Merge branch 'master' into fix32349

src/compiler/checker.ts

@@ -42,10 +42,10 @@ namespace ts {
         iterableCacheKey: "iterationTypesOfAsyncIterable" | "iterationTypesOfIterable";
         iteratorCacheKey: "iterationTypesOfAsyncIterator" | "iterationTypesOfIterator";
         iteratorSymbolName: "asyncIterator" | "iterator";
-        getGlobalIteratorType: (reportErrors: boolean) => Type;
-        getGlobalIterableType: (reportErrors: boolean) => Type;
-        getGlobalIterableIteratorType: (reportErrors: boolean) => Type;
-        getGlobalGeneratorType: (reportErrors: boolean) => Type;
+        getGlobalIteratorType: (reportErrors: boolean) => GenericType;
+        getGlobalIterableType: (reportErrors: boolean) => GenericType;
+        getGlobalIterableIteratorType: (reportErrors: boolean) => GenericType;
+        getGlobalGeneratorType: (reportErrors: boolean) => GenericType;
         resolveIterationType: (type: Type, errorNode: Node | undefined) => Type | undefined;
         mustHaveANextMethodDiagnostic: DiagnosticMessage;
         mustBeAMethodDiagnostic: DiagnosticMessage;
@@ -9531,24 +9531,10 @@ namespace ts {
             return createTypeFromGenericGlobalType(getGlobalTypedPropertyDescriptorType(), [propertyType]);
         }
 
-        function createAsyncGeneratorType(yieldType: Type, returnType: Type, nextType: Type) {
-            const globalAsyncGeneratorType = getGlobalAsyncGeneratorType(/*reportErrors*/ true);
-            if (globalAsyncGeneratorType !== emptyGenericType) {
-                yieldType = getAwaitedType(yieldType) || unknownType;
-                returnType = getAwaitedType(returnType) || unknownType;
-                nextType = getAwaitedType(nextType) || unknownType;
-            }
-            return createTypeFromGenericGlobalType(globalAsyncGeneratorType, [yieldType, returnType, nextType]);
-        }
-
         function createIterableType(iteratedType: Type): Type {
             return createTypeFromGenericGlobalType(getGlobalIterableType(/*reportErrors*/ true), [iteratedType]);
         }
 
-        function createGeneratorType(yieldType: Type, returnType: Type, nextType: Type) {
-            return createTypeFromGenericGlobalType(getGlobalGeneratorType(/*reportErrors*/ true), [yieldType, returnType, nextType]);
-        }
-
         function createArrayType(elementType: Type, readonly?: boolean): ObjectType {
             return createTypeFromGenericGlobalType(readonly ? globalReadonlyArrayType : globalArrayType, [elementType]);
         }
@@ -9904,7 +9890,7 @@ namespace ts {
             return links.resolvedType;
         }
 
-        function addTypeToIntersection(typeSet: Type[], includes: TypeFlags, type: Type) {
+        function addTypeToIntersection(typeSet: Map<Type>, includes: TypeFlags, type: Type) {
             const flags = type.flags;
             if (flags & TypeFlags.Intersection) {
                 return addTypesToIntersection(typeSet, includes, (<IntersectionType>type).types);
@@ -9912,20 +9898,20 @@ namespace ts {
             if (isEmptyAnonymousObjectType(type)) {
                 if (!(includes & TypeFlags.IncludesEmptyObject)) {
                     includes |= TypeFlags.IncludesEmptyObject;
-                    typeSet.push(type);
+                    typeSet.set(type.id.toString(), type);
                 }
             }
             else {
                 if (flags & TypeFlags.AnyOrUnknown) {
                     if (type === wildcardType) includes |= TypeFlags.IncludesWildcard;
                 }
-                else if ((strictNullChecks || !(flags & TypeFlags.Nullable)) && !contains(typeSet, type)) {
+                else if ((strictNullChecks || !(flags & TypeFlags.Nullable)) && !typeSet.has(type.id.toString())) {
                     if (type.flags & TypeFlags.Unit && includes & TypeFlags.Unit) {
                         // We have seen two distinct unit types which means we should reduce to an
                         // empty intersection. Adding TypeFlags.NonPrimitive causes that to happen.
                         includes |= TypeFlags.NonPrimitive;
                     }
-                    typeSet.push(type);
+                    typeSet.set(type.id.toString(), type);
                 }
                 includes |= flags & TypeFlags.IncludesMask;
             }
@@ -9934,7 +9920,7 @@ namespace ts {
 
         // Add the given types to the given type set. Order is preserved, freshness is removed from literal
         // types, duplicates are removed, and nested types of the given kind are flattened into the set.
-        function addTypesToIntersection(typeSet: Type[], includes: TypeFlags, types: ReadonlyArray<Type>) {
+        function addTypesToIntersection(typeSet: Map<Type>, includes: TypeFlags, types: ReadonlyArray<Type>) {
             for (const type of types) {
                 includes = addTypeToIntersection(typeSet, includes, getRegularTypeOfLiteralType(type));
             }
@@ -10041,8 +10027,9 @@ namespace ts {
         // Also, unlike union types, the order of the constituent types is preserved in order that overload resolution
         // for intersections of types with signatures can be deterministic.
         function getIntersectionType(types: ReadonlyArray<Type>, aliasSymbol?: Symbol, aliasTypeArguments?: ReadonlyArray<Type>): Type {
-            const typeSet: Type[] = [];
-            const includes = addTypesToIntersection(typeSet, 0, types);
+            const typeMembershipMap: Map<Type> = createMap();
+            const includes = addTypesToIntersection(typeMembershipMap, 0, types);
+            const typeSet: Type[] = arrayFrom(typeMembershipMap.values());
             // An intersection type is considered empty if it contains
             // the type never, or
             // more than one unit type or,
@@ -13553,6 +13540,9 @@ namespace ts {
                     if (relation !== identityRelation) {
                         source = getApparentType(source);
                     }
+                    else if (isGenericMappedType(source)) {
+                        return Ternary.False;
+                    }
                     if (getObjectFlags(source) & ObjectFlags.Reference && getObjectFlags(target) & ObjectFlags.Reference && (<TypeReference>source).target === (<TypeReference>target).target &&
                         !(getObjectFlags(source) & ObjectFlags.MarkerType || getObjectFlags(target) & ObjectFlags.MarkerType)) {
                         // We have type references to the same generic type, and the type references are not marker
@@ -15266,8 +15256,8 @@ namespace ts {
                 const inference = inferences[i];
                 if (t === inference.typeParameter) {
                     if (fix && !inference.isFixed) {
+                        clearCachedInferences(inferences);
                         inference.isFixed = true;
-                        inference.inferredType = undefined;
                     }
                     return getInferredType(context, i);
                 }
@@ -15275,6 +15265,14 @@ namespace ts {
             return t;
         }
 
