiles, cb);
@@ -672,7 +672,7 @@ namespace ts.projectSystem {
                 constructor() {
                     super(host, { globalTypingsCacheLocation: "/tmp", typesRegistry: createTypesRegistry("jquery") });
                 }
-                installWorker(_requestId: number, _args: string[], _cwd: string, cb: server.typingsInstaller.RequestCompletedAction) {
+                installWorker(_requestId: number, _args: string[], _cwd: string, cb: TI.RequestCompletedAction) {
                     const installedTypings = ["@types/jquery"];
                     const typingFiles = [jqueryDTS];
                     executeCommand(this, host, installedTypings, typingFiles, cb);
@@ -718,7 +718,7 @@ namespace ts.projectSystem {
                 constructor() {
                     super(host, { globalTypingsCacheLocation: "/tmp", typesRegistry: createTypesRegistry("jquery") });
                 }
-                installWorker(_requestId: number, _args: string[], _cwd: string, cb: server.typingsInstaller.RequestCompletedAction) {
+                installWorker(_requestId: number, _args: string[], _cwd: string, cb: TI.RequestCompletedAction) {
                     const installedTypings = ["@types/jquery"];
                     const typingFiles = [jqueryDTS];
                     executeCommand(this, host, installedTypings, typingFiles, cb);
@@ -765,7 +765,7 @@ namespace ts.projectSystem {
                 constructor() {
                     super(host, { globalTypingsCacheLocation: "/tmp", typesRegistry: createTypesRegistry("jquery") });
                 }
-                installWorker(_requestId: number, _args: string[], _cwd: string, cb: server.typingsInstaller.RequestCompletedAction) {
+                installWorker(_requestId: number, _args: string[], _cwd: string, cb: TI.RequestCompletedAction) {
                     const installedTypings = ["@types/jquery"];
                     const typingFiles = [jqueryDTS];
                     executeCommand(this, host, installedTypings, typingFiles, cb);
@@ -808,7 +808,7 @@ namespace ts.projectSystem {
                 constructor() {
                     super(host, { globalTypingsCacheLocation: cachePath, typesRegistry: createTypesRegistry("commander") });
                 }
-                installWorker(_requestId: number, _args: string[], _cwd: string, cb: server.typingsInstaller.RequestCompletedAction) {
+                installWorker(_requestId: number, _args: string[], _cwd: string, cb: TI.RequestCompletedAction) {
                     const installedTypings = ["@types/commander"];
                     const typingFiles = [commander];
                     executeCommand(this, host, installedTypings, typingFiles, cb);
@@ -849,7 +849,7 @@ namespace ts.projectSystem {
                 constructor() {
                     super(host, { globalTypingsCacheLocation: cachePath, typesRegistry: createTypesRegistry("node", "commander") });
                 }
-                installWorker(_requestId: number, _args: string[], _cwd: string, cb: server.typingsInstaller.RequestCompletedAction) {
+                installWorker(_requestId: number, _args: string[], _cwd: string, cb: TI.RequestCompletedAction) {
                     const installedTypings = ["@types/node", "@types/commander"];
                     const typingFiles = [node, commander];
                     executeCommand(this, host, installedTypings, typingFiles, cb);
@@ -888,7 +888,7 @@ namespace ts.projectSystem {
                 constructor() {
                     super(host, { globalTypingsCacheLocation: "/tmp", typesRegistry: createTypesRegistry("foo") });
                 }
-                installWorker(_requestId: number, _args: string[], _cwd: string, cb: server.typingsInstaller.RequestCompletedAction) {
+                installWorker(_requestId: number, _args: string[], _cwd: string, cb: TI.RequestCompletedAction) {
                     executeCommand(this, host, ["foo"], [], cb);
                 }
             })();
@@ -996,7 +996,7 @@ namespace ts.projectSystem {
                 constructor() {
                     super(host, { globalTypingsCacheLocation: "/tmp" }, { isEnabled: () => true, writeLine: msg => messages.push(msg) });
                 }
-                installWorker(_requestId: number, _args: string[], _cwd: string, _cb: server.typingsInstaller.RequestCompletedAction) {
+                installWorker(_requestId: number, _args: string[], _cwd: string, _cb: TI.RequestCompletedAction) {
                     assert(false, "runCommand should not be invoked");
                 }
             })();
@@ -1060,7 +1060,7 @@ namespace ts.projectSystem {
                 constructor() {
                     super(host, { globalTypingsCacheLocation: cachePath, typesRegistry: createTypesRegistry("commander") });
                 }
-                installWorker(_requestId: number, _args: string[], _cwd: string, cb: server.typingsInstaller.RequestCompletedAction) {
+                installWorker(_requestId: number, _args: string[], _cwd: string, cb: TI.RequestCompletedAction) {
                     const installedTypings = ["@types/commander"];
                     const typingFiles = [commander];
                     executeCommand(this, host, installedTypings, typingFiles, cb);
@@ -1110,7 +1110,7 @@ namespace ts.projectSystem {
                 constructor() {
                     super(host, { globalTypingsCacheLocation: cachePath, typesRegistry: createTypesRegistry("commander") });
                 }
-                installWorker(_requestId: number, _args: string[], _cwd: string, cb: server.typingsInstaller.RequestCompletedAction) {
+                installWorker(_requestId: number, _args: string[], _cwd: string, cb: TI.RequestCompletedAction) {
                     const installedTypings = ["@types/commander"];
                     const typingFiles = [commander];
                     executeCommand(this, host, installedTypings, typingFiles, cb);
@@ -1157,7 +1157,7 @@ namespace ts.projectSystem {
                 constructor() {
                     super(host, { globalTypingsCacheLocation: cachePath, typesRegistry: createTypesRegistry("commander") });
                 }
-                installWorker(_requestId: number, _args: string[], _cwd: string, cb: server.typingsInstaller.RequestCompletedAction) {
+                installWorker(_requestId: number, _args: string[], _cwd: string, cb: TI.RequestCompletedAction) {
                     executeCommand(this, host, "", [], cb);
                 }
                 sendResponse(response: server.SetTypings | server.InvalidateCachedTypings | server.BeginInstallTypes | server.EndInstallTypes) {
diff --git a/src/server/editorServices.ts b/src/server/editorServices.ts
index d8322f5e7c5..7c0e0a0fb92 100644
--- a/src/server/editorServices.ts
+++ b/src/server/editorServices.ts
@@ -13,6 +13,7 @@ namespace ts.server {
     export const ContextEvent = "context";
     export const ConfigFileDiagEvent = "configFileDiag";
     export const ProjectLanguageServiceStateEvent = "projectLanguageServiceState";
+    export const ProjectInfoTelemetryEvent = "projectInfo";
 
     export interface ContextEvent {
         eventName: typeof ContextEvent;
@@ -29,7 +30,52 @@ namespace ts.server {
         data: { project: Project, languageServiceEnabled: boolean };
     }
 
-    export type ProjectServiceEvent = ContextEvent | ConfigFileDiagEvent | ProjectLanguageServiceStateEvent;
+    /** This will be converted to the payload of a protocol.TelemetryEvent in session.defaultEventHandler. */
+    export interface ProjectInfoTelemetryEvent {
+        readonly eventName: typeof ProjectInfoTelemetryEvent;
+        readonly data: ProjectInfoTelemetryEventData;
+    }
+
+    export interface ProjectInfoTelemetryEventData {
+        /** Count of file extensions seen in the project. */
+        readonly fileStats: FileStats;
+        /**
+         * Any compiler options that might contain paths will be taken out.
+         * Enum compiler options will be converted to strings.
+         */
+        readonly compilerOptions: ts.CompilerOptions;
+        // "extends", "files", "include", or "exclude" will be undefined if an external config is used.
+        // Otherwise, we will use "true" if the property is present and "false" if it is missing.
+        readonly extends: boolean | undefined;
+        readonly files: boolean | undefined;
+        readonly include: boolean | undefined;
+        readonly exclude: boolean | undefined;
+        readonly compileOnSave: boolean;
+        readonly typeAcquisition: ProjectInfoTypeAcquisitionData;
+
+        readonly configFileName: "tsconfig.json" | "jsconfig.json" | "other";
+        readonly projectType: "external" | "configured";
+        readonly languageServiceEnabled: boolean;
+        /** TypeScript version used by the server. */
+        readonly version: string;
+    }
+
+    export interface ProjectInfoTypeAcquisitionData {
+        readonly enable: boolean;
+        // Actual values of include/exclude entries are scrubbed.
+        readonly include: boolean;
+        readonly exclude: boolean;
+    }
+
+    export interface FileStats {
+        readonly js: number;
+        readonly jsx: number;
+        readonly ts: number;
+        readonly tsx: number;
+        readonly dts: number;
+    }
+
+    export type ProjectServiceEvent = ContextEvent | ConfigFileDiagEvent | ProjectLanguageServiceStateEvent | ProjectInfoTelemetryEvent;
 
     export interface ProjectServiceEventHandler {
         (event: ProjectServiceEvent): void;
@@ -345,6 +391,9 @@ namespace ts.server {
         public readonly pluginProbeLocations: ReadonlyArray<string>;
         public readonly allowLocalPluginLoads: boolean;
 
+        /** Tracks projects that we have already sent telemetry for. */
+        private readonly seenProjects = createMap<true>();
+
         constructor(opts: ProjectServiceOptions) {
             this.host = opts.host;
             this.logger = opts.logger;
@@ -934,7 +983,10 @@ namespace ts.server {
             const projectOptions: ProjectOptions = {
                 files: parsedCommandLine.fileNames,
                 compilerOptions: parsedCommandLine.options,
-                configHasFilesProperty: config["files"] !== undefined,
+                configHasExtendsProperty: config.extends !== undefined,
+                configHasFilesProperty: config.files !== undefined,
+                configHasIncludeProperty: config.include !== undefined,
+                configHasExcludeProperty: config.exclude !== undefined,
                 wildcardDirectories: createMapFromTemplate(parsedCommandLine.wildcardDirectories),
                 typeAcquisition: parsedCommandLine.typeAcquisition,
                 compileOnSave: parsedCommandLine.compileOnSave
@@ -984,9 +1036,53 @@ namespace ts.server {
 
             this.addFilesToProjectAndUpdateGraph(project, files, externalFilePropertyReader, /*clientFileName*/ undefined, typeAcquisition, /*configFileErrors*/ undefined);
             this.externalProjects.push(project);
+            this.sendProjectTelemetry(project.externalProjectName, project);
             return project;
         }
 
+        private sendProjectTelemetry(projectKey: string, project: server.ExternalProject | server.ConfiguredProject, projectOptions?: ProjectOptions): void {
+            if (this.seenProjects.has(projectKey)) {
+                return;
+            }
+            this.seenProjects.set(projectKey, true);
+
+            if (!this.eventHandler) return;
+
+            const data: ProjectInfoTelemetryEventData = {
+                fileStats: countEachFileTypes(project.getScriptInfos()),
+                compilerOptions: convertCompilerOptionsForTelemetry(project.getCompilerOptions()),
+                typeAcquisition: convertTypeAcquisition(project.getTypeAcquisition()),
+                extends: projectOptions && projectOptions.configHasExtendsProperty,
+                files: projectOptions && projectOptions.configHasFilesProperty,
+                include: projectOptions && projectOptions.configHasIncludeProperty,
+                exclude: projectOptions && projectOptions.configHasExcludeProperty,
+                compileOnSave: project.compileOnSaveEnabled,
+                configFileName: configFileName(),
+                projectType: project instanceof server.ExternalProject ? "external" : "configured",
+                languageServiceEnabled: project.languageServiceEnabled,
+                version: ts.version,
+            };
+            this.eventHandler({ eventName: ProjectInfoTelemetryEvent, data });
+
+            function configFileName(): ProjectInfoTelemetryEventData["configFileName"] {
+                if (!(project instanceof server.ConfiguredProject)) {
+                    return "other";
+                }
+
+                const configFilePath = project instanceof server.ConfiguredProject && project.getConfigFilePath();
+                const base = ts.getBaseFileName(configFilePath);
+                return base === "tsconfig.json" || base === "jsconfig.json" ? base : "other";
+            }
+
+            function convertTypeAcquisition({ enable, include, exclude }: TypeAcquisition): ProjectInfoTypeAcquisitionData {
+                return {
+                    enable,
+                    include: include !== undefined && include.length !== 0,
+                    exclude: exclude !== undefined && exclude.length !== 0,
+                };
+            }
+        }
+
         private reportConfigFileDiagnostics(configFileName: string, diagnostics: Diagnostic[], triggerFile: string) {
             if (!this.eventHandler) {
                 return;
@@ -1020,6 +1116,7 @@ namespace ts.server {
             project.watchTypeRoots((project, path) => this.onTypeRootFileChanged(project, path));
 
             this.configuredProjects.push(project);
+            this.sendProjectTelemetry(project.getConfigFilePath(), project, projectOptions);
             return project;
         }
 
@@ -1052,7 +1149,7 @@ namespace ts.server {
             const conversionResult = this.convertConfigFileContentToProjectOptions(configFileName);
             const projectOptions: ProjectOptions = conversionResult.success
                 ? conversionResult.projectOptions
-                : { files: [], compilerOptions: {}, typeAcquisition: { enable: false } };
+                : { files: [], compilerOptions: {}, configHasExtendsProperty: false, configHasFilesProperty: false, configHasIncludeProperty: false, configHasExcludeProperty: false, typeAcquisition: { enable: false } };
             const project = this.createAndAddConfiguredProject(configFileName, projectOptions, conversionResult.configFileErrors, clientFileName);
             return {
                 success: conversionResult.success,
diff --git a/src/server/project.ts b/src/server/project.ts
index 7dc4388bf39..0646497acc5 100644
--- a/src/server/project.ts
+++ b/src/server/project.ts
@@ -13,7 +13,8 @@ namespace ts.server {
         External
     }
 
-    function countEachFileTypes(infos: ScriptInfo[]): { js: number, jsx: number, ts: number, tsx: number, dts: number } {
+    /* @internal */
+    export function countEachFileTypes(infos: ScriptInfo[]): FileStats {
         const result = { js: 0, jsx: 0, ts: 0, tsx: 0, dts: 0 };
         for (const info of infos) {
             switch (info.scriptKind) {
@@ -730,6 +731,10 @@ namespace ts.server {
         }
     }
 
+    /**
+     * If a file is opened and no tsconfig (or jsconfig) is found,
+     * the file and its imports/references are put into an InferredProject.
+     */
     export class InferredProject extends Project {
 
         private static newName = (() => {
@@ -823,6 +828,11 @@ namespace ts.server {
         }
     }
 
+    /**
+     * If a file is opened, the server will look for a tsconfig (or jsconfig)
+     * and if successfull create a ConfiguredProject for it.
+     * Otherwise it will create an InferredProject.
+     */
     export class ConfiguredProject extends Project {
         private typeAcquisition: TypeAcquisition;
         private projectFileWatcher: FileWatcher;
@@ -1048,6 +1058,10 @@ namespace ts.server {
         }
     }
 
+    /**
+     * Project whose configuration is handled externally, such as in a '.csproj'.
+     * These are created only if a host explicitly calls `openExternalProject`.
+     */
     export class ExternalProject extends Project {
         private typeAcquisition: TypeAcquisition;
         constructor(public externalProjectName: string,
diff --git a/src/server/session.ts b/src/server/session.ts
index 846607cd5ca..6ec234952db 100644
--- a/src/server/session.ts
+++ b/src/server/session.ts
@@ -337,13 +337,22 @@ namespace ts.server {
                     const { triggerFile, configFileName, diagnostics } = event.data;
                     this.configFileDiagnosticEvent(triggerFile, configFileName, diagnostics);
                     break;
-                case ProjectLanguageServiceStateEvent:
+                case ProjectLanguageServiceStateEvent: {
                     const eventName: protocol.ProjectLanguageServiceStateEventName = "projectLanguageServiceState";
                     this.event<protocol.ProjectLanguageServiceStateEventBody>({
                         projectName: event.data.project.getProjectName(),
                         languageServiceEnabled: event.data.languageServiceEnabled
                     }, eventName);
                     break;
+                }
+                case ProjectInfoTelemetryEvent: {
+                    const eventName: protocol.TelemetryEventName = "telemetry";
+                    this.event<protocol.TelemetryEventBody>({
+                        telemetryEventName: event.eventName,
+                        payload: event.data,
+                    }, eventName);
+                    break;
+                }
             }
         }
 
diff --git a/src/server/utilities.ts b/src/server/utilities.ts
index ffc09f29ccd..093958b60c5 100644
--- a/src/server/utilities.ts
+++ b/src/server/utilities.ts
@@ -164,10 +164,13 @@ namespace ts.server {
     }
 
     export interface ProjectOptions {
+        configHasExtendsProperty: boolean;
         /**
          * true if config file explicitly listed files
          */
-        configHasFilesProperty?: boolean;
+        configHasFilesProperty: boolean;
+        configHasIncludeProperty: boolean;
+        configHasExcludeProperty: boolean;
         /**
          * these fields can be present in the project file
          */