+        function clearCachedInferences(inferences: InferenceInfo[]) {
+            for (const inference of inferences) {
+                if (!inference.isFixed) {
+                    inference.inferredType = undefined;
+                }
+            }
+        }
+
         function createInferenceInfo(typeParameter: TypeParameter): InferenceInfo {
             return {
                 typeParameter,
@@ -15461,9 +15459,11 @@ namespace ts {
 
         function inferTypes(inferences: InferenceInfo[], originalSource: Type, originalTarget: Type, priority: InferencePriority = 0, contravariant = false) {
             let symbolStack: Symbol[];
-            let visited: Map<boolean>;
+            let visited: Map<number>;
             let bivariant = false;
             let propagationType: Type;
+            let inferenceCount = 0;
+            let inferenceIncomplete = false;
             let allowComplexConstraintInference = true;
             inferFromTypes(originalSource, originalTarget);
 
@@ -15505,23 +15505,28 @@ namespace ts {
                     // of all their possible values.
                     let matchingTypes: Type[] | undefined;
                     for (const t of (<UnionOrIntersectionType>source).types) {
-                        if (typeIdenticalToSomeType(t, (<UnionOrIntersectionType>target).types)) {
-                            (matchingTypes || (matchingTypes = [])).push(t);
-                            inferFromTypes(t, t);
-                        }
-                        else if (t.flags & (TypeFlags.NumberLiteral | TypeFlags.StringLiteral)) {
-                            const b = getBaseTypeOfLiteralType(t);
-                            if (typeIdenticalToSomeType(b, (<UnionOrIntersectionType>target).types)) {
-                                (matchingTypes || (matchingTypes = [])).push(t, b);
-                            }
+                        const matched = findMatchedType(t, <UnionOrIntersectionType>target);
+                        if (matched) {
+                            (matchingTypes || (matchingTypes = [])).push(matched);
+                            inferFromTypes(matched, matched);
                         }
                     }
                     // Next, to improve the quality of inferences, reduce the source and target types by
                     // removing the identically matched constituents. For example, when inferring from
                     // 'string | string[]' to 'string | T' we reduce the types to 'string[]' and 'T'.
                     if (matchingTypes) {
-                        source = removeTypesFromUnionOrIntersection(<UnionOrIntersectionType>source, matchingTypes);
-                        target = removeTypesFromUnionOrIntersection(<UnionOrIntersectionType>target, matchingTypes);
+                        const s = removeTypesFromUnionOrIntersection(<UnionOrIntersectionType>source, matchingTypes);
+                        const t = removeTypesFromUnionOrIntersection(<UnionOrIntersectionType>target, matchingTypes);
+                        if (!(s && t)) return;
+                        source = s;
+                        target = t;
+                    }
+                }
+                else if (target.flags & TypeFlags.Union && !(target.flags & TypeFlags.EnumLiteral) || target.flags & TypeFlags.Intersection) {
+                    const matched = findMatchedType(source, <UnionOrIntersectionType>target);
+                    if (matched) {
+                        inferFromTypes(matched, matched);
+                        return;
                     }
                 }
                 else if (target.flags & (TypeFlags.IndexedAccess | TypeFlags.Substitution)) {
@@ -15554,26 +15559,27 @@ namespace ts {
                                 if (contravariant && !bivariant) {
                                     if (!contains(inference.contraCandidates, candidate)) {
                                         inference.contraCandidates = append(inference.contraCandidates, candidate);
-                                        inference.inferredType = undefined;
+                                        clearCachedInferences(inferences);
                                     }
                                 }
                                 else if (!contains(inference.candidates, candidate)) {
                                     inference.candidates = append(inference.candidates, candidate);
-                                    inference.inferredType = undefined;
+                                    clearCachedInferences(inferences);
                                 }
                             }
                             if (!(priority & InferencePriority.ReturnType) && target.flags & TypeFlags.TypeParameter && inference.topLevel && !isTypeParameterAtTopLevel(originalTarget, <TypeParameter>target)) {
                                 inference.topLevel = false;
-                                inference.inferredType = undefined;
+                                clearCachedInferences(inferences);
                             }
                         }
+                        inferenceCount++;
                         return;
                     }
                     else {
                         // Infer to the simplified version of an indexed access, if possible, to (hopefully) expose more bare type parameters to the inference engine
                         const simplified = getSimplifiedType(target, /*writing*/ false);
                         if (simplified !== target) {
-                            inferFromTypesOnce(source, simplified);
+                            invokeOnce(source, simplified, inferFromTypes);
                         }
                         else if (target.flags & TypeFlags.IndexedAccess) {
                             const indexType = getSimplifiedType((target as IndexedAccessType).indexType, /*writing*/ false);
@@ -15582,13 +15588,14 @@ namespace ts {
                             if (indexType.flags & TypeFlags.Instantiable) {
                                 const simplified = distributeIndexOverObjectType(getSimplifiedType((target as IndexedAccessType).objectType, /*writing*/ false), indexType, /*writing*/ false);
                                 if (simplified && simplified !== target) {
-                                    inferFromTypesOnce(source, simplified);
+                                    invokeOnce(source, simplified, inferFromTypes);
                                 }
                             }
                         }
                     }
                 }
-                if (getObjectFlags(source) & ObjectFlags.Reference && getObjectFlags(target) & ObjectFlags.Reference && (<TypeReference>source).target === (<TypeReference>target).target) {
+                if (getObjectFlags(source) & ObjectFlags.Reference && getObjectFlags(target) & ObjectFlags.Reference && (
+                    (<TypeReference>source).target === (<TypeReference>target).target || isArrayType(source) && isArrayType(target))) {
                     // If source and target are references to the same generic type, infer from type arguments
                     inferFromTypeArguments((<TypeReference>source).typeArguments || emptyArray, (<TypeReference>target).typeArguments || emptyArray, getVariances((<TypeReference>source).target));
                 }
@@ -15618,10 +15625,10 @@ namespace ts {
                 }
                 else if (target.flags & TypeFlags.Conditional && !contravariant) {
                     const targetTypes = [getTrueTypeFromConditionalType(<ConditionalType>target), getFalseTypeFromConditionalType(<ConditionalType>target)];
-                    inferToMultipleTypes(source, targetTypes, /*isIntersection*/ false);
+                    inferToMultipleTypes(source, targetTypes, target.flags);
                 }
                 else if (target.flags & TypeFlags.UnionOrIntersection) {
-                    inferToMultipleTypes(source, (<UnionOrIntersectionType>target).types, !!(target.flags & TypeFlags.Intersection));
+                    inferToMultipleTypes(source, (<UnionOrIntersectionType>target).types, target.flags);
                 }
                 else if (source.flags & TypeFlags.Union) {
                     // Source is a union or intersection type, infer from each constituent type
@@ -15650,39 +15657,22 @@ namespace ts {
                         source = apparentSource;
                     }
                     if (source.flags & (TypeFlags.Object | TypeFlags.Intersection)) {
-                        const key = source.id + "," + target.id;
-                        if (visited && visited.get(key)) {
-                            return;
-                        }
-                        (visited || (visited = createMap<boolean>())).set(key, true);
-                        // If we are already processing another target type with the same associated symbol (such as
-                        // an instantiation of the same generic type), we do not explore this target as it would yield
-                        // no further inferences. We exclude the static side of classes from this check since it shares
-                        // its symbol with the instance side which would lead to false positives.
-                        const isNonConstructorObject = target.flags & TypeFlags.Object &&
-                            !(getObjectFlags(target) & ObjectFlags.Anonymous && target.symbol && target.symbol.flags & SymbolFlags.Class);
-                        const symbol = isNonConstructorObject ? target.symbol : undefined;
-                        if (symbol) {
-                            if (contains(symbolStack, symbol)) {
-                                return;
-                            }
-                            (symbolStack || (symbolStack = [])).push(symbol);
-                            inferFromObjectTypes(source, target);
-                            symbolStack.pop();
-                        }
-                        else {
-                            inferFromObjectTypes(source, target);
-                        }
+                        invokeOnce(source, target, inferFromObjectTypes);
                     }
                 }
+            }
 
-                function inferFromTypesOnce(source: Type, target: Type) {
-                    const key = source.id + "," + target.id;
-                    if (!visited || !visited.get(key)) {
-                        (visited || (visited = createMap<boolean>())).set(key, true);
-                        inferFromTypes(source, target);
-                    }
+            function invokeOnce(source: Type, target: Type, action: (source: Type, target: Type) => void) {
+                const key = source.id + "," + target.id;
+                const count = visited && visited.get(key);
+                if (count !== undefined) {
+                    inferenceCount += count;
+                    return;
                 }
+                (visited || (visited = createMap<number>())).set(key, 0);
+                const startCount = inferenceCount;
+                action(source, target);
+                visited.set(key, inferenceCount - startCount);
             }
 
             function inferFromTypeArguments(sourceTypes: readonly Type[], targetTypes: readonly Type[], variances: readonly VarianceFlags[]) {
@@ -15719,24 +15709,60 @@ namespace ts {
                 return undefined;
             }
 
-            function inferToMultipleTypes(source: Type, targets: Type[], isIntersection: boolean) {
-                // We infer from types that are not naked type variables first so that inferences we
-                // make from nested naked type variables and given slightly higher priority by virtue
-                // of being first in the candidates array.
+            function inferToMultipleTypes(source: Type, targets: Type[], targetFlags: TypeFlags) {
                 let typeVariableCount = 0;
-                for (const t of targets) {
-                    if (getInferenceInfoForType(t)) {
-                        typeVariableCount++;
+                if (targetFlags & TypeFlags.Union) {
+                    let nakedTypeVariable: Type | undefined;
+                    const sources = source.flags & TypeFlags.Union ? (<UnionType>source).types : [source];
+                    const matched = new Array<boolean>(sources.length);
+                    const saveInferenceIncomplete = inferenceIncomplete;
+                    inferenceIncomplete = false;
+                    // First infer to types that are not naked type variables. For each source type we
+                    // track whether inferences were made from that particular type to some target.
+                    for (const t of targets) {
+                        if (getInferenceInfoForType(t)) {
+                            nakedTypeVariable = t;
+                            typeVariableCount++;
+                        }
+                        else {
+                            for (let i = 0; i < sources.length; i++) {
+                                const count = inferenceCount;
+                                inferFromTypes(sources[i], t);
+                                if (count !== inferenceCount) matched[i] = true;
+                            }
+                        }
                     }
-                    else {
-                        inferFromTypes(source, t);
+                    const inferenceComplete = !inferenceIncomplete;
+                    inferenceIncomplete = inferenceIncomplete || saveInferenceIncomplete;
+                    // If the target has a single naked type variable and inference completed (meaning we
+                    // explored the types fully), create a union of the source types from which no inferences
+                    // have been made so far and infer from that union to the naked type variable.
+                    if (typeVariableCount === 1 && inferenceComplete) {
+                        const unmatched = flatMap(sources, (s, i) => matched[i] ? undefined : s);
+                        if (unmatched.length) {
+                            inferFromTypes(getUnionType(unmatched), nakedTypeVariable!);
+                            return;
+                        }
+                    }
+                }
+                else {
+                    // We infer from types that are not naked type variables first so that inferences we
+                    // make from nested naked type variables and given slightly higher priority by virtue
+                    // of being first in the candidates array.
+                    for (const t of targets) {
+                        if (getInferenceInfoForType(t)) {
+                            typeVariableCount++;
+                        }
+                        else {
+                            inferFromTypes(source, t);
+                        }
                     }
                 }
                 // Inferences directly to naked type variables are given lower priority as they are
                 // less specific. For example, when inferring from Promise<string> to T | Promise<T>,
                 // we want to infer string for T, not Promise<string> | string. For intersection types
                 // we only infer to single naked type variables.
-                if (isIntersection ? typeVariableCount === 1 : typeVariableCount !== 0) {
+                if (targetFlags & TypeFlags.Intersection ? typeVariableCount === 1 : typeVariableCount > 0) {
                     const savePriority = priority;
                     priority |= InferencePriority.NakedTypeVariable;
                     for (const t of targets) {
@@ -15805,6 +15831,28 @@ namespace ts {
             }
 