From 159614315cb44bef1bfd4af9529f51c45d56008b Mon Sep 17 00:00:00 2001
From: Mohamed Hegazy <mhegazy@microsoft.com>
Date: Thu, 25 May 2017 13:23:00 -0700
Subject: [PATCH 34/56] Fix build breaks with the instrumenter

---
 Jakefile.js                 | 4 ++--
 src/harness/instrumenter.ts | 1 -
 2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/Jakefile.js b/Jakefile.js
index 8ba4bd2f4e1..f1a714c1e26 100644
--- a/Jakefile.js
+++ b/Jakefile.js
@@ -1080,7 +1080,7 @@ var loggedIOJsPath = builtLocalDirectory + 'loggedIO.js';
 file(loggedIOJsPath, [builtLocalDirectory, loggedIOpath], function () {
     var temp = builtLocalDirectory + 'temp';
     jake.mkdirP(temp);
-    var options = "--types --outdir " + temp + ' ' + loggedIOpath;
+    var options = "--target es5 --lib es6 --types --outdir " + temp + ' ' + loggedIOpath;
     var cmd = host + " " + LKGDirectory + compilerFilename + " " + options + " ";
     console.log(cmd + "\n");
     var ex = jake.createExec([cmd]);
@@ -1094,7 +1094,7 @@ file(loggedIOJsPath, [builtLocalDirectory, loggedIOpath], function () {
 
 var instrumenterPath = harnessDirectory + 'instrumenter.ts';
 var instrumenterJsPath = builtLocalDirectory + 'instrumenter.js';
-compileFile(instrumenterJsPath, [instrumenterPath], [tscFile, instrumenterPath].concat(libraryTargets), [], /*useBuiltCompiler*/ true);
+compileFile(instrumenterJsPath, [instrumenterPath], [tscFile, instrumenterPath].concat(libraryTargets), [], /*useBuiltCompiler*/ true, { lib: "es6", types: ["node"] });
 
 desc("Builds an instrumented tsc.js");
 task('tsc-instrumented', [loggedIOJsPath, instrumenterJsPath, tscFile], function () {
diff --git a/src/harness/instrumenter.ts b/src/harness/instrumenter.ts
index b8f42e7e8bd..02aba0e7661 100644
--- a/src/harness/instrumenter.ts
+++ b/src/harness/instrumenter.ts
@@ -1,4 +1,3 @@
-declare const require: any, process: any;
 const fs: any = require("fs");
 const path: any = require("path");
 

From cabe4d36060750d742a62f6cd3b27234ee83caf4 Mon Sep 17 00:00:00 2001
From: Yui T <yuisu@microsoft.com>
Date: Thu, 25 May 2017 19:49:04 -0700
Subject: [PATCH 35/56] Address PR

---
 src/compiler/binder.ts | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/src/compiler/binder.ts b/src/compiler/binder.ts
index 8870757999f..80bdeae6df5 100644
--- a/src/compiler/binder.ts
+++ b/src/compiler/binder.ts
@@ -2178,11 +2178,10 @@ namespace ts {
                 case SyntaxKind.JSDocRecordMember:
                     return bindPropertyWorker(node as JSDocRecordMember);
                 case SyntaxKind.JSDocPropertyTag:
-                    let optionalType = 0;
-                    if ((node as JSDocPropertyTag).typeExpression.type.kind === SyntaxKind.JSDocOptionalType) {
-                        optionalType = SymbolFlags.Optional;
-                    }
-                    return declareSymbolAndAddToSymbolTable(node as JSDocPropertyTag, SymbolFlags.Property | optionalType, SymbolFlags.PropertyExcludes);
+                    return declareSymbolAndAddToSymbolTable(node as JSDocPropertyTag,
+                        (node as JSDocPropertyTag).typeExpression && (node as JSDocPropertyTag).typeExpression.type.kind === SyntaxKind.JSDocOptionalType ?
+                            SymbolFlags.Property | SymbolFlags.Optional : SymbolFlags.Property,
+                        SymbolFlags.PropertyExcludes);
                 case SyntaxKind.JSDocFunctionType:
                     return bindFunctionOrConstructorType(<SignatureDeclaration>node);
                 case SyntaxKind.JSDocTypeLiteral:

From 4f791040fc7fa467dec2ae66bf9b0cc1b688e5e8 Mon Sep 17 00:00:00 2001
From: Yui T <yuisu@microsoft.com>
Date: Thu, 25 May 2017 20:16:52 -0700
Subject: [PATCH 36/56] Add tests and baselines

---
 .../reference/checkJsdocTypedefInParamTag1.js | 24 +++++++++++++++++++
 .../checkJsdocTypedefInParamTag1.symbols      | 17 +++++++++++++
 .../checkJsdocTypedefInParamTag1.types        | 20 ++++++++++++++++
 .../jsdoc/checkJsdocTypedefInParamTag1.ts     | 15 ++++++++++++
 4 files changed, 76 insertions(+)
 create mode 100644 tests/baselines/reference/checkJsdocTypedefInParamTag1.js
 create mode 100644 tests/baselines/reference/checkJsdocTypedefInParamTag1.symbols
 create mode 100644 tests/baselines/reference/checkJsdocTypedefInParamTag1.types
 create mode 100644 tests/cases/conformance/jsdoc/checkJsdocTypedefInParamTag1.ts

diff --git a/tests/baselines/reference/checkJsdocTypedefInParamTag1.js b/tests/baselines/reference/checkJsdocTypedefInParamTag1.js
new file mode 100644
index 00000000000..28d6a96b3f9
--- /dev/null
+++ b/tests/baselines/reference/checkJsdocTypedefInParamTag1.js
@@ -0,0 +1,24 @@
+//// [0.js]
+// @ts-check
+/**
+ * @typedef {Object} Opts
+ * @property {string} x
+ * @property {string=} y
+ * 
+ * @param {Opts} opts
+ */
+function foo(opts) {}
+
+foo({x: 'abc'});
+
+//// [0.js]
+// @ts-check
+/**
+ * @typedef {Object} Opts
+ * @property {string} x
+ * @property {string=} y
+ *
+ * @param {Opts} opts
+ */
+function foo(opts) { }
+foo({ x: 'abc' });
diff --git a/tests/baselines/reference/checkJsdocTypedefInParamTag1.symbols b/tests/baselines/reference/checkJsdocTypedefInParamTag1.symbols
new file mode 100644
index 00000000000..19672d6e52c
--- /dev/null
+++ b/tests/baselines/reference/checkJsdocTypedefInParamTag1.symbols
@@ -0,0 +1,17 @@
+=== tests/cases/conformance/jsdoc/0.js ===
+// @ts-check
+/**
+ * @typedef {Object} Opts
+ * @property {string} x
+ * @property {string=} y
+ * 
+ * @param {Opts} opts
+ */
+function foo(opts) {}
+>foo : Symbol(foo, Decl(0.js, 0, 0))
+>opts : Symbol(opts, Decl(0.js, 8, 13))
+
+foo({x: 'abc'});
+>foo : Symbol(foo, Decl(0.js, 0, 0))
+>x : Symbol(x, Decl(0.js, 10, 5))
+
diff --git a/tests/baselines/reference/checkJsdocTypedefInParamTag1.types b/tests/baselines/reference/checkJsdocTypedefInParamTag1.types
new file mode 100644
index 00000000000..ff30e8da8a8
--- /dev/null
+++ b/tests/baselines/reference/checkJsdocTypedefInParamTag1.types
@@ -0,0 +1,20 @@
+=== tests/cases/conformance/jsdoc/0.js ===
+// @ts-check
+/**
+ * @typedef {Object} Opts
+ * @property {string} x
+ * @property {string=} y
+ * 
+ * @param {Opts} opts
+ */
+function foo(opts) {}
+>foo : (opts: { x: string; y?: string; }) => void
+>opts : { x: string; y?: string; }
+
+foo({x: 'abc'});
+>foo({x: 'abc'}) : void
+>foo : (opts: { x: string; y?: string; }) => void
+>{x: 'abc'} : { x: string; }
+>x : string
+>'abc' : "abc"
+
diff --git a/tests/cases/conformance/jsdoc/checkJsdocTypedefInParamTag1.ts b/tests/cases/conformance/jsdoc/checkJsdocTypedefInParamTag1.ts
new file mode 100644
index 00000000000..261ce070cf2
--- /dev/null
+++ b/tests/cases/conformance/jsdoc/checkJsdocTypedefInParamTag1.ts
@@ -0,0 +1,15 @@
+// @allowJS: true
+// @suppressOutputPathCheck: true
+
+// @filename: 0.js
+// @ts-check
+/**
+ * @typedef {Object} Opts
+ * @property {string} x
+ * @property {string=} y
+ * 
+ * @param {Opts} opts
+ */
+function foo(opts) {}
+
+foo({x: 'abc'});
\ No newline at end of file

From 23be471def7c30dd5b2ce7959986b2259c7fb723 Mon Sep 17 00:00:00 2001
From: Yui T <yuisu@microsoft.com>
Date: Thu, 25 May 2017 21:52:23 -0700
Subject: [PATCH 37/56] Fix linting

---
 src/compiler/binder.ts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/compiler/binder.ts b/src/compiler/binder.ts
index 80bdeae6df5..ec3e8157589 100644
--- a/src/compiler/binder.ts
+++ b/src/compiler/binder.ts
@@ -1,4 +1,4 @@
-/// <reference path="utilities.ts"/>
+/// <reference path="utilities.ts"/>
 /// <reference path="parser.ts"/>
 
 /* @internal */
@@ -3596,4 +3596,4 @@ namespace ts {
                 return TransformFlags.NodeExcludes;
         }
     }
-}
+}
\ No newline at end of file

From d68038ad28d482e38626e487c22a264295dfa8de Mon Sep 17 00:00:00 2001
From: Yui T <yuisu@microsoft.com>
Date: Thu, 25 May 2017 22:34:48 -0700
Subject: [PATCH 38/56] Support bracket for optional property

---
 src/compiler/binder.ts |  2 +-
 src/compiler/parser.ts | 17 ++++++++++++-----
 src/compiler/types.ts  |  1 +
 3 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/src/compiler/binder.ts b/src/compiler/binder.ts
index ec3e8157589..d55f3650c10 100644
--- a/src/compiler/binder.ts
+++ b/src/compiler/binder.ts
@@ -2179,7 +2179,7 @@ namespace ts {
                     return bindPropertyWorker(node as JSDocRecordMember);
                 case SyntaxKind.JSDocPropertyTag:
                     return declareSymbolAndAddToSymbolTable(node as JSDocPropertyTag,
-                        (node as JSDocPropertyTag).typeExpression && (node as JSDocPropertyTag).typeExpression.type.kind === SyntaxKind.JSDocOptionalType ?
+                        (node as JSDocPropertyTag).isBracketed || ((node as JSDocPropertyTag).typeExpression && (node as JSDocPropertyTag).typeExpression.type.kind === SyntaxKind.JSDocOptionalType) ?
                             SymbolFlags.Property | SymbolFlags.Optional : SymbolFlags.Property,
                         SymbolFlags.PropertyExcludes);
                 case SyntaxKind.JSDocFunctionType:
diff --git a/src/compiler/parser.ts b/src/compiler/parser.ts
index 04209ab0924..07d4a9ada41 100644
--- a/src/compiler/parser.ts
+++ b/src/compiler/parser.ts
@@ -6631,10 +6631,7 @@ namespace ts {
                     });
                 }
 
-                function parseParamTag(atToken: AtToken, tagName: Identifier) {
-                    let typeExpression = tryParseTypeExpression();
-                    skipWhitespace();
-
+                function parseBracketNameInPropertyAndParamTag() {
                     let name: Identifier;
                     let isBracketed: boolean;
                     // Looking for something like '[foo]' or 'foo'
@@ -6653,6 +6650,14 @@ namespace ts {
                     else if (tokenIsIdentifierOrKeyword(token())) {
                         name = parseJSDocIdentifierName();
                     }
+                    return { name, isBracketed };
+                }
+
+                function parseParamTag(atToken: AtToken, tagName: Identifier) {
+                    let typeExpression = tryParseTypeExpression();
+                    skipWhitespace();
+
+                    const { name, isBracketed } = parseBracketNameInPropertyAndParamTag();
 
                     if (!name) {
                         parseErrorAtPosition(scanner.getStartPos(), 0, Diagnostics.Identifier_expected);
@@ -6709,8 +6714,9 @@ namespace ts {
                 function parsePropertyTag(atToken: AtToken, tagName: Identifier): JSDocPropertyTag {
                     const typeExpression = tryParseTypeExpression();
                     skipWhitespace();
-                    const name = parseJSDocIdentifierName();
+                    const { name, isBracketed } = parseBracketNameInPropertyAndParamTag();
                     skipWhitespace();
+
                     if (!name) {
                         parseErrorAtPosition(scanner.getStartPos(), /*length*/ 0, Diagnostics.Identifier_expected);
                         return undefined;
@@ -6721,6 +6727,7 @@ namespace ts {
                     result.tagName = tagName;
                     result.name = name;
                     result.typeExpression = typeExpression;
+                    result.isBracketed = isBracketed;
                     return finishNode(result);
                 }
 
diff --git a/src/compiler/types.ts b/src/compiler/types.ts
index 73a2e46be90..93098993754 100644
--- a/src/compiler/types.ts
+++ b/src/compiler/types.ts
@@ -2143,6 +2143,7 @@ namespace ts {
         kind: SyntaxKind.JSDocPropertyTag;
         name: Identifier;
         typeExpression: JSDocTypeExpression;
+        isBracketed: boolean;
     }
 
     export interface JSDocTypeLiteral extends JSDocType {

From 8ae2fbadd0a82a3a77e11a066bc0318e2129e480 Mon Sep 17 00:00:00 2001
From: Yui T <yuisu@microsoft.com>
Date: Thu, 25 May 2017 22:35:15 -0700
Subject: [PATCH 39/56] Add tests and baselines