             function inferFromObjectTypes(source: Type, target: Type) {
+                // If we are already processing another target type with the same associated symbol (such as
+                // an instantiation of the same generic type), we do not explore this target as it would yield
+                // no further inferences. We exclude the static side of classes from this check since it shares
+                // its symbol with the instance side which would lead to false positives.
+                const isNonConstructorObject = target.flags & TypeFlags.Object &&
+                    !(getObjectFlags(target) & ObjectFlags.Anonymous && target.symbol && target.symbol.flags & SymbolFlags.Class);
+                const symbol = isNonConstructorObject ? target.symbol : undefined;
+                if (symbol) {
+                    if (contains(symbolStack, symbol)) {
+                        inferenceIncomplete = true;
+                        return;
+                    }
+                    (symbolStack || (symbolStack = [])).push(symbol);
+                    inferFromObjectTypesWorker(source, target);
+                    symbolStack.pop();
+                }
+                else {
+                    inferFromObjectTypesWorker(source, target);
+                }
+            }
+
+            function inferFromObjectTypesWorker(source: Type, target: Type) {
                 if (isGenericMappedType(source) && isGenericMappedType(target)) {
                     // The source and target types are generic types { [P in S]: X } and { [P in T]: Y }, so we infer
                     // from S to T and from X to Y.
@@ -15907,15 +15955,35 @@ namespace ts {
             }
         }
 
-        function typeIdenticalToSomeType(type: Type, types: Type[]): boolean {
+        function isMatchableType(type: Type) {
+            // We exclude non-anonymous object types because some frameworks (e.g. Ember) rely on the ability to
+            // infer between types that don't witness their type variables. Such types would otherwise be eliminated
+            // because they appear identical.
+            return !(type.flags & TypeFlags.Object) || !!(getObjectFlags(type) & ObjectFlags.Anonymous);
+        }
+
+        function typeMatchedBySomeType(type: Type, types: Type[]): boolean {
             for (const t of types) {
-                if (isTypeIdenticalTo(t, type)) {
+                if (t === type || isMatchableType(t) && isMatchableType(type) && isTypeIdenticalTo(t, type)) {
                     return true;
                 }
             }
             return false;
         }
 
+        function findMatchedType(type: Type, target: UnionOrIntersectionType) {
+            if (typeMatchedBySomeType(type, target.types)) {
+                return type;
+            }
+            if (type.flags & (TypeFlags.NumberLiteral | TypeFlags.StringLiteral) && target.flags & TypeFlags.Union) {
+                const base = getBaseTypeOfLiteralType(type);
+                if (typeMatchedBySomeType(base, target.types)) {
+                    return base;
+                }
+            }
+            return undefined;
+        }
+
         /**
          * Return a new union or intersection type computed by removing a given set of types
          * from a given union or intersection type.
@@ -15923,11 +15991,11 @@ namespace ts {
         function removeTypesFromUnionOrIntersection(type: UnionOrIntersectionType, typesToRemove: Type[]) {
             const reducedTypes: Type[] = [];
             for (const t of type.types) {
-                if (!typeIdenticalToSomeType(t, typesToRemove)) {
+                if (!typeMatchedBySomeType(t, typesToRemove)) {
                     reducedTypes.push(t);
                 }
             }
-            return type.flags & TypeFlags.Union ? getUnionType(reducedTypes) : getIntersectionType(reducedTypes);
+            return reducedTypes.length ? type.flags & TypeFlags.Union ? getUnionType(reducedTypes) : getIntersectionType(reducedTypes) : undefined;
         }
 
         function hasPrimitiveConstraint(type: TypeParameter): boolean {
@@ -20579,10 +20647,15 @@ namespace ts {
                 }
                 propType = getConstraintForLocation(getTypeOfSymbol(prop), node);
             }
+            return getFlowTypeOfAccessExpression(node, prop, propType, right);
+        }
+
+        function getFlowTypeOfAccessExpression(node: ElementAccessExpression | PropertyAccessExpression | QualifiedName, prop: Symbol | undefined, propType: Type, errorNode: Node) {
             // Only compute control flow type if this is a property access expression that isn't an
             // assignment target, and the referenced property was declared as a variable, property,
             // accessor, or optional method.
-            if (node.kind !== SyntaxKind.PropertyAccessExpression ||
+            const assignmentKind = getAssignmentTargetKind(node);
+            if (node.kind !== SyntaxKind.ElementAccessExpression && node.kind !== SyntaxKind.PropertyAccessExpression ||
                 assignmentKind === AssignmentKind.Definite ||
                 prop && !(prop.flags & (SymbolFlags.Variable | SymbolFlags.Property | SymbolFlags.Accessor)) && !(prop.flags & SymbolFlags.Method && propType.flags & TypeFlags.Union)) {
                 return propType;
@@ -20592,7 +20665,7 @@ namespace ts {
             // and if we are in a constructor of the same class as the property declaration, assume that
             // the property is uninitialized at the top of the control flow.
             let assumeUninitialized = false;
-            if (strictNullChecks && strictPropertyInitialization && left.kind === SyntaxKind.ThisKeyword) {
+            if (strictNullChecks && strictPropertyInitialization && node.expression.kind === SyntaxKind.ThisKeyword) {
                 const declaration = prop && prop.valueDeclaration;
                 if (declaration && isInstancePropertyWithoutInitializer(declaration)) {
                     const flowContainer = getControlFlowContainer(node);
@@ -20609,7 +20682,7 @@ namespace ts {
             }
             const flowType = getFlowTypeOfReference(node, propType, assumeUninitialized ? getOptionalType(propType) : propType);
             if (assumeUninitialized && !(getFalsyFlags(propType) & TypeFlags.Undefined) && getFalsyFlags(flowType) & TypeFlags.Undefined) {
-                error(right, Diagnostics.Property_0_is_used_before_being_assigned, symbolToString(prop!)); // TODO: GH#18217
+                error(errorNode, Diagnostics.Property_0_is_used_before_being_assigned, symbolToString(prop!)); // TODO: GH#18217
                 // Return the declared type to reduce follow-on errors
                 return propType;
             }
@@ -20966,7 +21039,7 @@ namespace ts {
                 AccessFlags.Writing | (isGenericObjectType(objectType) && !isThisTypeParameter(objectType) ? AccessFlags.NoIndexSignatures : 0) :
                 AccessFlags.None;
             const indexedAccessType = getIndexedAccessTypeOrUndefined(objectType, effectiveIndexType, node, accessFlags) || errorType;
-            return checkIndexedAccessIndexType(indexedAccessType, node);
+            return checkIndexedAccessIndexType(getFlowTypeOfAccessExpression(node, indexedAccessType.symbol, indexedAccessType, indexExpression), node);
         }
 
         function checkThatExpressionIsProperSymbolReference(expression: Expression, expressionType: Type, reportError: boolean): boolean {
@@ -22750,7 +22823,7 @@ namespace ts {
                  isVariableDeclaration(decl.parent) && getSymbolOfNode(decl.parent));
             const prototype = assignmentSymbol && assignmentSymbol.exports && assignmentSymbol.exports.get("prototype" as __String);
             const init = prototype && prototype.valueDeclaration && getAssignedJSPrototype(prototype.valueDeclaration);
-            return init ? checkExpression(init) : undefined;
+            return init ? getWidenedType(checkExpressionCached(init)) : undefined;
         }
 
         function getAssignedJSPrototype(node: Node) {
@@ -23393,9 +23466,36 @@ namespace ts {
         }
 
         function createGeneratorReturnType(yieldType: Type, returnType: Type, nextType: Type, isAsyncGenerator: boolean) {
-            return isAsyncGenerator
-                ? createAsyncGeneratorType(yieldType, returnType, nextType)
-                : createGeneratorType(yieldType, returnType, nextType);
+            const resolver = isAsyncGenerator ? asyncIterationTypesResolver : syncIterationTypesResolver;
+            const globalGeneratorType = resolver.getGlobalGeneratorType(/*reportErrors*/ false);
+            yieldType = resolver.resolveIterationType(yieldType, /*errorNode*/ undefined) || unknownType;
+            returnType = resolver.resolveIterationType(returnType, /*errorNode*/ undefined) || unknownType;
+            nextType = resolver.resolveIterationType(nextType, /*errorNode*/ undefined) || unknownType;
+            if (globalGeneratorType === emptyGenericType) {
+                // Fall back to the global IterableIterator if returnType is assignable to the expected return iteration
+                // type of IterableIterator, and the expected next iteration type of IterableIterator is assignable to
+                // nextType.
+                const globalType = resolver.getGlobalIterableIteratorType(/*reportErrors*/ false);
+                const iterationTypes = globalType !== emptyGenericType ? getIterationTypesOfGlobalIterableType(globalType, resolver) : undefined;
+                const iterableIteratorReturnType = iterationTypes ? iterationTypes.returnType : anyType;
+                const iterableIteratorNextType = iterationTypes ? iterationTypes.nextType : undefinedType;
+                if (isTypeAssignableTo(returnType, iterableIteratorReturnType) &&
+                    isTypeAssignableTo(iterableIteratorNextType, nextType)) {
+                    if (globalType !== emptyGenericType) {
+                        return createTypeFromGenericGlobalType(globalType, [yieldType]);
+                    }
+
+                    // The global IterableIterator type doesn't exist, so report an error
+                    resolver.getGlobalIterableIteratorType(/*reportErrors*/ true);
+                    return emptyObjectType;
+                }
+
+                // The global Generator type doesn't exist, so report an error
+                resolver.getGlobalGeneratorType(/*reportErrors*/ true);
+                return emptyObjectType;
+            }
+
+            return createTypeFromGenericGlobalType(globalGeneratorType, [yieldType, returnType, nextType]);
         }
 
         function checkAndAggregateYieldOperandTypes(func: FunctionLikeDeclaration, checkMode: CheckMode | undefined) {
@@ -24714,6 +24814,12 @@ namespace ts {
                     || anyType;
             }
 
+            const contextualReturnType = getContextualReturnType(func);
+            if (contextualReturnType) {
+                return getIterationTypeOfGeneratorFunctionReturnType(IterationTypeKind.Next, contextualReturnType, isAsync)
+                    || anyType;
+            }
+
             return anyType;
         }
 