---
 tests/baselines/reference/checkJsdocTypedefInParamTag1.js | 4 ++++
 .../reference/checkJsdocTypedefInParamTag1.symbols        | 6 ++++--
 .../reference/checkJsdocTypedefInParamTag1.types          | 8 +++++---
 .../conformance/jsdoc/checkJsdocTypedefInParamTag1.ts     | 2 ++
 4 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/tests/baselines/reference/checkJsdocTypedefInParamTag1.js b/tests/baselines/reference/checkJsdocTypedefInParamTag1.js
index 28d6a96b3f9..d4983bfd581 100644
--- a/tests/baselines/reference/checkJsdocTypedefInParamTag1.js
+++ b/tests/baselines/reference/checkJsdocTypedefInParamTag1.js
@@ -4,6 +4,8 @@
  * @typedef {Object} Opts
  * @property {string} x
  * @property {string=} y
+ * @property {string} [z]
+ * @property {string} [w="hi"]
  * 
  * @param {Opts} opts
  */
@@ -17,6 +19,8 @@ foo({x: 'abc'});
  * @typedef {Object} Opts
  * @property {string} x
  * @property {string=} y
+ * @property {string} [z]
+ * @property {string} [w="hi"]
  *
  * @param {Opts} opts
  */
diff --git a/tests/baselines/reference/checkJsdocTypedefInParamTag1.symbols b/tests/baselines/reference/checkJsdocTypedefInParamTag1.symbols
index 19672d6e52c..cd2455797b4 100644
--- a/tests/baselines/reference/checkJsdocTypedefInParamTag1.symbols
+++ b/tests/baselines/reference/checkJsdocTypedefInParamTag1.symbols
@@ -4,14 +4,16 @@
  * @typedef {Object} Opts
  * @property {string} x
  * @property {string=} y
+ * @property {string} [z]
+ * @property {string} [w="hi"]
  * 
  * @param {Opts} opts
  */
 function foo(opts) {}
 >foo : Symbol(foo, Decl(0.js, 0, 0))
->opts : Symbol(opts, Decl(0.js, 8, 13))
+>opts : Symbol(opts, Decl(0.js, 10, 13))
 
 foo({x: 'abc'});
 >foo : Symbol(foo, Decl(0.js, 0, 0))
->x : Symbol(x, Decl(0.js, 10, 5))
+>x : Symbol(x, Decl(0.js, 12, 5))
 
diff --git a/tests/baselines/reference/checkJsdocTypedefInParamTag1.types b/tests/baselines/reference/checkJsdocTypedefInParamTag1.types
index ff30e8da8a8..cc923e33030 100644
--- a/tests/baselines/reference/checkJsdocTypedefInParamTag1.types
+++ b/tests/baselines/reference/checkJsdocTypedefInParamTag1.types
@@ -4,16 +4,18 @@
  * @typedef {Object} Opts
  * @property {string} x
  * @property {string=} y
+ * @property {string} [z]
+ * @property {string} [w="hi"]
  * 
  * @param {Opts} opts
  */
 function foo(opts) {}
->foo : (opts: { x: string; y?: string; }) => void
->opts : { x: string; y?: string; }
+>foo : (opts: { x: string; y?: string; z?: string; w?: string; }) => void
+>opts : { x: string; y?: string; z?: string; w?: string; }
 
 foo({x: 'abc'});
 >foo({x: 'abc'}) : void
->foo : (opts: { x: string; y?: string; }) => void
+>foo : (opts: { x: string; y?: string; z?: string; w?: string; }) => void
 >{x: 'abc'} : { x: string; }
 >x : string
 >'abc' : "abc"
diff --git a/tests/cases/conformance/jsdoc/checkJsdocTypedefInParamTag1.ts b/tests/cases/conformance/jsdoc/checkJsdocTypedefInParamTag1.ts
index 261ce070cf2..80ca21bd4ff 100644
--- a/tests/cases/conformance/jsdoc/checkJsdocTypedefInParamTag1.ts
+++ b/tests/cases/conformance/jsdoc/checkJsdocTypedefInParamTag1.ts
@@ -7,6 +7,8 @@
  * @typedef {Object} Opts
  * @property {string} x
  * @property {string=} y
+ * @property {string} [z]
+ * @property {string} [w="hi"]
  * 
  * @param {Opts} opts
  */

From 2412f8c6cfaadd769af9d81a813c60c7c0768fa4 Mon Sep 17 00:00:00 2001
From: Andy <anhans@microsoft.com>
Date: Fri, 26 May 2017 07:06:11 -0700
Subject: [PATCH 40/56] Allow configurable npmLocation for typingsInstaller
 (#16084)

* Allow configurable npmLocation for typingsInstaller

* Undo "export class" changes

* Add log for npmLocation

* Log whether '--npmLocation' was provided
---
 src/server/server.ts                          | 36 +++++++++++--------
 src/server/shared.ts                          |  7 +++-
 .../typingsInstaller/nodeTypingsInstaller.ts  | 11 +++---
 3 files changed, 34 insertions(+), 20 deletions(-)

diff --git a/src/server/server.ts b/src/server/server.ts
index ed3e2dd8207..390a0f2f6f4 100644
--- a/src/server/server.ts
+++ b/src/server/server.ts
@@ -13,6 +13,7 @@ namespace ts.server {
         globalTypingsCacheLocation: string;
         logger: Logger;
         typingSafeListLocation: string;
+        npmLocation: string | undefined;
         telemetryEnabled: boolean;
         globalPlugins: string[];
         pluginProbeLocations: string[];
@@ -234,6 +235,7 @@ namespace ts.server {
             eventPort: number,
             readonly globalTypingsCacheLocation: string,
             readonly typingSafeListLocation: string,
+            private readonly npmLocation: string | undefined,
             private newLine: string) {
             this.throttledOperations = new ThrottledOperations(host);
             if (eventPort) {
@@ -278,19 +280,21 @@ namespace ts.server {
             if (this.typingSafeListLocation) {
                 args.push(Arguments.TypingSafeListLocation, this.typingSafeListLocation);
             }
+            if (this.npmLocation) {
+                args.push(Arguments.NpmLocation, this.npmLocation);
+            }
+
             const execArgv: string[] = [];
-            {
-                for (const arg of process.execArgv) {
-                    const match = /^--(debug|inspect)(=(\d+))?$/.exec(arg);
-                    if (match) {
-                        // if port is specified - use port + 1
-                        // otherwise pick a default port depending on if 'debug' or 'inspect' and use its value + 1
-                        const currentPort = match[3] !== undefined
-                            ? +match[3]
-                            : match[1] === "debug" ? 5858 : 9229;
-                        execArgv.push(`--${match[1]}=${currentPort + 1}`);
-                        break;
-                    }
+            for (const arg of process.execArgv) {
+                const match = /^--(debug|inspect)(=(\d+))?$/.exec(arg);
+                if (match) {
+                    // if port is specified - use port + 1
+                    // otherwise pick a default port depending on if 'debug' or 'inspect' and use its value + 1
+                    const currentPort = match[3] !== undefined
+                        ? +match[3]
+                        : match[1] === "debug" ? 5858 : 9229;
+                    execArgv.push(`--${match[1]}=${currentPort + 1}`);
+                    break;
                 }
             }
 
@@ -389,10 +393,10 @@ namespace ts.server {
 
     class IOSession extends Session {
         constructor(options: IOSessionOptions) {
-            const { host, installerEventPort, globalTypingsCacheLocation, typingSafeListLocation, canUseEvents } = options;
+            const { host, installerEventPort, globalTypingsCacheLocation, typingSafeListLocation, npmLocation, canUseEvents } = options;
             const typingsInstaller = disableAutomaticTypingAcquisition
                 ? undefined
-                : new NodeTypingsInstaller(telemetryEnabled, logger, host, installerEventPort, globalTypingsCacheLocation, typingSafeListLocation, host.newLine);
+                : new NodeTypingsInstaller(telemetryEnabled, logger, host, installerEventPort, globalTypingsCacheLocation, typingSafeListLocation, npmLocation, host.newLine);
 
             super({
                 host,
@@ -741,7 +745,8 @@ namespace ts.server {
         validateLocaleAndSetLanguage(localeStr, sys);
     }
 
-    const typingSafeListLocation = findArgument("--typingSafeListLocation");
+    const typingSafeListLocation = findArgument(Arguments.TypingSafeListLocation);
+    const npmLocation = findArgument(Arguments.NpmLocation);
 
     const globalPlugins = (findArgument("--globalPlugins") || "").split(",");
     const pluginProbeLocations = (findArgument("--pluginProbeLocations") || "").split(",");
@@ -760,6 +765,7 @@ namespace ts.server {
         disableAutomaticTypingAcquisition,
         globalTypingsCacheLocation: getGlobalTypingsCacheLocation(),
         typingSafeListLocation,
+        npmLocation,
         telemetryEnabled,
         logger,
         globalPlugins,
diff --git a/src/server/shared.ts b/src/server/shared.ts
index 6dcf8881927..1285eba06e1 100644
--- a/src/server/shared.ts
+++ b/src/server/shared.ts
@@ -12,13 +12,18 @@ namespace ts.server {
         export const LogFile = "--logFile";
         export const EnableTelemetry = "--enableTelemetry";
         export const TypingSafeListLocation = "--typingSafeListLocation";
+        /**
+         * This argument specifies the location of the NPM executable.
+         * typingsInstaller will run the command with `${npmLocation} install ...`.
+         */
+        export const NpmLocation = "--npmLocation";
     }
 
     export function hasArgument(argumentName: string) {
         return sys.args.indexOf(argumentName) >= 0;
     }
 
-    export function findArgument(argumentName: string) {
+    export function findArgument(argumentName: string): string | undefined {
         const index = sys.args.indexOf(argumentName);
         return index >= 0 && index < sys.args.length - 1
             ? sys.args[index + 1]
diff --git a/src/server/typingsInstaller/nodeTypingsInstaller.ts b/src/server/typingsInstaller/nodeTypingsInstaller.ts
index 1182450ce81..797962cba08 100644
--- a/src/server/typingsInstaller/nodeTypingsInstaller.ts
+++ b/src/server/typingsInstaller/nodeTypingsInstaller.ts
@@ -30,7 +30,8 @@ namespace ts.server.typingsInstaller {
         }
     }
 
-    function getNPMLocation(processName: string) {
+    /** Used if `--npmLocation` is not passed. */
+    function getDefaultNPMLocation(processName: string) {
         if (path.basename(processName).indexOf("node") === 0) {
             return `"${path.join(path.dirname(process.argv[0]), "npm")}"`;
         }
@@ -76,17 +77,18 @@ namespace ts.server.typingsInstaller {
 
         private delayedInitializationError: InitializationFailedResponse;
 
-        constructor(globalTypingsCacheLocation: string, typingSafeListLocation: string, throttleLimit: number, log: Log) {
+        constructor(globalTypingsCacheLocation: string, typingSafeListLocation: string, npmLocation: string | undefined, throttleLimit: number, log: Log) {
             super(
                 sys,
                 globalTypingsCacheLocation,
                 typingSafeListLocation ? toPath(typingSafeListLocation, "", createGetCanonicalFileName(sys.useCaseSensitiveFileNames)) : toPath("typingSafeList.json", __dirname, createGetCanonicalFileName(sys.useCaseSensitiveFileNames)),
                 throttleLimit,
                 log);
+            this.npmPath = npmLocation !== undefined ? npmLocation : getDefaultNPMLocation(process.argv[0]);
             if (this.log.isEnabled()) {
                 this.log.writeLine(`Process id: ${process.pid}`);
+                this.log.writeLine(`NPM location: ${this.npmPath} (explicit '${Arguments.NpmLocation}' ${npmLocation === undefined ? "not " : ""} provided)`);
             }
-            this.npmPath = getNPMLocation(process.argv[0]);
             ({ execSync: this.execSync } = require("child_process"));
 
             this.ensurePackageDirectoryExists(globalTypingsCacheLocation);
@@ -168,6 +170,7 @@ namespace ts.server.typingsInstaller {
     const logFilePath = findArgument(server.Arguments.LogFile);
     const globalTypingsCacheLocation = findArgument(server.Arguments.GlobalCacheLocation);
     const typingSafeListLocation = findArgument(server.Arguments.TypingSafeListLocation);
+    const npmLocation = findArgument(server.Arguments.NpmLocation);
 
     const log = new FileLog(logFilePath);
     if (log.isEnabled()) {
@@ -181,6 +184,6 @@ namespace ts.server.typingsInstaller {
         }
         process.exit(0);
     });
-    const installer = new NodeTypingsInstaller(globalTypingsCacheLocation, typingSafeListLocation, /*throttleLimit*/5, log);
+    const installer = new NodeTypingsInstaller(globalTypingsCacheLocation, typingSafeListLocation, npmLocation, /*throttleLimit*/5, log);
     installer.listen();
 }
\ No newline at end of file

From 6972766e917956d2f9c148af58d484f7d2ed1da2 Mon Sep 17 00:00:00 2001
From: Ika <ikatyang@gmail.com>
Date: Sat, 27 May 2017 00:28:56 +0800
Subject: [PATCH 41/56] Add missing undefined type for createProperty
 initializer (#16095)

---
 src/compiler/factory.ts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/compiler/factory.ts b/src/compiler/factory.ts
index 2b41f13f8a4..943d011c350 100644
--- a/src/compiler/factory.ts
+++ b/src/compiler/factory.ts
@@ -303,7 +303,7 @@ namespace ts {
             : node;
     }
 
-    export function createProperty(decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, name: string | PropertyName, questionToken: QuestionToken | undefined, type: TypeNode | undefined, initializer: Expression) {
+    export function createProperty(decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, name: string | PropertyName, questionToken: QuestionToken | undefined, type: TypeNode | undefined, initializer: Expression | undefined) {
         const node = <PropertyDeclaration>createSynthesizedNode(SyntaxKind.PropertyDeclaration);
         node.decorators = asNodeArray(decorators);
         node.modifiers = asNodeArray(modifiers);
@@ -314,7 +314,7 @@ namespace ts {
         return node;
     }
 
-    export function updateProperty(node: PropertyDeclaration, decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, name: PropertyName, type: TypeNode | undefined, initializer: Expression) {
+    export function updateProperty(node: PropertyDeclaration, decorators: Decorator[] | undefined, modifiers: Modifier[] | undefined, name: PropertyName, type: TypeNode | undefined, initializer: Expression | undefined) {
         return node.decorators !== decorators
             || node.modifiers !== modifiers
             || node.name !== name

From 3cd9f3d2d4afc1c817ea53b3e40d9598197e9aaa Mon Sep 17 00:00:00 2001
From: Andy <anhans@microsoft.com>
Date: Fri, 26 May 2017 09:52:46 -0700
Subject: [PATCH 42/56] Support services for @typedef (#16087)

* Support services for @typedef

* Ensure JSDocTypeReference has SemanticMeaning.Type

* Get SemanticMeaning right
---
 src/compiler/types.ts                         |  3 ++
 src/compiler/utilities.ts                     | 12 +++++++
 src/services/findAllReferences.ts             |  3 +-
 src/services/goToDefinition.ts                |  2 +-
 src/services/utilities.ts                     | 32 +++++++++++++------
 .../jsdocTypedefTagSemanticMeaning0.ts        | 16 ++++++++++
 .../jsdocTypedefTagSemanticMeaning1.ts        | 12 +++++++
 .../fourslash/jsdocTypedefTagServices.ts      | 28 ++++++++++++++++
 8 files changed, 97 insertions(+), 11 deletions(-)
 create mode 100644 tests/cases/fourslash/jsdocTypedefTagSemanticMeaning0.ts
 create mode 100644 tests/cases/fourslash/jsdocTypedefTagSemanticMeaning1.ts
 create mode 100644 tests/cases/fourslash/jsdocTypedefTagServices.ts

diff --git a/src/compiler/types.ts b/src/compiler/types.ts
index 73a2e46be90..c295a4c9563 100644
--- a/src/compiler/types.ts
+++ b/src/compiler/types.ts
@@ -2102,6 +2102,7 @@ namespace ts {
     }
 
     export interface JSDocTag extends Node {
+        parent: JSDoc;
         atToken: AtToken;
         tagName: Identifier;
         comment: string | undefined;
@@ -2132,6 +2133,7 @@ namespace ts {
     }
 
     export interface JSDocTypedefTag extends JSDocTag, NamedDeclaration {
+        parent: JSDoc;
         kind: SyntaxKind.JSDocTypedefTag;
         fullName?: JSDocNamespaceDeclaration | Identifier;
         name?: Identifier;
@@ -2140,6 +2142,7 @@ namespace ts {
     }
 
     export interface JSDocPropertyTag extends JSDocTag, TypeElement {
+        parent: JSDoc;
         kind: SyntaxKind.JSDocPropertyTag;
         name: Identifier;
         typeExpression: JSDocTypeExpression;
diff --git a/src/compiler/utilities.ts b/src/compiler/utilities.ts
index 22210419af7..134404c247b 100644
--- a/src/compiler/utilities.ts
+++ b/src/compiler/utilities.ts
@@ -288,6 +288,14 @@ namespace ts {
         return node.kind >= SyntaxKind.FirstJSDocNode && node.kind <= SyntaxKind.LastJSDocNode;
     }
 
+    export function isJSDoc(node: Node): node is JSDoc {
+        return node.kind === SyntaxKind.JSDocComment;
+    }
+
+    export function isJSDocTypedefTag(node: Node): node is JSDocTypedefTag {
+        return node.kind === SyntaxKind.JSDocTypedefTag;
+    }
+
     export function isJSDocTag(node: Node) {
         return node.kind >= SyntaxKind.FirstJSDocTagNode && node.kind <= SyntaxKind.LastJSDocTagNode;
     }
@@ -1551,6 +1559,10 @@ namespace ts {
     }
 
    export function getJSDocs(node: Node): (JSDoc | JSDocTag)[] {
+        if (isJSDocTypedefTag(node)) {
+            return [node.parent];
+        }
+
         let cache: (JSDoc | JSDocTag)[] = node.jsDocCache;
         if (!cache) {
             getJSDocsWorker(node);
diff --git a/src/services/findAllReferences.ts b/src/services/findAllReferences.ts
index 7877e28b6fc..df499cbd38a 100644
--- a/src/services/findAllReferences.ts
+++ b/src/services/findAllReferences.ts
@@ -784,7 +784,8 @@ namespace ts.FindAllReferences.Core {
             return;
         }
 