@@ -26403,7 +26509,11 @@ namespace ts {
          * The runtime behavior of the `await` keyword.
          */
         function checkAwaitedType(type: Type, errorNode: Node, diagnosticMessage: DiagnosticMessage, arg0?: string | number): Type {
-            return getAwaitedType(type, errorNode, diagnosticMessage, arg0) || errorType;
+            const awaitedType = getAwaitedType(type, errorNode, diagnosticMessage, arg0);
+            if (awaitedType === type && !(type.flags & TypeFlags.AnyOrUnknown)) {
+                addErrorOrSuggestion(/*isError*/ false, createDiagnosticForNode(errorNode, Diagnostics.await_has_no_effect_on_the_type_of_this_expression));
+            }
+            return awaitedType || errorType;
         }
 
         function getAwaitedType(type: Type, errorNode?: Node, diagnosticMessage?: DiagnosticMessage, arg0?: string | number): Type | undefined {
@@ -28228,6 +28338,13 @@ namespace ts {
             return (type as IterableOrIteratorType)[resolver.iterableCacheKey];
         }
 
+        function getIterationTypesOfGlobalIterableType(globalType: Type, resolver: IterationTypesResolver) {
+            const globalIterationTypes =
+                getIterationTypesOfIterableCached(globalType, resolver) ||
+                getIterationTypesOfIterableSlow(globalType, resolver, /*errorNode*/ undefined);
+            return globalIterationTypes === noIterationTypes ? defaultIterationTypes : globalIterationTypes;
+        }
+
         /**
          * Gets the *yield*, *return*, and *next* types of an `Iterable`-like or `AsyncIterable`-like
          * type from from common heuristics.
@@ -28253,10 +28370,7 @@ namespace ts {
                 // iteration types of their `[Symbol.iterator]()` method. The same is true for their async cousins.
                 // While we define these as `any` and `undefined` in our libs by default, a custom lib *could* use
                 // different definitions.
-                const globalIterationTypes =
-                    getIterationTypesOfIterableCached(globalType, resolver) ||
-                    getIterationTypesOfIterableSlow(globalType, resolver, /*errorNode*/ undefined);
-                const { returnType, nextType } = globalIterationTypes === noIterationTypes ? defaultIterationTypes : globalIterationTypes;
+                const { returnType, nextType } = getIterationTypesOfGlobalIterableType(globalType, resolver);
                 return (type as IterableOrIteratorType)[resolver.iterableCacheKey] = createIterationTypes(yieldType, returnType, nextType);
             }
 
@@ -33013,9 +33127,6 @@ namespace ts {
                         return grammarErrorAtPos(node, node.end - 1, ";".length, Diagnostics._0_expected, "{");
                     }
                 }
-                else if (isClassLike(node.parent) && isStringLiteral(node.name) && node.name.text === "constructor" && (!compilerOptions.target || compilerOptions.target < ScriptTarget.ES5)) {
-                    return grammarErrorOnNode(node.name, Diagnostics.Quoted_constructors_have_previously_been_interpreted_as_methods_which_is_incorrect_In_TypeScript_3_6_they_will_be_correctly_parsed_as_constructors_In_the_meantime_consider_using_constructor_to_write_a_constructor_or_constructor_to_write_a_method);
-                }
                 if (checkGrammarForGenerator(node)) {
                     return true;
                 }

src/compiler/diagnosticMessages.json

@@ -4635,6 +4635,11 @@
         "category": "Suggestion",
         "code": 80006
     },
+    "'await' has no effect on the type of this expression.": {
+        "category": "Suggestion",
+        "code": 80007
+    },
+
     "Add missing 'super()' call": {
         "category": "Message",
         "code": 90001
@@ -5095,15 +5100,19 @@
         "category": "Message",
         "code": 95085
     },
+    "Remove unnecessary 'await'": {
+        "category": "Message",
+        "code": 95086
+    },
+    "Remove all unnecessary uses of 'await'": {
+        "category": "Message",
+        "code": 95087
+    },
 
     "No value exists in scope for the shorthand property '{0}'. Either declare one or provide an initializer.": {
         "category": "Error",
         "code": 18004
     },
-    "Quoted constructors have previously been interpreted as methods, which is incorrect. In TypeScript 3.6, they will be correctly parsed as constructors. In the meantime, consider using 'constructor()' to write a constructor, or '[\"constructor\"]()' to write a method.": {
-        "category": "Error",
-        "code": 18005
-    },
     "Classes may not have a field named 'constructor'.": {
         "category": "Error",
         "code": 18006

src/compiler/emitter.ts

@@ -411,7 +411,11 @@ namespace ts {
                     }
                 );
                 if (emitOnlyDtsFiles && declarationTransform.transformed[0].kind === SyntaxKind.SourceFile) {
-                    const sourceFile = declarationTransform.transformed[0] as SourceFile;
+                    // Improved narrowing in master/3.6 makes this cast unnecessary, triggering a lint rule.
+                    // But at the same time, the LKG (3.5) necessitates it because it doesn’t narrow.
+                    // Once the LKG is updated to 3.6, this comment, the cast to `SourceFile`, and the
+                    // tslint directive can be all be removed.
+                    const sourceFile = declarationTransform.transformed[0] as SourceFile; // tslint:disable-line
                     exportedModulesFromDeclarationEmit = sourceFile.exportedModulesFromDeclarationEmit;
                 }
             }

src/compiler/factory.ts

@@ -4701,7 +4701,7 @@ namespace ts {
         }
     }
 
-    function getLeftmostExpression(node: Expression, stopAtCallExpressions: boolean) {
+    export function getLeftmostExpression(node: Expression, stopAtCallExpressions: boolean) {
         while (true) {
             switch (node.kind) {
                 case SyntaxKind.PostfixUnaryExpression:

src/compiler/parser.ts

@@ -5656,12 +5656,27 @@ namespace ts {
             return finishNode(node);
         }
 
-        function parseConstructorDeclaration(node: ConstructorDeclaration): ConstructorDeclaration {
-            node.kind = SyntaxKind.Constructor;
-            parseExpected(SyntaxKind.ConstructorKeyword);
-            fillSignature(SyntaxKind.ColonToken, SignatureFlags.None, node);
-            node.body = parseFunctionBlockOrSemicolon(SignatureFlags.None, Diagnostics.or_expected);
-            return finishNode(node);
+        function parseConstructorName() {
+            if (token() === SyntaxKind.ConstructorKeyword) {
+                return parseExpected(SyntaxKind.ConstructorKeyword);
+            }
+            if (token() === SyntaxKind.StringLiteral && lookAhead(nextToken) === SyntaxKind.OpenParenToken) {
+                return tryParse(() => {
+                    const literalNode = parseLiteralNode();
+                    return literalNode.text === "constructor" ? literalNode : undefined;
+                });
+            }
+        }
+
+        function tryParseConstructorDeclaration(node: ConstructorDeclaration): ConstructorDeclaration | undefined {
+            return tryParse(() => {
+                if (parseConstructorName()) {
+                    node.kind = SyntaxKind.Constructor;
+                    fillSignature(SyntaxKind.ColonToken, SignatureFlags.None, node);
+                    node.body = parseFunctionBlockOrSemicolon(SignatureFlags.None, Diagnostics.or_expected);
+                    return finishNode(node);
+                }
+            });
         }
 
         function parseMethodDeclaration(node: MethodDeclaration, asteriskToken: AsteriskToken, diagnosticMessage?: DiagnosticMessage): MethodDeclaration {
@@ -5867,8 +5882,11 @@ namespace ts {
                 return parseAccessorDeclaration(<AccessorDeclaration>node, SyntaxKind.SetAccessor);
             }
 
-            if (token() === SyntaxKind.ConstructorKeyword) {
-                return parseConstructorDeclaration(<ConstructorDeclaration>node);
+            if (token() === SyntaxKind.ConstructorKeyword || token() === SyntaxKind.StringLiteral) {
+                const constructorDeclaration = tryParseConstructorDeclaration(<ConstructorDeclaration>node);
+                if (constructorDeclaration) {
+                    return constructorDeclaration;
+                }
             }
 
             if (isIndexSignature()) {

src/compiler/scanner.ts

@@ -197,6 +197,7 @@ namespace ts {
         "|=": SyntaxKind.BarEqualsToken,
         "^=": SyntaxKind.CaretEqualsToken,
         "@": SyntaxKind.AtToken,
+        "`": SyntaxKind.BacktickToken
     });
 
     /*
@@ -298,7 +299,6 @@ namespace ts {
     }
 
     const tokenStrings = makeReverseMap(textToToken);
-
     export function tokenToString(t: SyntaxKind): string | undefined {
         return tokenStrings[t];
     }

src/compiler/transformers/es2017.ts

@@ -775,10 +775,11 @@ namespace ts {
         priority: 5,
         text: `
             var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+                function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
                 return new (P || (P = Promise))(function (resolve, reject) {
                     function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
                     function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
-                    function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+                    function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
                     step((generator = generator.apply(thisArg, _arguments || [])).next());
                 });
             };`

src/compiler/transformers/es2018.ts

@@ -229,14 +229,39 @@ namespace ts {
             if (node.transformFlags & TransformFlags.ContainsObjectRestOrSpread) {
                 // spread elements emit like so:
                 // non-spread elements are chunked together into object literals, and then all are passed to __assign:
-                //     { a, ...o, b } => __assign({a}, o, {b});
+                //     { a, ...o, b } => __assign(__assign({a}, o), {b});
                 // If the first element is a spread element, then the first argument to __assign is {}:
-                //     { ...o, a, b, ...o2 } => __assign({}, o, {a, b}, o2)
+                //     { ...o, a, b, ...o2 } => __assign(__assign(__assign({}, o), {a, b}), o2)
+                //
+                // We cannot call __assign with more than two elements, since any element could cause side effects. For
+                // example:
+                //      var k = { a: 1, b: 2 };
+                //      var o = { a: 3, ...k, b: k.a++ };
+                //      // expected: { a: 1, b: 1 }
+                // If we translate the above to `__assign({ a: 3 }, k, { b: k.a++ })`, the `k.a++` will evaluate before
+                // `k` is spread and we end up with `{ a: 2, b: 1 }`.
+                //
+                // This also occurs for spread elements, not just property assignments:
+                //      var k = { a: 1, get b() { l = { z: 9 }; return 2; } };
+                //      var l = { c: 3 };
+                //      var o = { ...k, ...l };
+                //      // expected: { a: 1, b: 2, z: 9 }
+                // If we translate the above to `__assign({}, k, l)`, the `l` will evaluate before `k` is spread and we
+                // end up with `{ a: 1, b: 2, c: 3 }`
                 const objects = chunkObjectLiteralElements(node.properties);
                 if (objects.length && objects[0].kind !== SyntaxKind.ObjectLiteralExpression) {
                     objects.unshift(createObjectLiteral());
                 }
-                return createAssignHelper(context, objects);
+                let expression: Expression = objects[0];
+                if (objects.length > 1) {
+                    for (let i = 1; i < objects.length; i++) {
+                        expression = createAssignHelper(context, [expression, objects[i]]);
+                    }
+                    return expression;
+                }
+                else {
+                    return createAssignHelper(context, objects);
+                }
             }
             return visitEachChild(node, visitor, context);
         }

src/compiler/types.ts

@@ -1882,6 +1882,7 @@ namespace ts {
     }
 
     export interface JsxAttributes extends ObjectLiteralExpressionBase<JsxAttributeLike> {
+        kind: SyntaxKind.JsxAttributes;
         parent: JsxOpeningLikeElement;
     }
 