-        for (const position of getPossibleSymbolReferencePositions(sourceFile, search.text, container, /*fullStart*/ state.options.findInComments || container.jsDoc !== undefined)) {
+        const fullStart = state.options.findInComments || container.jsDoc !== undefined || forEach(search.symbol.declarations, d => d.kind === ts.SyntaxKind.JSDocTypedefTag);
+        for (const position of getPossibleSymbolReferencePositions(sourceFile, search.text, container, fullStart)) {
             getReferencesAtLocation(sourceFile, position, search, state);
         }
     }
diff --git a/src/services/goToDefinition.ts b/src/services/goToDefinition.ts
index 9b96f339bf6..ac60ba7942c 100644
--- a/src/services/goToDefinition.ts
+++ b/src/services/goToDefinition.ts
@@ -8,7 +8,7 @@ namespace ts.GoToDefinition {
             if (referenceFile) {
                 return [getDefinitionInfoForFileReference(comment.fileName, referenceFile.fileName)];
             }
-            return undefined;
+            // Might still be on jsdoc, so keep looking.
         }
 
         // Type reference directives
diff --git a/src/services/utilities.ts b/src/services/utilities.ts
index 2e771a73286..7a87c0939c7 100644
--- a/src/services/utilities.ts
+++ b/src/services/utilities.ts
@@ -39,13 +39,14 @@ namespace ts {
             case SyntaxKind.TypeLiteral:
                 return SemanticMeaning.Type;
 
+            case SyntaxKind.JSDocTypedefTag:
+                // If it has no name node, it shares the name with the value declaration below it.
+                return (node as JSDocTypedefTag).name === undefined ? SemanticMeaning.Value | SemanticMeaning.Type : SemanticMeaning.Type;
+
             case SyntaxKind.EnumMember:
             case SyntaxKind.ClassDeclaration:
                 return SemanticMeaning.Value | SemanticMeaning.Type;
 
-            case SyntaxKind.EnumDeclaration:
-                return SemanticMeaning.All;
-
             case SyntaxKind.ModuleDeclaration:
                 if (isAmbientModule(<ModuleDeclaration>node)) {
                     return SemanticMeaning.Namespace | SemanticMeaning.Value;
@@ -57,6 +58,7 @@ namespace ts {
                     return SemanticMeaning.Namespace;
                 }
 
+            case SyntaxKind.EnumDeclaration:
             case SyntaxKind.NamedImports:
             case SyntaxKind.ImportSpecifier:
             case SyntaxKind.ImportEqualsDeclaration:
@@ -70,7 +72,7 @@ namespace ts {
                 return SemanticMeaning.Namespace | SemanticMeaning.Value;
         }
 
-        return SemanticMeaning.Value | SemanticMeaning.Type | SemanticMeaning.Namespace;
+        return SemanticMeaning.All;
     }
 
     export function getMeaningFromLocation(node: Node): SemanticMeaning {
@@ -78,7 +80,7 @@ namespace ts {
             return SemanticMeaning.Value;
         }
         else if (node.parent.kind === SyntaxKind.ExportAssignment) {
-            return SemanticMeaning.Value | SemanticMeaning.Type | SemanticMeaning.Namespace;
+            return SemanticMeaning.All;
         }
         else if (isInRightSideOfImport(node)) {
             return getMeaningFromRightHandSideOfImportEquals(node);
@@ -162,10 +164,22 @@ namespace ts {
             node = node.parent;
         }
 
-        return node.parent.kind === SyntaxKind.TypeReference ||
-            (node.parent.kind === SyntaxKind.ExpressionWithTypeArguments && !isExpressionWithTypeArgumentsInClassExtendsClause(<ExpressionWithTypeArguments>node.parent)) ||
-            (node.kind === SyntaxKind.ThisKeyword && !isPartOfExpression(node)) ||
-            node.kind === SyntaxKind.ThisType;
+        switch (node.kind) {
+            case SyntaxKind.ThisKeyword:
+                return !isPartOfExpression(node);
+            case SyntaxKind.ThisType:
+                return true;
+        }
+
+        switch (node.parent.kind) {
+            case SyntaxKind.TypeReference:
+            case SyntaxKind.JSDocTypeReference:
+                return true;
+            case SyntaxKind.ExpressionWithTypeArguments:
+                return !isExpressionWithTypeArgumentsInClassExtendsClause(<ExpressionWithTypeArguments>node.parent);
+        }
+
+        return false;
     }
 
     export function isCallExpressionTarget(node: Node): boolean {
diff --git a/tests/cases/fourslash/jsdocTypedefTagSemanticMeaning0.ts b/tests/cases/fourslash/jsdocTypedefTagSemanticMeaning0.ts
new file mode 100644
index 00000000000..3673c86b381
--- /dev/null
+++ b/tests/cases/fourslash/jsdocTypedefTagSemanticMeaning0.ts
@@ -0,0 +1,16 @@
+///<reference path="fourslash.ts" />
+
+// @allowJs: true
+// @Filename: a.js
+
+/////** @typedef {number} [|{| "isWriteAccess": true, "isDefinition": true |}T|] */
+
+////const [|{| "isWriteAccess": true, "isDefinition": true |}T|] = 1;
+
+/////** @type {[|T|]} */
+////const n = [|T|];
+
+const [t0, v0, t1, v1] = test.ranges();
+
+verify.singleReferenceGroup("type T = number\nconst T: 1", [t0, t1]);
+verify.singleReferenceGroup("type T = number\nconst T: 1", [v0, v1]);
diff --git a/tests/cases/fourslash/jsdocTypedefTagSemanticMeaning1.ts b/tests/cases/fourslash/jsdocTypedefTagSemanticMeaning1.ts
new file mode 100644
index 00000000000..f052d4bd870
--- /dev/null
+++ b/tests/cases/fourslash/jsdocTypedefTagSemanticMeaning1.ts
@@ -0,0 +1,12 @@
+///<reference path="fourslash.ts" />
+
+// @allowJs: true
+// @Filename: a.js
+
+/////** @typedef {number} */
+////const [|{| "isWriteAccess": true, "isDefinition": true |}T|] = 1;
+
+/////** @type {[|T|]} */
+////const n = [|T|];
+
+verify.singleReferenceGroup("type T = number\nconst T: 1");
diff --git a/tests/cases/fourslash/jsdocTypedefTagServices.ts b/tests/cases/fourslash/jsdocTypedefTagServices.ts
new file mode 100644
index 00000000000..c97707e4d25
--- /dev/null
+++ b/tests/cases/fourslash/jsdocTypedefTagServices.ts
@@ -0,0 +1,28 @@
+///<reference path="fourslash.ts" />
+
+// @allowJs: true
+// @Filename: a.js
+
+/////**
+//// * Doc comment
+//// * @typedef /*def*/[|{| "isWriteAccess": true, "isDefinition": true |}Product|]
+//// * @property {string} title
+//// */
+
+/////**
+//// * @type {/*use*/[|Product|]}
+//// */
+////const product = null;
+
+const desc = `type Product = {
+    title: string;
+}`;
+
+verify.quickInfoAt("use", desc, "Doc comment");
+
+verify.goToDefinition("use", "def");
+
+verify.rangesAreOccurrences();
+verify.rangesAreDocumentHighlights();
+verify.singleReferenceGroup(desc);
+verify.rangesAreRenameLocations();

From 7ca91f86a7960d5464de669f71ec8d950c63f4fc Mon Sep 17 00:00:00 2001
From: Anders Hejlsberg <andersh@microsoft.com>
Date: Fri, 26 May 2017 10:44:11 -0700
Subject: [PATCH 43/56] Address CR feedback

---
 src/compiler/checker.ts | 33 +++++++++++++++------------------
 1 file changed, 15 insertions(+), 18 deletions(-)

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 30100332210..91ee22471aa 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -10292,29 +10292,26 @@ namespace ts {
                     // Because the anyFunctionType is internal, it should not be exposed to the user by adding
                     // it as an inference candidate. Hopefully, a better candidate will come along that does
                     // not contain anyFunctionType when we come back to this argument for its second round
-                    // of inference.
+                    // of inference. Also, we exclude inferences for silentNeverType which is used as a wildcard
+                    // when constructing types from type parameters that had no inference candidates.
                     if (source.flags & TypeFlags.ContainsAnyFunctionType || source === silentNeverType) {
                         return;
                     }
-                    for (const inference of inferences) {
-                        if (target === inference.typeParameter) {
-                            // Even if an inference is marked as fixed, we can add candidates from inferences made
-                            // from the return type of generic functions (which only happens when no other candidates
-                            // are present).
-                            if (!inference.isFixed) {
-                                if (!inference.candidates || priority < inference.priority) {
-                                    inference.candidates = [source];
-                                    inference.priority = priority;
-                                }
-                                else if (priority === inference.priority) {
-                                    inference.candidates.push(source);
-                                }
-                                if (!(priority & InferencePriority.ReturnType) && target.flags & TypeFlags.TypeParameter && !isTypeParameterAtTopLevel(originalTarget, <TypeParameter>target)) {
-                                    inference.topLevel = false;
-                                }
+                    const inference = getInferenceInfoForType(target);
+                    if (inference) {
+                        if (!inference.isFixed) {
+                            if (!inference.candidates || priority < inference.priority) {
+                                inference.candidates = [source];
+                                inference.priority = priority;
+                            }
+                            else if (priority === inference.priority) {
+                                inference.candidates.push(source);
+                            }
+                            if (!(priority & InferencePriority.ReturnType) && target.flags & TypeFlags.TypeParameter && !isTypeParameterAtTopLevel(originalTarget, <TypeParameter>target)) {
+                                inference.topLevel = false;
                             }
-                            return;
                         }
+                        return;
                     }
                 }
                 else if (getObjectFlags(source) & ObjectFlags.Reference && getObjectFlags(target) & ObjectFlags.Reference && (<TypeReference>source).target === (<TypeReference>target).target) {

From 9c102461d96fb7293b03e99d89aaa55e742c4101 Mon Sep 17 00:00:00 2001
From: Yui T <yuisu@microsoft.com>
Date: Fri, 26 May 2017 19:08:08 -0700
Subject: [PATCH 44/56] Rename parameterName to name

---
 src/compiler/parser.ts                                        | 2 +-
 src/compiler/types.ts                                         | 2 +-
 src/compiler/utilities.ts                                     | 4 ++--
 .../DocComments.parsesCorrectly.argSynonymForParamTag.json    | 2 +-
 ...ocComments.parsesCorrectly.argumentSynonymForParamTag.json | 2 +-
 .../JSDocParsing/DocComments.parsesCorrectly.oneParamTag.json | 2 +-
 .../JSDocParsing/DocComments.parsesCorrectly.paramTag1.json   | 2 +-
 .../DocComments.parsesCorrectly.paramTagBracketedName1.json   | 2 +-
 .../DocComments.parsesCorrectly.paramTagBracketedName2.json   | 2 +-
 .../DocComments.parsesCorrectly.paramTagNameThenType1.json    | 2 +-
 .../DocComments.parsesCorrectly.paramTagNameThenType2.json    | 2 +-
 .../DocComments.parsesCorrectly.paramWithoutType.json         | 2 +-
 .../DocComments.parsesCorrectly.twoParamTag2.json             | 4 ++--
 .../DocComments.parsesCorrectly.twoParamTagOnSameLine.json    | 4 ++--
 14 files changed, 17 insertions(+), 17 deletions(-)

diff --git a/src/compiler/parser.ts b/src/compiler/parser.ts
index 07d4a9ada41..cd9cd7c247d 100644
--- a/src/compiler/parser.ts
+++ b/src/compiler/parser.ts
@@ -6682,7 +6682,7 @@ namespace ts {
                     result.preParameterName = preName;
                     result.typeExpression = typeExpression;
                     result.postParameterName = postName;
-                    result.parameterName = postName || preName;
+                    result.name = postName || preName;
                     result.isBracketed = isBracketed;
                     return finishNode(result);
                 }
diff --git a/src/compiler/types.ts b/src/compiler/types.ts
index 6f602ff23af..d8d6c174c12 100644
--- a/src/compiler/types.ts
+++ b/src/compiler/types.ts
@@ -2163,7 +2163,7 @@ namespace ts {
         /** the parameter name, if provided *after* the type (JSDoc-standard) */
         postParameterName?: Identifier;
         /** the parameter name, regardless of the location it was provided */
-        parameterName: Identifier;
+        name: Identifier;
         isBracketed: boolean;
     }
 
diff --git a/src/compiler/utilities.ts b/src/compiler/utilities.ts
index 134404c247b..506d2728ffd 100644
--- a/src/compiler/utilities.ts
+++ b/src/compiler/utilities.ts
@@ -1635,7 +1635,7 @@ namespace ts {
         }
         else if (param.name.kind === SyntaxKind.Identifier) {
             const name = (param.name as Identifier).text;
-            return filter(tags, tag => tag.kind === SyntaxKind.JSDocParameterTag && tag.parameterName.text === name);
+            return filter(tags, tag => tag.kind === SyntaxKind.JSDocParameterTag && tag.name.text === name);
         }
         else {
             // TODO: it's a destructured parameter, so it should look up an "object type" series of multiple lines
@@ -1646,7 +1646,7 @@ namespace ts {
 
     /** Does the opposite of `getJSDocParameterTags`: given a JSDoc parameter, finds the parameter corresponding to it. */
     export function getParameterFromJSDoc(node: JSDocParameterTag): ParameterDeclaration | undefined {
-        const name = node.parameterName.text;
+        const name = node.name.text;
         const grandParent = node.parent!.parent!;
         Debug.assert(node.parent!.kind === SyntaxKind.JSDocComment);
         if (!isFunctionLike(grandParent)) {
diff --git a/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.argSynonymForParamTag.json b/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.argSynonymForParamTag.json
index 064a040c58f..7e4346eba68 100644
--- a/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.argSynonymForParamTag.json
+++ b/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.argSynonymForParamTag.json
@@ -34,7 +34,7 @@
                 "end": 27,
                 "text": "name1"
             },
-            "parameterName": {
+            "name": {
                 "kind": "Identifier",
                 "pos": 22,
                 "end": 27,
diff --git a/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.argumentSynonymForParamTag.json b/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.argumentSynonymForParamTag.json
index 264b5850223..e46a09e6561 100644
--- a/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.argumentSynonymForParamTag.json
+++ b/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.argumentSynonymForParamTag.json
@@ -34,7 +34,7 @@
                 "end": 32,
                 "text": "name1"
             },
-            "parameterName": {
+            "name": {
                 "kind": "Identifier",
                 "pos": 27,
                 "end": 32,
diff --git a/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.oneParamTag.json b/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.oneParamTag.json
index 9d303955ab1..af20bf8d6bb 100644
--- a/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.oneParamTag.json
+++ b/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.oneParamTag.json
@@ -34,7 +34,7 @@
                 "end": 29,
                 "text": "name1"
             },
-            "parameterName": {
+            "name": {
                 "kind": "Identifier",
                 "pos": 24,
                 "end": 29,
diff --git a/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.paramTag1.json b/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.paramTag1.json
index 1b87d268b93..5e0c3d21744 100644
--- a/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.paramTag1.json
+++ b/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.paramTag1.json
@@ -34,7 +34,7 @@
                 "end": 29,
                 "text": "name1"
             },
-            "parameterName": {
+            "name": {
                 "kind": "Identifier",
                 "pos": 24,
                 "end": 29,
diff --git a/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.paramTagBracketedName1.json b/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.paramTagBracketedName1.json
index fe01df58851..1df54fadcd7 100644
--- a/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.paramTagBracketedName1.json
+++ b/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.paramTagBracketedName1.json
@@ -34,7 +34,7 @@
                 "end": 30,
                 "text": "name1"
             },
-            "parameterName": {
+            "name": {
                 "kind": "Identifier",
                 "pos": 25,
                 "end": 30,
diff --git a/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.paramTagBracketedName2.json b/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.paramTagBracketedName2.json
index f50ce732606..5347b99be7a 100644
--- a/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.paramTagBracketedName2.json
+++ b/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.paramTagBracketedName2.json
@@ -34,7 +34,7 @@
                 "end": 31,
                 "text": "name1"
             },
-            "parameterName": {
+            "name": {
                 "kind": "Identifier",
                 "pos": 26,
                 "end": 31,
diff --git a/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.paramTagNameThenType1.json b/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.paramTagNameThenType1.json
index 70f2641fd51..204d94779b3 100644
--- a/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.paramTagNameThenType1.json
+++ b/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.paramTagNameThenType1.json
@@ -34,7 +34,7 @@
                     "end": 28
                 }
             },
-            "parameterName": {
+            "name": {
                 "kind": "Identifier",
                 "pos": 15,
                 "end": 20,
diff --git a/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.paramTagNameThenType2.json b/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.paramTagNameThenType2.json
index 4b720567cc7..7c79459768b 100644
--- a/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.paramTagNameThenType2.json
+++ b/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.paramTagNameThenType2.json
@@ -34,7 +34,7 @@
                     "end": 28
                 }
             },
-            "parameterName": {
+            "name": {
                 "kind": "Identifier",
                 "pos": 15,
                 "end": 20,
diff --git a/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.paramWithoutType.json b/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.paramWithoutType.json
index d77e80c7512..17036e3729a 100644
--- a/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.paramWithoutType.json
+++ b/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.paramWithoutType.json
@@ -24,7 +24,7 @@
                 "end": 18,
                 "text": "foo"
             },
-            "parameterName": {
+            "name": {
                 "kind": "Identifier",
                 "pos": 15,
                 "end": 18,
diff --git a/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.twoParamTag2.json b/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.twoParamTag2.json
index 16968061afc..d5d04dce69c 100644
--- a/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.twoParamTag2.json
+++ b/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.twoParamTag2.json
@@ -34,7 +34,7 @@
                 "end": 29,
                 "text": "name1"
             },
-            "parameterName": {
+            "name": {
                 "kind": "Identifier",
                 "pos": 24,
                 "end": 29,
@@ -73,7 +73,7 @@
                 "end": 55,
                 "text": "name2"
             },
-            "parameterName": {
+            "name": {
                 "kind": "Identifier",
                 "pos": 50,
                 "end": 55,
diff --git a/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.twoParamTagOnSameLine.json b/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.twoParamTagOnSameLine.json
index 8818c3a909e..4c85b2c9aed 100644
--- a/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.twoParamTagOnSameLine.json
+++ b/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.twoParamTagOnSameLine.json
@@ -34,7 +34,7 @@
                 "end": 29,
                 "text": "name1"
             },
-            "parameterName": {
+            "name": {
                 "kind": "Identifier",
                 "pos": 24,
                 "end": 29,
@@ -73,7 +73,7 @@
                 "end": 51,
                 "text": "name2"
             },
-            "parameterName": {
+            "name": {
                 "kind": "Identifier",
                 "pos": 46,
                 "end": 51,

From fe838bab2d5180d35110725a0a035ce4e8cdbe04 Mon Sep 17 00:00:00 2001
From: Yui T <yuisu@microsoft.com>
Date: Sat, 27 May 2017 19:10:53 -0700
Subject: [PATCH 45/56] Parse ts-style property tag

---
 src/compiler/parser.ts | 31 +++++++------------------------
 src/compiler/types.ts  |  4 ++++
 2 files changed, 11 insertions(+), 24 deletions(-)

diff --git a/src/compiler/parser.ts b/src/compiler/parser.ts
index cd9cd7c247d..575992ca1a1 100644
--- a/src/compiler/parser.ts
+++ b/src/compiler/parser.ts
@@ -6508,7 +6508,7 @@ namespace ts {
                             case "arg":
                             case "argument":
                             case "param":
-                                tag = parseParamTag(atToken, tagName);
+                                tag = parseParameterOrPropertyTag(atToken, tagName, /*shouldParseParamTag*/ true);
                                 break;
                             case "return":
                             case "returns":
@@ -6653,11 +6653,12 @@ namespace ts {
                     return { name, isBracketed };
                 }
 
-                function parseParamTag(atToken: AtToken, tagName: Identifier) {
+                function parseParameterOrPropertyTag(atToken: AtToken, tagName: Identifier, shouldParseParamTag: boolean): JSDocPropertyTag | JSDocParameterTag {
                     let typeExpression = tryParseTypeExpression();
                     skipWhitespace();
 
                     const { name, isBracketed } = parseBracketNameInPropertyAndParamTag();
+                    skipWhitespace();
 
                     if (!name) {
                         parseErrorAtPosition(scanner.getStartPos(), 0, Diagnostics.Identifier_expected);
@@ -6676,7 +6677,9 @@ namespace ts {
                         typeExpression = tryParseTypeExpression();
                     }
 
-                    const result = <JSDocParameterTag>createNode(SyntaxKind.JSDocParameterTag, atToken.pos);
+                    const result = shouldParseParamTag ?
+                        <JSDocParameterTag>createNode(SyntaxKind.JSDocParameterTag, atToken.pos) :
+                        <JSDocPropertyTag>createNode(SyntaxKind.JSDocPropertyTag, atToken.pos);
                     result.atToken = atToken;
                     result.tagName = tagName;
                     result.preParameterName = preName;
@@ -6711,26 +6714,6 @@ namespace ts {
                     return finishNode(result);
                 }
 
-                function parsePropertyTag(atToken: AtToken, tagName: Identifier): JSDocPropertyTag {
-                    const typeExpression = tryParseTypeExpression();
-                    skipWhitespace();
-                    const { name, isBracketed } = parseBracketNameInPropertyAndParamTag();
-                    skipWhitespace();
-
-                    if (!name) {
-                        parseErrorAtPosition(scanner.getStartPos(), /*length*/ 0, Diagnostics.Identifier_expected);
-                        return undefined;
-                    }
-
-                    const result = <JSDocPropertyTag>createNode(SyntaxKind.JSDocPropertyTag, atToken.pos);
-                    result.atToken = atToken;
-                    result.tagName = tagName;
-                    result.name = name;
-                    result.typeExpression = typeExpression;
-                    result.isBracketed = isBracketed;
-                    return finishNode(result);
-                }
-
                 function parseAugmentsTag(atToken: AtToken, tagName: Identifier): JSDocAugmentsTag {
                     const typeExpression = tryParseTypeExpression();
 
@@ -6867,7 +6850,7 @@ namespace ts {
                             return true;
                         case "prop":
                         case "property":
-                            const propertyTag = parsePropertyTag(atToken, tagName);
+                            const propertyTag = parseParameterOrPropertyTag(atToken, tagName, /*shouldParseParamTag*/ false) as JSDocPropertyTag;
                             if (propertyTag) {
                                 if (!parentTag.jsDocPropertyTags) {
                                     parentTag.jsDocPropertyTags = <NodeArray<JSDocPropertyTag>>[];
diff --git a/src/compiler/types.ts b/src/compiler/types.ts
index d8d6c174c12..ebb0f02f39d 100644
--- a/src/compiler/types.ts
+++ b/src/compiler/types.ts
@@ -2145,6 +2145,10 @@ namespace ts {
         parent: JSDoc;
         kind: SyntaxKind.JSDocPropertyTag;
         name: Identifier;
+        /** the parameter name, if provided *before* the type (TypeScript-style) */
+        preParameterName?: Identifier;
+        /** the parameter name, if provided *after* the type (JSDoc-standard) */
+        postParameterName?: Identifier;
         typeExpression: JSDocTypeExpression;
         isBracketed: boolean;
     }

From 227198fae175734acf2ea66ddee930315806bdb8 Mon Sep 17 00:00:00 2001
From: Yui T <yuisu@microsoft.com>
Date: Sat, 27 May 2017 19:11:08 -0700
Subject: [PATCH 46/56] Add tests and update baselines

---
 ...parsesCorrectly.argSynonymForParamTag.json |  4 +--
 ...sCorrectly.argumentSynonymForParamTag.json |  4 +--
 ...cComments.parsesCorrectly.oneParamTag.json |  4 +--
 ...DocComments.parsesCorrectly.paramTag1.json |  4 +--
 ...ents.parsesCorrectly.paramWithoutType.json |  4 +--
 ...Comments.parsesCorrectly.twoParamTag2.json |  6 ++--
 ...parsesCorrectly.twoParamTagOnSameLine.json |  6 ++--
 ...sCorrectly.typedefTagWithChildrenTags.json | 36 ++++++++++++-------
 .../reference/checkJsdocTypedefInParamTag1.js | 22 +++++++++++-
 .../checkJsdocTypedefInParamTag1.symbols      | 15 ++++++++
 .../checkJsdocTypedefInParamTag1.types        | 18 ++++++++++
 .../jsdoc/checkJsdocTypedefInParamTag1.ts     | 13 ++++++-
 12 files changed, 106 insertions(+), 30 deletions(-)

diff --git a/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.argSynonymForParamTag.json b/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.argSynonymForParamTag.json
index 7e4346eba68..92b9cb450e6 100644
--- a/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.argSynonymForParamTag.json
+++ b/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.argSynonymForParamTag.json
@@ -6,7 +6,7 @@
         "0": {
             "kind": "JSDocParameterTag",
             "pos": 8,
-            "end": 27,
+            "end": 28,
             "atToken": {
                 "kind": "AtToken",
                 "pos": 8,
@@ -44,6 +44,6 @@
         },
         "length": 1,
         "pos": 8,
-        "end": 27
+        "end": 28
     }
 }
\ No newline at end of file
diff --git a/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.argumentSynonymForParamTag.json b/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.argumentSynonymForParamTag.json
index e46a09e6561..f398fb3af41 100644
--- a/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.argumentSynonymForParamTag.json
+++ b/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.argumentSynonymForParamTag.json
@@ -6,7 +6,7 @@
         "0": {
             "kind": "JSDocParameterTag",
             "pos": 8,
-            "end": 32,
+            "end": 33,
             "atToken": {
                 "kind": "AtToken",
                 "pos": 8,
@@ -44,6 +44,6 @@
         },
         "length": 1,
         "pos": 8,
-        "end": 32
+        "end": 33
     }
 }
\ No newline at end of file
diff --git a/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.oneParamTag.json b/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.oneParamTag.json
index af20bf8d6bb..e70fc95367f 100644
--- a/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.oneParamTag.json
+++ b/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.oneParamTag.json
@@ -6,7 +6,7 @@
         "0": {
             "kind": "JSDocParameterTag",
             "pos": 8,
-            "end": 29,
+            "end": 30,
             "atToken": {
                 "kind": "AtToken",
                 "pos": 8,
@@ -44,6 +44,6 @@
         },
         "length": 1,
         "pos": 8,
-        "end": 29
+        "end": 30
     }
 }
\ No newline at end of file
diff --git a/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.paramTag1.json b/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.paramTag1.json
index 5e0c3d21744..0dbdd83d2ba 100644
--- a/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.paramTag1.json
+++ b/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.paramTag1.json
@@ -6,7 +6,7 @@
         "0": {
             "kind": "JSDocParameterTag",
             "pos": 8,
-            "end": 29,
+            "end": 30,
             "atToken": {
                 "kind": "AtToken",
                 "pos": 8,
@@ -44,6 +44,6 @@
         },
         "length": 1,
         "pos": 8,
-        "end": 29
+        "end": 30
     }
 }
\ No newline at end of file
diff --git a/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.paramWithoutType.json b/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.paramWithoutType.json
index 17036e3729a..2ff182483d9 100644
--- a/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.paramWithoutType.json
+++ b/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.paramWithoutType.json
@@ -6,7 +6,7 @@
         "0": {
             "kind": "JSDocParameterTag",
             "pos": 8,
-            "end": 18,
+            "end": 19,
             "atToken": {
                 "kind": "AtToken",
                 "pos": 8,
@@ -34,6 +34,6 @@
         },
         "length": 1,
         "pos": 8,
-        "end": 18
+        "end": 19
     }
 }
\ No newline at end of file
diff --git a/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.twoParamTag2.json b/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.twoParamTag2.json
index d5d04dce69c..b51ab3598e6 100644
--- a/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.twoParamTag2.json
+++ b/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.twoParamTag2.json
@@ -6,7 +6,7 @@
         "0": {
             "kind": "JSDocParameterTag",
             "pos": 8,
-            "end": 29,
+            "end": 32,
             "atToken": {
                 "kind": "AtToken",
                 "pos": 8,
@@ -45,7 +45,7 @@
         "1": {
             "kind": "JSDocParameterTag",
             "pos": 34,
-            "end": 55,
+            "end": 56,
             "atToken": {
                 "kind": "AtToken",
                 "pos": 34,
@@ -83,6 +83,6 @@
         },
         "length": 2,
         "pos": 8,
-        "end": 55
+        "end": 56
     }
 }
\ No newline at end of file
diff --git a/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.twoParamTagOnSameLine.json b/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.twoParamTagOnSameLine.json
index 4c85b2c9aed..3c20d5edcbc 100644
--- a/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.twoParamTagOnSameLine.json
+++ b/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.twoParamTagOnSameLine.json
@@ -6,7 +6,7 @@
         "0": {
             "kind": "JSDocParameterTag",
             "pos": 8,
-            "end": 29,
+            "end": 30,
             "atToken": {
                 "kind": "AtToken",
                 "pos": 8,
@@ -45,7 +45,7 @@
         "1": {
             "kind": "JSDocParameterTag",
             "pos": 30,
-            "end": 51,
+            "end": 52,
             "atToken": {
                 "kind": "AtToken",
                 "pos": 30,
@@ -83,6 +83,6 @@
         },
         "length": 2,
         "pos": 8,
-        "end": 51
+        "end": 52
     }
 }
\ No newline at end of file
diff --git a/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.typedefTagWithChildrenTags.json b/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.typedefTagWithChildrenTags.json
index 7ef64f5a971..7a8f9c4bcc9 100644
--- a/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.typedefTagWithChildrenTags.json
+++ b/tests/baselines/reference/JSDocParsing/DocComments.parsesCorrectly.typedefTagWithChildrenTags.json
@@ -82,12 +82,6 @@
                             "end": 56,
                             "text": "property"
                         },
-                        "name": {
-                            "kind": "Identifier",
-                            "pos": 66,
-                            "end": 69,
-                            "text": "age"
-                        },
                         "typeExpression": {
                             "kind": "JSDocTypeExpression",
                             "pos": 57,
@@ -97,6 +91,18 @@
                                 "pos": 58,
                                 "end": 64
                             }
+                        },
+                        "postParameterName": {
+                            "kind": "Identifier",
+                            "pos": 66,
+                            "end": 69,
+                            "text": "age"
+                        },
+                        "name": {
+                            "kind": "Identifier",
+                            "pos": 66,
+                            "end": 69,
+                            "text": "age"
                         }
                     },
                     {
@@ -114,12 +120,6 @@
                             "end": 83,
                             "text": "property"
                         },
-                        "name": {
-                            "kind": "Identifier",
-                            "pos": 93,
-                            "end": 97,
-                            "text": "name"
-                        },
                         "typeExpression": {
                             "kind": "JSDocTypeExpression",
                             "pos": 84,
@@ -129,6 +129,18 @@
                                 "pos": 85,
                                 "end": 91
                             }
+                        },
+                        "postParameterName": {
+                            "kind": "Identifier",
+                            "pos": 93,
+                            "end": 97,
+                            "text": "name"
+                        },
+                        "name": {
+                            "kind": "Identifier",
+                            "pos": 93,
+                            "end": 97,
+                            "text": "name"
                         }
                     }
                 ]
diff --git a/tests/baselines/reference/checkJsdocTypedefInParamTag1.js b/tests/baselines/reference/checkJsdocTypedefInParamTag1.js
index d4983bfd581..8ef81a71cb8 100644
--- a/tests/baselines/reference/checkJsdocTypedefInParamTag1.js
+++ b/tests/baselines/reference/checkJsdocTypedefInParamTag1.js
@@ -11,7 +11,18 @@
  */
 function foo(opts) {}
 
-foo({x: 'abc'});
+foo({x: 'abc'});
+
+/**
+ * @typedef {Object} AnotherOpts
+ * @property anotherX {string}
+ * @property anotherY {string=}
+ * 
+ * @param {AnotherOpts} opts
+ */
+function foo1(opts) {}
+
+foo1({anotherX: "world"});
 
 //// [0.js]
 // @ts-check
@@ -26,3 +37,12 @@ foo({x: 'abc'});
  */
 function foo(opts) { }
 foo({ x: 'abc' });
+/**
+ * @typedef {Object} AnotherOpts
+ * @property anotherX {string}
+ * @property anotherY {string=}
+ *
+ * @param {AnotherOpts} opts
+ */
+function foo1(opts) { }
+foo1({ anotherX: "world" });
diff --git a/tests/baselines/reference/checkJsdocTypedefInParamTag1.symbols b/tests/baselines/reference/checkJsdocTypedefInParamTag1.symbols
index cd2455797b4..596e5ca89c5 100644
--- a/tests/baselines/reference/checkJsdocTypedefInParamTag1.symbols
+++ b/tests/baselines/reference/checkJsdocTypedefInParamTag1.symbols
@@ -17,3 +17,18 @@ foo({x: 'abc'});
 >foo : Symbol(foo, Decl(0.js, 0, 0))
 >x : Symbol(x, Decl(0.js, 12, 5))
 
+/**
+ * @typedef {Object} AnotherOpts
+ * @property anotherX {string}
+ * @property anotherY {string=}
+ * 
+ * @param {AnotherOpts} opts
+ */
+function foo1(opts) {}
+>foo1 : Symbol(foo1, Decl(0.js, 12, 16))
+>opts : Symbol(opts, Decl(0.js, 21, 14))
+
+foo1({anotherX: "world"});
+>foo1 : Symbol(foo1, Decl(0.js, 12, 16))
+>anotherX : Symbol(anotherX, Decl(0.js, 23, 6))
+
diff --git a/tests/baselines/reference/checkJsdocTypedefInParamTag1.types b/tests/baselines/reference/checkJsdocTypedefInParamTag1.types
index cc923e33030..82b17d71a4a 100644
--- a/tests/baselines/reference/checkJsdocTypedefInParamTag1.types
+++ b/tests/baselines/reference/checkJsdocTypedefInParamTag1.types
@@ -20,3 +20,21 @@ foo({x: 'abc'});
 >x : string
 >'abc' : "abc"
 
+/**
+ * @typedef {Object} AnotherOpts
+ * @property anotherX {string}
+ * @property anotherY {string=}
+ * 
+ * @param {AnotherOpts} opts
+ */
+function foo1(opts) {}
+>foo1 : (opts: { anotherX: string; anotherY?: string; }) => void
+>opts : { anotherX: string; anotherY?: string; }
+
+foo1({anotherX: "world"});
+>foo1({anotherX: "world"}) : void
+>foo1 : (opts: { anotherX: string; anotherY?: string; }) => void
+>{anotherX: "world"} : { anotherX: string; }
+>anotherX : string
+>"world" : "world"
+
diff --git a/tests/cases/conformance/jsdoc/checkJsdocTypedefInParamTag1.ts b/tests/cases/conformance/jsdoc/checkJsdocTypedefInParamTag1.ts
index 80ca21bd4ff..853a65766ce 100644
--- a/tests/cases/conformance/jsdoc/checkJsdocTypedefInParamTag1.ts
+++ b/tests/cases/conformance/jsdoc/checkJsdocTypedefInParamTag1.ts
@@ -14,4 +14,15 @@
  */
 function foo(opts) {}
 
-foo({x: 'abc'});
\ No newline at end of file
+foo({x: 'abc'});
+
+/**
+ * @typedef {Object} AnotherOpts
+ * @property anotherX {string}
+ * @property anotherY {string=}
+ * 
+ * @param {AnotherOpts} opts
+ */
+function foo1(opts) {}
+
+foo1({anotherX: "world"});
\ No newline at end of file

From 4838eff2d7b0833c62b6e9e667fd3d5e006cf070 Mon Sep 17 00:00:00 2001
From: Yui T <yuisu@microsoft.com>
Date: Mon, 29 May 2017 20:37:01 -0700
Subject: [PATCH 47/56] "function" without followed by "(" should be considered
 as Global function type

---
 src/compiler/checker.ts | 1 +
 src/compiler/parser.ts  | 5 ++++-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 125e492cc39..9ff1c4b41b9 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -6855,6 +6855,7 @@ namespace ts {
                     case "Object":
                         return anyType;
                     case "Function":
+                    case "function":
                         return globalFunctionType;
                     case "Array":
                     case "array":
diff --git a/src/compiler/parser.ts b/src/compiler/parser.ts
index 07d4a9ada41..04d70639e12 100644
--- a/src/compiler/parser.ts
+++ b/src/compiler/parser.ts
@@ -6075,7 +6075,10 @@ namespace ts {
                     case SyntaxKind.OpenBraceToken:
                         return parseJSDocRecordType();
                     case SyntaxKind.FunctionKeyword:
-                        return parseJSDocFunctionType();
+                        if (lookAhead(nextTokenIsOpenParen)) {
+                            return parseJSDocFunctionType();
+                        }
+                        break;
                     case SyntaxKind.DotDotDotToken:
                         return parseJSDocVariadicType();
                     case SyntaxKind.NewKeyword:

From 0ead501c86203d3c5473acaaf98e1c61ad0c5bab Mon Sep 17 00:00:00 2001
From: Yui T <yuisu@microsoft.com>
Date: Mon, 29 May 2017 20:37:15 -0700
Subject: [PATCH 48/56] Update tests and baselines

---
 tests/baselines/reference/jsDocTypeTag2.js    | 24 ++----------------
 tests/baselines/reference/jsDocTypes2.js      |  7 ++++++
 tests/baselines/reference/jsDocTypes2.symbols | 25 +++++++++++++------
 tests/baselines/reference/jsDocTypes2.types   | 14 +++++++++++
 tests/cases/conformance/salsa/jsDocTypes2.ts  |  4 +++
 5 files changed, 44 insertions(+), 30 deletions(-)

diff --git a/tests/baselines/reference/jsDocTypeTag2.js b/tests/baselines/reference/jsDocTypeTag2.js
index 07535dcee08..d54b4557f06 100644
--- a/tests/baselines/reference/jsDocTypeTag2.js
+++ b/tests/baselines/reference/jsDocTypeTag2.js
@@ -431,28 +431,8 @@
           "kind": "space"
         },
         {
-          "text": "(",
-          "kind": "punctuation"
-        },
-        {
-          "text": ")",
-          "kind": "punctuation"
-        },
-        {
-          "text": " ",
-          "kind": "space"
-        },
-        {
-          "text": "=>",
-          "kind": "punctuation"
-        },
-        {
-          "text": " ",
-          "kind": "space"
-        },
-        {
-          "text": "any",
-          "kind": "keyword"
+          "text": "Function",
+          "kind": "localName"
         }
       ],
       "documentation": [],
diff --git a/tests/baselines/reference/jsDocTypes2.js b/tests/baselines/reference/jsDocTypes2.js
index a3848704fad..ba59043978c 100644
--- a/tests/baselines/reference/jsDocTypes2.js
+++ b/tests/baselines/reference/jsDocTypes2.js
@@ -11,6 +11,10 @@ anyT1 = "hi";
 const x = (a) => a + 1;
 x(1);
 
+/** @type {function} */
+const y = (a) => a + 1;
+x(1);
+
 /** @type {function (number)} */
 const x1 = (a) => a + 1;
 x1(0);
@@ -29,6 +33,9 @@ anyT1 = "hi";
 /** @type {Function} */
 var x = function (a) { return a + 1; };
 x(1);
+/** @type {function} */
+var y = function (a) { return a + 1; };
+x(1);
 /** @type {function (number)} */
 var x1 = function (a) { return a + 1; };
 x1(0);
diff --git a/tests/baselines/reference/jsDocTypes2.symbols b/tests/baselines/reference/jsDocTypes2.symbols
index 96b32b9ad91..8f4dc4e7b43 100644
--- a/tests/baselines/reference/jsDocTypes2.symbols
+++ b/tests/baselines/reference/jsDocTypes2.symbols
@@ -20,21 +20,30 @@ const x = (a) => a + 1;
 x(1);
 >x : Symbol(x, Decl(0.js, 9, 5))
 
+/** @type {function} */
+const y = (a) => a + 1;
+>y : Symbol(y, Decl(0.js, 13, 5))
+>a : Symbol(a, Decl(0.js, 13, 11))
+>a : Symbol(a, Decl(0.js, 13, 11))
+
+x(1);
+>x : Symbol(x, Decl(0.js, 9, 5))
+
 /** @type {function (number)} */
 const x1 = (a) => a + 1;
->x1 : Symbol(x1, Decl(0.js, 13, 5))
->a : Symbol(a, Decl(0.js, 13, 12))
->a : Symbol(a, Decl(0.js, 13, 12))
+>x1 : Symbol(x1, Decl(0.js, 17, 5))
+>a : Symbol(a, Decl(0.js, 17, 12))
+>a : Symbol(a, Decl(0.js, 17, 12))
 
 x1(0);
->x1 : Symbol(x1, Decl(0.js, 13, 5))
+>x1 : Symbol(x1, Decl(0.js, 17, 5))
 
 /** @type {function (number): number} */
 const x2 = (a) => a + 1;
->x2 : Symbol(x2, Decl(0.js, 17, 5))
->a : Symbol(a, Decl(0.js, 17, 12))
->a : Symbol(a, Decl(0.js, 17, 12))
+>x2 : Symbol(x2, Decl(0.js, 21, 5))
+>a : Symbol(a, Decl(0.js, 21, 12))
+>a : Symbol(a, Decl(0.js, 21, 12))
 
 x2(0);
->x2 : Symbol(x2, Decl(0.js, 17, 5))
+>x2 : Symbol(x2, Decl(0.js, 21, 5))
 
diff --git a/tests/baselines/reference/jsDocTypes2.types b/tests/baselines/reference/jsDocTypes2.types
index db5a5902d10..599c19c7ffc 100644
--- a/tests/baselines/reference/jsDocTypes2.types
+++ b/tests/baselines/reference/jsDocTypes2.types
@@ -29,6 +29,20 @@ x(1);
 >x : Function
 >1 : 1
 
+/** @type {function} */
+const y = (a) => a + 1;
+>y : Function
+>(a) => a + 1 : (a: any) => any
+>a : any
+>a + 1 : any
+>a : any
+>1 : 1
+
+x(1);
+>x(1) : any
+>x : Function
+>1 : 1
+
 /** @type {function (number)} */
 const x1 = (a) => a + 1;
 >x1 : (arg0: number) => any
diff --git a/tests/cases/conformance/salsa/jsDocTypes2.ts b/tests/cases/conformance/salsa/jsDocTypes2.ts
index 612804b91d7..21107f87ccf 100644
--- a/tests/cases/conformance/salsa/jsDocTypes2.ts
+++ b/tests/cases/conformance/salsa/jsDocTypes2.ts
@@ -14,6 +14,10 @@ anyT1 = "hi";
 const x = (a) => a + 1;
 x(1);
 
+/** @type {function} */
+const y = (a) => a + 1;
+x(1);
+
 /** @type {function (number)} */
 const x1 = (a) => a + 1;
 x1(0);

From 10eae61aca469a590b80260e894b1816721cf9f4 Mon Sep 17 00:00:00 2001
From: Yui T <yuisu@microsoft.com>
Date: Mon, 29 May 2017 21:47:39 -0700
Subject: [PATCH 49/56] Handle "object" as "Object" in JSDoc type expression

---
 src/compiler/parser.ts | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/src/compiler/parser.ts b/src/compiler/parser.ts
index 07d4a9ada41..2d44f2eed7c 100644
--- a/src/compiler/parser.ts
+++ b/src/compiler/parser.ts
@@ -6091,7 +6091,6 @@ namespace ts {
                     case SyntaxKind.NullKeyword:
                     case SyntaxKind.UndefinedKeyword:
                     case SyntaxKind.NeverKeyword:
-                    case SyntaxKind.ObjectKeyword:
                         return parseTokenNode<JSDocType>();
                     case SyntaxKind.StringLiteral:
                     case SyntaxKind.NumericLiteral:
@@ -6769,7 +6768,7 @@ namespace ts {
                             const jsDocTypeReference = <JSDocTypeReference>typeExpression.type;
                             if (jsDocTypeReference.name.kind === SyntaxKind.Identifier) {
                                 const name = <Identifier>jsDocTypeReference.name;
-                                if (name.text === "Object") {
+                                if (name.text === "Object" || name.text === "object") {
                                     typedefTag.jsDocTypeLiteral = scanChildTags();
                                 }
                             }

From 5c7c113203a82c10f99834403eb166ab81a2ae4c Mon Sep 17 00:00:00 2001
From: Yui T <yuisu@microsoft.com>
Date: Mon, 29 May 2017 21:48:34 -0700
Subject: [PATCH 50/56] Update tests and baselines

---
 .../reference/checkJsdocTypedefInParamTag1.js | 38 +++++++++++++++++--
 .../checkJsdocTypedefInParamTag1.symbols      | 32 +++++++++++++++-
 .../checkJsdocTypedefInParamTag1.types        | 33 +++++++++++++++-
 .../jsdoc/checkJsdocTypedefInParamTag1.ts     | 22 +++++++++--
 4 files changed, 116 insertions(+), 9 deletions(-)

diff --git a/tests/baselines/reference/checkJsdocTypedefInParamTag1.js b/tests/baselines/reference/checkJsdocTypedefInParamTag1.js
index d4983bfd581..7ce5cdd6f38 100644
--- a/tests/baselines/reference/checkJsdocTypedefInParamTag1.js
+++ b/tests/baselines/reference/checkJsdocTypedefInParamTag1.js
@@ -9,9 +9,26 @@
  * 
  * @param {Opts} opts
  */
-function foo(opts) {}
+function foo(opts) {
+    opts.x;
+}
 
-foo({x: 'abc'});
+foo({x: 'abc'});
+
+/**
+ * @typedef {object} Opts1
+ * @property {string} x
+ * @property {string=} y
+ * @property {string} [z]
+ * @property {string} [w="hi"]
+ * 
+ * @param {Opts1} opts
+ */
+function foo1(opts) {
+    opts.x;
+}
+foo1({x: 'abc'});
+
 
 //// [0.js]
 // @ts-check
@@ -24,5 +41,20 @@ foo({x: 'abc'});
  *
  * @param {Opts} opts
  */
-function foo(opts) { }
+function foo(opts) {
+    opts.x;
+}
 foo({ x: 'abc' });
+/**
+ * @typedef {object} Opts1
+ * @property {string} x
+ * @property {string=} y
+ * @property {string} [z]
+ * @property {string} [w="hi"]
+ *
+ * @param {Opts1} opts
+ */
+function foo1(opts) {
+    opts.x;
+}
+foo1({ x: 'abc' });
diff --git a/tests/baselines/reference/checkJsdocTypedefInParamTag1.symbols b/tests/baselines/reference/checkJsdocTypedefInParamTag1.symbols
index cd2455797b4..be4c40643d0 100644
--- a/tests/baselines/reference/checkJsdocTypedefInParamTag1.symbols
+++ b/tests/baselines/reference/checkJsdocTypedefInParamTag1.symbols
@@ -9,11 +9,39 @@
  * 
  * @param {Opts} opts
  */
-function foo(opts) {}
+function foo(opts) {
 >foo : Symbol(foo, Decl(0.js, 0, 0))
 >opts : Symbol(opts, Decl(0.js, 10, 13))
 
+    opts.x;
+>opts.x : Symbol(x, Decl(0.js, 3, 3))
+>opts : Symbol(opts, Decl(0.js, 10, 13))
+>x : Symbol(x, Decl(0.js, 3, 3))
+}
+
 foo({x: 'abc'});
 >foo : Symbol(foo, Decl(0.js, 0, 0))
->x : Symbol(x, Decl(0.js, 12, 5))
+>x : Symbol(x, Decl(0.js, 14, 5))
+
+/**
+ * @typedef {object} Opts1
+ * @property {string} x
+ * @property {string=} y
+ * @property {string} [z]
+ * @property {string} [w="hi"]
+ * 
+ * @param {Opts1} opts
+ */
+function foo1(opts) {
+>foo1 : Symbol(foo1, Decl(0.js, 14, 16))
+>opts : Symbol(opts, Decl(0.js, 25, 14))
+
+    opts.x;
+>opts.x : Symbol(x, Decl(0.js, 18, 3))
+>opts : Symbol(opts, Decl(0.js, 25, 14))
+>x : Symbol(x, Decl(0.js, 18, 3))
+}
+foo1({x: 'abc'});
+>foo1 : Symbol(foo1, Decl(0.js, 14, 16))
+>x : Symbol(x, Decl(0.js, 28, 6))
 
diff --git a/tests/baselines/reference/checkJsdocTypedefInParamTag1.types b/tests/baselines/reference/checkJsdocTypedefInParamTag1.types
index cc923e33030..a82b125a2ba 100644
--- a/tests/baselines/reference/checkJsdocTypedefInParamTag1.types
+++ b/tests/baselines/reference/checkJsdocTypedefInParamTag1.types
@@ -9,10 +9,16 @@
  * 
  * @param {Opts} opts
  */
-function foo(opts) {}
+function foo(opts) {
 >foo : (opts: { x: string; y?: string; z?: string; w?: string; }) => void
 >opts : { x: string; y?: string; z?: string; w?: string; }
 
+    opts.x;
+>opts.x : string
+>opts : { x: string; y?: string; z?: string; w?: string; }
+>x : string
+}
+
 foo({x: 'abc'});
 >foo({x: 'abc'}) : void
 >foo : (opts: { x: string; y?: string; z?: string; w?: string; }) => void
@@ -20,3 +26,28 @@ foo({x: 'abc'});
 >x : string
 >'abc' : "abc"
 
+/**
+ * @typedef {object} Opts1
+ * @property {string} x
+ * @property {string=} y
+ * @property {string} [z]
+ * @property {string} [w="hi"]
+ * 
+ * @param {Opts1} opts
+ */
+function foo1(opts) {
+>foo1 : (opts: { x: string; y?: string; z?: string; w?: string; }) => void
+>opts : { x: string; y?: string; z?: string; w?: string; }
+
+    opts.x;
+>opts.x : string
+>opts : { x: string; y?: string; z?: string; w?: string; }
+>x : string
+}
+foo1({x: 'abc'});
+>foo1({x: 'abc'}) : void
+>foo1 : (opts: { x: string; y?: string; z?: string; w?: string; }) => void
+>{x: 'abc'} : { x: string; }
+>x : string
+>'abc' : "abc"
+
diff --git a/tests/cases/conformance/jsdoc/checkJsdocTypedefInParamTag1.ts b/tests/cases/conformance/jsdoc/checkJsdocTypedefInParamTag1.ts
index 80ca21bd4ff..fa885b9f316 100644
--- a/tests/cases/conformance/jsdoc/checkJsdocTypedefInParamTag1.ts
+++ b/tests/cases/conformance/jsdoc/checkJsdocTypedefInParamTag1.ts
@@ -9,9 +9,25 @@
  * @property {string=} y
  * @property {string} [z]
  * @property {string} [w="hi"]
- * 
+ *
  * @param {Opts} opts
  */
-function foo(opts) {}
+function foo(opts) {
+    opts.x;
+}
 
-foo({x: 'abc'});
\ No newline at end of file
+foo({x: 'abc'});
+
+/**
+ * @typedef {object} Opts1
+ * @property {string} x
+ * @property {string=} y
+ * @property {string} [z]
+ * @property {string} [w="hi"]
+ *
+ * @param {Opts1} opts
+ */
+function foo1(opts) {
+    opts.x;
+}
+foo1({x: 'abc'});

From d35e538123ecfd6cde1fe3b4872d8fe6a47c73dd Mon Sep 17 00:00:00 2001
From: Yui T <yuisu@microsoft.com>
Date: Mon, 29 May 2017 21:48:43 -0700
Subject: [PATCH 51/56] Add fourslash tests

---
 tests/baselines/reference/jsDocTypedef1.js    | 234 ++++++++++++++++++
 .../cases/fourslash/jsDocTypedefQuickInfo1.ts |  33 +++
 2 files changed, 267 insertions(+)
 create mode 100644 tests/baselines/reference/jsDocTypedef1.js
 create mode 100644 tests/cases/fourslash/jsDocTypedefQuickInfo1.ts

diff --git a/tests/baselines/reference/jsDocTypedef1.js b/tests/baselines/reference/jsDocTypedef1.js
new file mode 100644
index 00000000000..28410ee8795
--- /dev/null
+++ b/tests/baselines/reference/jsDocTypedef1.js
@@ -0,0 +1,234 @@
+[
+  {
+    "marker": {
+      "fileName": "/tests/cases/fourslash/jsDocTypedef1.js",
+      "position": 189
+    },
+    "quickInfo": {
+      "kind": "parameter",
+      "kindModifiers": "",
+      "textSpan": {
+        "start": 189,
+        "length": 4
+      },
+      "displayParts": [
+        {
+          "text": "(",
+          "kind": "punctuation"
+        },
+        {
+          "text": "parameter",
+          "kind": "text"
+        },
+        {
+          "text": ")",
+          "kind": "punctuation"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "opts",
+          "kind": "parameterName"
+        },
+        {
+          "text": ":",
+          "kind": "punctuation"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "{",
+          "kind": "punctuation"
+        },
+        {
+          "text": "\n",
+          "kind": "lineBreak"
+        },
+        {
+          "text": "    ",
+          "kind": "space"
+        },
+        {
+          "text": "x",
+          "kind": "propertyName"
+        },
+        {
+          "text": ":",
+          "kind": "punctuation"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "string",
+          "kind": "keyword"
+        },
+        {
+          "text": ";",
+          "kind": "punctuation"
+        },
+        {
+          "text": "\n",
+          "kind": "lineBreak"
+        },
+        {
+          "text": "    ",
+          "kind": "space"
+        },
+        {
+          "text": "y",
+          "kind": "propertyName"
+        },
+        {
+          "text": "?",
+          "kind": "punctuation"
+        },
+        {
+          "text": ":",
+          "kind": "punctuation"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "string",
+          "kind": "keyword"
+        },
+        {
+          "text": ";",
+          "kind": "punctuation"
+        },
+        {
+          "text": "\n",
+          "kind": "lineBreak"
+        },
+        {
+          "text": "    ",
+          "kind": "space"
+        },
+        {
+          "text": "z",
+          "kind": "propertyName"
+        },
+        {
+          "text": "?",
+          "kind": "punctuation"
+        },
+        {
+          "text": ":",
+          "kind": "punctuation"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "string",
+          "kind": "keyword"
+        },
+        {
+          "text": ";",
+          "kind": "punctuation"
+        },
+        {
+          "text": "\n",
+          "kind": "lineBreak"
+        },
+        {
+          "text": "    ",
+          "kind": "space"
+        },
+        {
+          "text": "w",
+          "kind": "propertyName"
+        },
+        {
+          "text": "?",
+          "kind": "punctuation"
+        },
+        {
+          "text": ":",
+          "kind": "punctuation"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "string",
+          "kind": "keyword"
+        },
+        {
+          "text": ";",
+          "kind": "punctuation"
+        },
+        {
+          "text": "\n",
+          "kind": "lineBreak"
+        },
+        {
+          "text": "}",
+          "kind": "punctuation"
+        }
+      ],
+      "documentation": [],
+      "tags": []
+    }
+  },
+  {
+    "marker": {
+      "fileName": "/tests/cases/fourslash/jsDocTypedef1.js",
+      "position": 424
+    },
+    "quickInfo": {
+      "kind": "parameter",
+      "kindModifiers": "",
+      "textSpan": {
+        "start": 424,
+        "length": 5
+      },
+      "displayParts": [
+        {
+          "text": "(",
+          "kind": "punctuation"
+        },
+        {
+          "text": "parameter",
+          "kind": "text"
+        },
+        {
+          "text": ")",
+          "kind": "punctuation"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "opts1",
+          "kind": "parameterName"
+        },
+        {
+          "text": ":",
+          "kind": "punctuation"
+        },
+        {
+          "text": " ",
+          "kind": "space"
+        },
+        {
+          "text": "any",
+          "kind": "keyword"
+        }
+      ],
+      "documentation": [],
+      "tags": []
+    }
+  }
+]
\ No newline at end of file
diff --git a/tests/cases/fourslash/jsDocTypedefQuickInfo1.ts b/tests/cases/fourslash/jsDocTypedefQuickInfo1.ts
new file mode 100644
index 00000000000..eea17f182e9
--- /dev/null
+++ b/tests/cases/fourslash/jsDocTypedefQuickInfo1.ts
@@ -0,0 +1,33 @@
+/// <reference path="fourslash.ts" />
+// @allowJs: true
+// @Filename: jsDocTypedef1.js
+//// /**
+////  * @typedef {Object} Opts
+////  * @property {string} x
+////  * @property {string=} y
+////  * @property {string} [z]
+////  * @property {string} [w="hi"]
+////  * 
+////  * @param {Opts} opts
+////  */
+//// function foo(/*1*/opts) {
+////     opts.x;
+///// }
+
+//// foo({x: 'abc'});
+
+//// /**
+////  * @typedef {object} Opts1
+////  * @property {string} x
+////  * @property {string=} y
+////  * @property {string} [z]
+////  * @property {string} [w="hi"]
+////  * 
+////  * @param {Opts1} opts
+////  */
+//// function foo1(/*2*/opts1) {
+////     opts1.x;
+//// }
+//// foo1({x: 'abc'});
+
+verify.baselineQuickInfo();
\ No newline at end of file

From 1e8edcbad44223d2b11f72e3eace211c12f32ff2 Mon Sep 17 00:00:00 2001
From: Yui T <yuisu@microsoft.com>
Date: Mon, 29 May 2017 21:55:55 -0700
Subject: [PATCH 52/56] remove whitespace

---
 tests/baselines/reference/checkJsdocTypedefInParamTag1.js     | 4 ++--
 .../baselines/reference/checkJsdocTypedefInParamTag1.symbols  | 4 ++--
 tests/baselines/reference/checkJsdocTypedefInParamTag1.types  | 4 ++--
 3 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/tests/baselines/reference/checkJsdocTypedefInParamTag1.js b/tests/baselines/reference/checkJsdocTypedefInParamTag1.js
index 7ce5cdd6f38..cc2e302ffca 100644
--- a/tests/baselines/reference/checkJsdocTypedefInParamTag1.js
+++ b/tests/baselines/reference/checkJsdocTypedefInParamTag1.js
@@ -6,7 +6,7 @@
  * @property {string=} y
  * @property {string} [z]
  * @property {string} [w="hi"]
- * 
+ *
  * @param {Opts} opts
  */
 function foo(opts) {
@@ -21,7 +21,7 @@ foo({x: 'abc'});
  * @property {string=} y
  * @property {string} [z]
  * @property {string} [w="hi"]
- * 
+ *
  * @param {Opts1} opts
  */
 function foo1(opts) {
diff --git a/tests/baselines/reference/checkJsdocTypedefInParamTag1.symbols b/tests/baselines/reference/checkJsdocTypedefInParamTag1.symbols
index be4c40643d0..844c4c045aa 100644
--- a/tests/baselines/reference/checkJsdocTypedefInParamTag1.symbols
+++ b/tests/baselines/reference/checkJsdocTypedefInParamTag1.symbols
@@ -6,7 +6,7 @@
  * @property {string=} y
  * @property {string} [z]
  * @property {string} [w="hi"]
- * 
+ *
  * @param {Opts} opts
  */
 function foo(opts) {
@@ -29,7 +29,7 @@ foo({x: 'abc'});
  * @property {string=} y
  * @property {string} [z]
  * @property {string} [w="hi"]
- * 
+ *
  * @param {Opts1} opts
  */
 function foo1(opts) {
diff --git a/tests/baselines/reference/checkJsdocTypedefInParamTag1.types b/tests/baselines/reference/checkJsdocTypedefInParamTag1.types
index a82b125a2ba..cb21ea2ef06 100644
--- a/tests/baselines/reference/checkJsdocTypedefInParamTag1.types
+++ b/tests/baselines/reference/checkJsdocTypedefInParamTag1.types
@@ -6,7 +6,7 @@
  * @property {string=} y
  * @property {string} [z]
  * @property {string} [w="hi"]
- * 
+ *
  * @param {Opts} opts
  */
 function foo(opts) {
@@ -32,7 +32,7 @@ foo({x: 'abc'});
  * @property {string=} y
  * @property {string} [z]
  * @property {string} [w="hi"]
- * 
+ *
  * @param {Opts1} opts
  */
 function foo1(opts) {

From e3e81b867303ce50399ae593ee6a27afbb0f1b1a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kate=20Mih=C3=A1likov=C3=A1?= <kate@katemihalikova.cz>
Date: Mon, 29 May 2017 13:40:41 +0200
Subject: [PATCH 53/56] Add support for diff3-style conflict

---
 src/compiler/scanner.ts    | 22 +++++++++++++++++-----
 src/services/classifier.ts | 10 +++++-----
 2 files changed, 22 insertions(+), 10 deletions(-)

diff --git a/src/compiler/scanner.ts b/src/compiler/scanner.ts
index d27bbf879fe..0a072a3b8ac 100644
--- a/src/compiler/scanner.ts
+++ b/src/compiler/scanner.ts
@@ -429,6 +429,7 @@ namespace ts {
               case CharacterCodes.slash:
                   // starts of normal trivia
               case CharacterCodes.lessThan:
+              case CharacterCodes.bar:
               case CharacterCodes.equals:
               case CharacterCodes.greaterThan:
                   // Starts of conflict marker trivia
@@ -496,6 +497,7 @@ namespace ts {
                       break;
 
                   case CharacterCodes.lessThan:
+                  case CharacterCodes.bar:
                   case CharacterCodes.equals:
                   case CharacterCodes.greaterThan:
                       if (isConflictMarkerTrivia(text, pos)) {
@@ -562,12 +564,12 @@ namespace ts {
             }
         }
         else {
-            Debug.assert(ch === CharacterCodes.equals);
-            // Consume everything from the start of the mid-conflict marker to the start of the next
-            // end-conflict marker.
+            Debug.assert(ch === CharacterCodes.bar || ch === CharacterCodes.equals);
+            // Consume everything from the start of a ||||||| or ======= marker to the start
+            // of the next ======= or >>>>>>> marker.
             while (pos < len) {
-                const ch = text.charCodeAt(pos);
-                if (ch === CharacterCodes.greaterThan && isConflictMarkerTrivia(text, pos)) {
+                const currentChar = text.charCodeAt(pos);
+                if ((currentChar === CharacterCodes.equals || currentChar === CharacterCodes.greaterThan) && currentChar !== ch && isConflictMarkerTrivia(text, pos)) {
                     break;
                 }
 
@@ -1562,6 +1564,16 @@ namespace ts {
                         pos++;
                         return token = SyntaxKind.OpenBraceToken;
                     case CharacterCodes.bar:
+                        if (isConflictMarkerTrivia(text, pos)) {
+                            pos = scanConflictMarkerTrivia(text, pos, error);
+                            if (skipTrivia) {
+                                continue;
+                            }
+                            else {
+                                return token = SyntaxKind.ConflictMarkerTrivia;
+                            }
+                        }
+
                         if (text.charCodeAt(pos + 1) === CharacterCodes.bar) {
                             return pos += 2, token = SyntaxKind.BarBarToken;
                         }
diff --git a/src/services/classifier.ts b/src/services/classifier.ts
index acee8fe4b0e..beeddda434e 100644
--- a/src/services/classifier.ts
+++ b/src/services/classifier.ts
@@ -685,9 +685,9 @@ namespace ts {
                         continue;
                     }
 
-                    // for the ======== add a comment for the first line, and then lex all
-                    // subsequent lines up until the end of the conflict marker.
-                    Debug.assert(ch === CharacterCodes.equals);
+                    // for the ||||||| and ======== markers, add a comment for the first line,
+                    // and then lex all subsequent lines up until the end of the conflict marker.
+                    Debug.assert(ch === CharacterCodes.bar || ch === CharacterCodes.equals);
                     classifyDisabledMergeCode(text, start, end);
                 }
             }
@@ -782,8 +782,8 @@ namespace ts {
         }
 
         function classifyDisabledMergeCode(text: string, start: number, end: number) {
-            // Classify the line that the ======= marker is on as a comment.  Then just lex
-            // all further tokens and add them to the result.
+            // Classify the line that the ||||||| or ======= marker is on as a comment.
+            // Then just lex all further tokens and add them to the result.
             let i: number;
             for (i = start; i < end; i++) {
                 if (isLineBreak(text.charCodeAt(i))) {

From 2d60b2d1175d70542acb7029a3f80faa4c3e38ba Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kate=20Mih=C3=A1likov=C3=A1?= <kate@katemihalikova.cz>
Date: Mon, 29 May 2017 13:41:28 +0200
Subject: [PATCH 54/56] Add tests and baselines

---
 .../unittests/services/colorization.ts        | 44 +++++++++++++++++++
 .../conflictMarkerDiff3Trivia1.errors.txt     | 24 ++++++++++
 .../reference/conflictMarkerDiff3Trivia1.js   | 18 ++++++++
 .../conflictMarkerDiff3Trivia2.errors.txt     | 34 ++++++++++++++
 .../reference/conflictMarkerDiff3Trivia2.js   | 28 ++++++++++++
 .../compiler/conflictMarkerDiff3Trivia1.ts    |  9 ++++
 .../compiler/conflictMarkerDiff3Trivia2.ts    | 15 +++++++
 .../fourslash/formatConflictDiff3Marker1.ts   | 22 ++++++++++
 ...ticClassificationsConflictDiff3Markers1.ts | 23 ++++++++++
 ...ticClassificationsConflictDiff3Markers2.ts | 19 ++++++++
 10 files changed, 236 insertions(+)
 create mode 100644 tests/baselines/reference/conflictMarkerDiff3Trivia1.errors.txt
 create mode 100644 tests/baselines/reference/conflictMarkerDiff3Trivia1.js
 create mode 100644 tests/baselines/reference/conflictMarkerDiff3Trivia2.errors.txt
 create mode 100644 tests/baselines/reference/conflictMarkerDiff3Trivia2.js
 create mode 100644 tests/cases/compiler/conflictMarkerDiff3Trivia1.ts
 create mode 100644 tests/cases/compiler/conflictMarkerDiff3Trivia2.ts
 create mode 100644 tests/cases/fourslash/formatConflictDiff3Marker1.ts
 create mode 100644 tests/cases/fourslash/syntacticClassificationsConflictDiff3Markers1.ts
 create mode 100644 tests/cases/fourslash/syntacticClassificationsConflictDiff3Markers2.ts

diff --git a/src/harness/unittests/services/colorization.ts b/src/harness/unittests/services/colorization.ts
index fd7d932885a..3fed9ec6164 100644
--- a/src/harness/unittests/services/colorization.ts
+++ b/src/harness/unittests/services/colorization.ts
@@ -424,6 +424,50 @@ class D { }\r\n\
                 comment("=======\r\nclass D { }\r\n"),
                 comment(">>>>>>> Branch - a"),
                 finalEndOfLineState(ts.EndOfLineState.None));
+
+            testLexicalClassification(
+"class C {\r\n\
+<<<<<<< HEAD\r\n\
+    v = 1;\r\n\
+||||||| merged common ancestors\r\n\
+    v = 3;\r\n\
+=======\r\n\
+    v = 2;\r\n\
+>>>>>>> Branch - a\r\n\
+}",
+                ts.EndOfLineState.None,
+                keyword("class"),
+                identifier("C"),
+                punctuation("{"),
+                comment("<<<<<<< HEAD"),
+                identifier("v"),
+                operator("="),
+                numberLiteral("1"),
+                punctuation(";"),
+                comment("||||||| merged common ancestors\r\n    v = 3;\r\n"),
+                comment("=======\r\n    v = 2;\r\n"),
+                comment(">>>>>>> Branch - a"),
+                punctuation("}"),
+                finalEndOfLineState(ts.EndOfLineState.None));
+
+            testLexicalClassification(
+"<<<<<<< HEAD\r\n\
+class C { }\r\n\
+||||||| merged common ancestors\r\n\
+class E { }\r\n\
+=======\r\n\
+class D { }\r\n\
+>>>>>>> Branch - a\r\n",
+                ts.EndOfLineState.None,
+                comment("<<<<<<< HEAD"),
+                keyword("class"),
+                identifier("C"),
+                punctuation("{"),
+                punctuation("}"),
+                comment("||||||| merged common ancestors\r\nclass E { }\r\n"),
+                comment("=======\r\nclass D { }\r\n"),
+                comment(">>>>>>> Branch - a"),
+                finalEndOfLineState(ts.EndOfLineState.None));
         });
 
         it("'of' keyword", function () {
diff --git a/tests/baselines/reference/conflictMarkerDiff3Trivia1.errors.txt b/tests/baselines/reference/conflictMarkerDiff3Trivia1.errors.txt
new file mode 100644
index 00000000000..b38e4e189ee
--- /dev/null
+++ b/tests/baselines/reference/conflictMarkerDiff3Trivia1.errors.txt
@@ -0,0 +1,24 @@
+tests/cases/compiler/conflictMarkerDiff3Trivia1.ts(2,1): error TS1185: Merge conflict marker encountered.
+tests/cases/compiler/conflictMarkerDiff3Trivia1.ts(4,1): error TS1185: Merge conflict marker encountered.
+tests/cases/compiler/conflictMarkerDiff3Trivia1.ts(6,1): error TS1185: Merge conflict marker encountered.
+tests/cases/compiler/conflictMarkerDiff3Trivia1.ts(8,1): error TS1185: Merge conflict marker encountered.
+
+
+==== tests/cases/compiler/conflictMarkerDiff3Trivia1.ts (4 errors) ====
+    class C {
+    <<<<<<< HEAD
+    ~~~~~~~
+!!! error TS1185: Merge conflict marker encountered.
+        v = 1;
+    ||||||| merged common ancestors
+    ~~~~~~~
+!!! error TS1185: Merge conflict marker encountered.
+        v = 3;
+    =======
+    ~~~~~~~
+!!! error TS1185: Merge conflict marker encountered.
+        v = 2;
+    >>>>>>> Branch-a
+    ~~~~~~~
+!!! error TS1185: Merge conflict marker encountered.
+    }
\ No newline at end of file
diff --git a/tests/baselines/reference/conflictMarkerDiff3Trivia1.js b/tests/baselines/reference/conflictMarkerDiff3Trivia1.js
new file mode 100644
index 00000000000..86cccd44e18
--- /dev/null
+++ b/tests/baselines/reference/conflictMarkerDiff3Trivia1.js
@@ -0,0 +1,18 @@
+//// [conflictMarkerDiff3Trivia1.ts]
+class C {
+<<<<<<< HEAD
+    v = 1;
+||||||| merged common ancestors
+    v = 3;
+=======
+    v = 2;
+>>>>>>> Branch-a
+}
+
+//// [conflictMarkerDiff3Trivia1.js]
+var C = (function () {
+    function C() {
+        this.v = 1;
+    }
+    return C;
+}());
diff --git a/tests/baselines/reference/conflictMarkerDiff3Trivia2.errors.txt b/tests/baselines/reference/conflictMarkerDiff3Trivia2.errors.txt
new file mode 100644
index 00000000000..2e29826c43a
--- /dev/null
+++ b/tests/baselines/reference/conflictMarkerDiff3Trivia2.errors.txt
@@ -0,0 +1,34 @@
+tests/cases/compiler/conflictMarkerDiff3Trivia2.ts(3,1): error TS1185: Merge conflict marker encountered.
+tests/cases/compiler/conflictMarkerDiff3Trivia2.ts(4,6): error TS2304: Cannot find name 'a'.
+tests/cases/compiler/conflictMarkerDiff3Trivia2.ts(6,1): error TS1185: Merge conflict marker encountered.
+tests/cases/compiler/conflictMarkerDiff3Trivia2.ts(9,1): error TS1185: Merge conflict marker encountered.
+tests/cases/compiler/conflictMarkerDiff3Trivia2.ts(12,1): error TS1185: Merge conflict marker encountered.
+
+
+==== tests/cases/compiler/conflictMarkerDiff3Trivia2.ts (5 errors) ====
+    class C {
+      foo() {
+    <<<<<<< B
+    ~~~~~~~
+!!! error TS1185: Merge conflict marker encountered.
+         a();
+         ~
+!!! error TS2304: Cannot find name 'a'.
+      }
+    ||||||| merged common ancestors
+    ~~~~~~~
+!!! error TS1185: Merge conflict marker encountered.
+         c();
+      }
+    =======
+    ~~~~~~~
+!!! error TS1185: Merge conflict marker encountered.
+         b();
+      }
+    >>>>>>> A
+    ~~~~~~~
+!!! error TS1185: Merge conflict marker encountered.
+    
+      public bar() { }
+    }
+    
\ No newline at end of file
diff --git a/tests/baselines/reference/conflictMarkerDiff3Trivia2.js b/tests/baselines/reference/conflictMarkerDiff3Trivia2.js
new file mode 100644
index 00000000000..61a2273019b
--- /dev/null
+++ b/tests/baselines/reference/conflictMarkerDiff3Trivia2.js
@@ -0,0 +1,28 @@
+//// [conflictMarkerDiff3Trivia2.ts]
+class C {
+  foo() {
+<<<<<<< B
+     a();
+  }
+||||||| merged common ancestors
+     c();
+  }
+=======
+     b();
+  }
+>>>>>>> A
+
+  public bar() { }
+}
+
+
+//// [conflictMarkerDiff3Trivia2.js]
+var C = (function () {
+    function C() {
+    }
+    C.prototype.foo = function () {
+        a();
+    };
+    C.prototype.bar = function () { };
+    return C;
+}());
diff --git a/tests/cases/compiler/conflictMarkerDiff3Trivia1.ts b/tests/cases/compiler/conflictMarkerDiff3Trivia1.ts
new file mode 100644
index 00000000000..072cc4b9683
--- /dev/null
+++ b/tests/cases/compiler/conflictMarkerDiff3Trivia1.ts
@@ -0,0 +1,9 @@
+class C {
+<<<<<<< HEAD
+    v = 1;
+||||||| merged common ancestors
+    v = 3;
+=======
+    v = 2;
+>>>>>>> Branch-a
+}
\ No newline at end of file
diff --git a/tests/cases/compiler/conflictMarkerDiff3Trivia2.ts b/tests/cases/compiler/conflictMarkerDiff3Trivia2.ts
new file mode 100644
index 00000000000..023d425cd4d
--- /dev/null
+++ b/tests/cases/compiler/conflictMarkerDiff3Trivia2.ts
@@ -0,0 +1,15 @@
+class C {
+  foo() {
+<<<<<<< B
+     a();
+  }
+||||||| merged common ancestors
+     c();
+  }
+=======
+     b();
+  }
+>>>>>>> A
+
+  public bar() { }
+}
diff --git a/tests/cases/fourslash/formatConflictDiff3Marker1.ts b/tests/cases/fourslash/formatConflictDiff3Marker1.ts
new file mode 100644
index 00000000000..f6492a6f60c
--- /dev/null
+++ b/tests/cases/fourslash/formatConflictDiff3Marker1.ts
@@ -0,0 +1,22 @@
+/// <reference path='fourslash.ts' />
+
+////class C {
+////<<<<<<< HEAD
+////v = 1;
+////||||||| merged common ancestors
+////v = 3;
+////=======
+////v = 2;
+////>>>>>>> Branch - a
+////}
+
+format.document();
+verify.currentFileContentIs("class C {\r\n\
+<<<<<<< HEAD\r\n\
+    v = 1;\r\n\
+||||||| merged common ancestors\r\n\
+v = 3;\r\n\
+=======\r\n\
+v = 2;\r\n\
+>>>>>>> Branch - a\r\n\
+}");
\ No newline at end of file
diff --git a/tests/cases/fourslash/syntacticClassificationsConflictDiff3Markers1.ts b/tests/cases/fourslash/syntacticClassificationsConflictDiff3Markers1.ts
new file mode 100644
index 00000000000..669705307a9
--- /dev/null
+++ b/tests/cases/fourslash/syntacticClassificationsConflictDiff3Markers1.ts
@@ -0,0 +1,23 @@
+/// <reference path="fourslash.ts"/>
+
+////class C {
+////<<<<<<< HEAD
+////    v = 1;
+////||||||| merged common ancestors
+////    v = 3;
+////=======
+////    v = 2;
+////>>>>>>> Branch - a
+////}
+
+const c = classification;
+verify.syntacticClassificationsAre(
+    c.keyword("class"), c.className("C"), c.punctuation("{"),
+    c.comment("<<<<<<< HEAD"),
+    c.identifier("v"), c.operator("="), c.numericLiteral("1"), c.punctuation(";"),
+    c.comment("||||||| merged common ancestors"),
+    c.identifier("v"), c.punctuation("="), c.numericLiteral("3"), c.punctuation(";"),
+    c.comment("======="),
+    c.identifier("v"), c.punctuation("="), c.numericLiteral("2"), c.punctuation(";"),
+    c.comment(">>>>>>> Branch - a"),
+    c.punctuation("}"));
\ No newline at end of file
diff --git a/tests/cases/fourslash/syntacticClassificationsConflictDiff3Markers2.ts b/tests/cases/fourslash/syntacticClassificationsConflictDiff3Markers2.ts
new file mode 100644
index 00000000000..17144397184
--- /dev/null
+++ b/tests/cases/fourslash/syntacticClassificationsConflictDiff3Markers2.ts
@@ -0,0 +1,19 @@
+/// <reference path="fourslash.ts"/>
+
+////<<<<<<< HEAD
+////class C { }
+////||||||| merged common ancestors
+////class E { }
+////=======
+////class D { }
+////>>>>>>> Branch - a
+
+const c = classification;
+verify.syntacticClassificationsAre(
+    c.comment("<<<<<<< HEAD"),
+    c.keyword("class"), c.className("C"), c.punctuation("{"), c.punctuation("}"),
+    c.comment("||||||| merged common ancestors"),
+    c.keyword("class"), c.identifier("E"), c.punctuation("{"), c.punctuation("}"),
+    c.comment("======="),
+    c.keyword("class"), c.identifier("D"), c.punctuation("{"), c.punctuation("}"),
+    c.comment(">>>>>>> Branch - a"));
\ No newline at end of file

From 05d3ff1823e7fe99e355de0d15517e681c37bdd7 Mon Sep 17 00:00:00 2001
From: Bill Ticehurst <billti@hotmail.com>
Date: Fri, 26 May 2017 13:56:57 -0700
Subject: [PATCH 55/56] Wrap npmLocation if needed

---
 src/server/typingsInstaller/nodeTypingsInstaller.ts | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/server/typingsInstaller/nodeTypingsInstaller.ts b/src/server/typingsInstaller/nodeTypingsInstaller.ts
index 797962cba08..6a953cd6fce 100644
--- a/src/server/typingsInstaller/nodeTypingsInstaller.ts
+++ b/src/server/typingsInstaller/nodeTypingsInstaller.ts
@@ -85,6 +85,11 @@ namespace ts.server.typingsInstaller {
                 throttleLimit,
                 log);
             this.npmPath = npmLocation !== undefined ? npmLocation : getDefaultNPMLocation(process.argv[0]);
+
+            // If the NPM path contains spaces and isn't wrapped in quotes, do so.
+            if (this.npmPath.indexOf(" ") !== -1 && this.npmPath[0] != `"`) {
+                this.npmPath = `"${this.npmPath}"`;
+            }
             if (this.log.isEnabled()) {
                 this.log.writeLine(`Process id: ${process.pid}`);
                 this.log.writeLine(`NPM location: ${this.npmPath} (explicit '${Arguments.NpmLocation}' ${npmLocation === undefined ? "not " : ""} provided)`);
@@ -186,4 +191,4 @@ namespace ts.server.typingsInstaller {
     });
     const installer = new NodeTypingsInstaller(globalTypingsCacheLocation, typingSafeListLocation, npmLocation, /*throttleLimit*/5, log);
     installer.listen();
-}
\ No newline at end of file
+}

From 2e0eb265438e6619fd6b62c52df0f47a63e17810 Mon Sep 17 00:00:00 2001
From: Bill Ticehurst <billti@hotmail.com>
Date: Fri, 26 May 2017 14:02:18 -0700
Subject: [PATCH 56/56] Fix equals

---
 src/server/typingsInstaller/nodeTypingsInstaller.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/server/typingsInstaller/nodeTypingsInstaller.ts b/src/server/typingsInstaller/nodeTypingsInstaller.ts
index 6a953cd6fce..de23b2649a6 100644
--- a/src/server/typingsInstaller/nodeTypingsInstaller.ts
+++ b/src/server/typingsInstaller/nodeTypingsInstaller.ts
@@ -87,7 +87,7 @@ namespace ts.server.typingsInstaller {
             this.npmPath = npmLocation !== undefined ? npmLocation : getDefaultNPMLocation(process.argv[0]);
 
             // If the NPM path contains spaces and isn't wrapped in quotes, do so.
-            if (this.npmPath.indexOf(" ") !== -1 && this.npmPath[0] != `"`) {
+            if (this.npmPath.indexOf(" ") !== -1 && this.npmPath[0] !== `"`) {
                 this.npmPath = `"${this.npmPath}"`;
             }
             if (this.log.isEnabled()) {