@@ -4759,7 +4760,7 @@ namespace ts {
         UMD = 3,
         System = 4,
         ES2015 = 5,
-        ESNext = 6
+        ESNext = 99
     }
 
     export const enum JsxEmit {
@@ -4807,7 +4808,7 @@ namespace ts {
         ES2018 = 5,
         ES2019 = 6,
         ES2020 = 7,
-        ESNext = 8,
+        ESNext = 99,
         JSON = 100,
         Latest = ESNext,
     }

src/compiler/utilities.ts

@@ -3150,6 +3150,23 @@ namespace ts {
         return s.replace(escapedCharsRegExp, getReplacement);
     }
 
+    /**
+     * Strip off existed single quotes or double quotes from a given string
+     *
+     * @return non-quoted string
+     */
+    export function stripQuotes(name: string) {
+        const length = name.length;
+        if (length >= 2 && name.charCodeAt(0) === name.charCodeAt(length - 1) && startsWithQuote(name)) {
+            return name.substring(1, length - 1);
+        }
+        return name;
+    }
+
+    export function startsWithQuote(name: string): boolean {
+        return isSingleOrDoubleQuote(name.charCodeAt(0));
+    }
+
     function getReplacement(c: string, offset: number, input: string) {
         if (c.charCodeAt(0) === CharacterCodes.nullCharacter) {
             const lookAhead = input.charCodeAt(offset + c.length);
@@ -7468,7 +7485,7 @@ namespace ts {
     export function getDirectoryPath(path: Path): Path;
     /**
      * Returns the path except for its basename. Semantics align with NodeJS's `path.dirname`
-     * except that we support URLs as well.
+     * except that we support URL's as well.
      *
      * ```ts
      * getDirectoryPath("/path/to/file.ext") === "/path/to"

src/harness/fourslash.ts

@@ -797,8 +797,8 @@ namespace FourSlash {
                     for (const include of toArray(options.includes)) {
                         const name = typeof include === "string" ? include : include.name;
                         const found = nameToEntries.get(name);
-                        if (!found) throw this.raiseError(`No completion ${name} found`);
-                        assert(found.length === 1, `Must use 'exact' for multiple completions with same name: '${name}'`);
+                        if (!found) throw this.raiseError(`Includes: completion '${name}' not found.`);
+                        assert(found.length === 1); // Must use 'exact' for multiple completions with same name
                         this.verifyCompletionEntry(ts.first(found), include);
                     }
                 }
@@ -806,7 +806,7 @@ namespace FourSlash {
                     for (const exclude of toArray(options.excludes)) {
                         assert(typeof exclude === "string");
                         if (nameToEntries.has(exclude)) {
-                            this.raiseError(`Did not expect to get a completion named ${exclude}`);
+                            this.raiseError(`Excludes: unexpected completion '${exclude}' found.`);
                         }
                     }
                 }
@@ -865,7 +865,7 @@ namespace FourSlash {
             ts.zipWith(actual, expected, (completion, expectedCompletion, index) => {
                 const name = typeof expectedCompletion === "string" ? expectedCompletion : expectedCompletion.name;
                 if (completion.name !== name) {
-                    this.raiseError(`${marker ? JSON.stringify(marker) : "" } Expected completion at index ${index} to be ${name}, got ${completion.name}`);
+                    this.raiseError(`${marker ? JSON.stringify(marker) : ""} Expected completion at index ${index} to be ${name}, got ${completion.name}`);
                 }
                 this.verifyCompletionEntry(completion, expectedCompletion);
             });
@@ -948,7 +948,7 @@ namespace FourSlash {
 
             const actual = checker.typeToString(type);
             if (actual !== expected) {
-                this.raiseError(`Expected: '${expected}', actual: '${actual}'`);
+                this.raiseError(displayExpectedAndActualString(expected, actual));
             }
         }
 
@@ -1024,9 +1024,7 @@ namespace FourSlash {
         private assertObjectsEqual<T>(fullActual: T, fullExpected: T, msgPrefix = ""): void {
             const recur = <U>(actual: U, expected: U, path: string) => {
                 const fail = (msg: string) => {
-                    this.raiseError(`${msgPrefix} At ${path}: ${msg}
-Expected: ${stringify(fullExpected)}
-Actual: ${stringify(fullActual)}`);
+                    this.raiseError(`${msgPrefix} At ${path}: ${msg} ${displayExpectedAndActualString(stringify(fullExpected), stringify(fullActual))}`);
                 };
 
                 if ((actual === undefined) !== (expected === undefined)) {
@@ -1058,9 +1056,7 @@ Actual: ${stringify(fullActual)}`);
                 if (fullActual === fullExpected) {
                     return;
                 }
-                this.raiseError(`${msgPrefix}
-Expected: ${stringify(fullExpected)}
-Actual: ${stringify(fullActual)}`);
+                this.raiseError(`${msgPrefix} ${displayExpectedAndActualString(stringify(fullExpected), stringify(fullActual))}`);
             }
             recur(fullActual, fullExpected, "");
 
@@ -2111,9 +2107,7 @@ Actual: ${stringify(fullActual)}`);
         public verifyCurrentLineContent(text: string) {
             const actual = this.getCurrentLineContent();
             if (actual !== text) {
-                throw new Error("verifyCurrentLineContent\n" +
-                    "\tExpected: \"" + text + "\"\n" +
-                    "\t  Actual: \"" + actual + "\"");
+                throw new Error("verifyCurrentLineContent\n" + displayExpectedAndActualString(text, actual, /* quoted */ true));
             }
         }
 
@@ -2139,25 +2133,19 @@ Actual: ${stringify(fullActual)}`);
         public verifyTextAtCaretIs(text: string) {
             const actual = this.getFileContent(this.activeFile.fileName).substring(this.currentCaretPosition, this.currentCaretPosition + text.length);
             if (actual !== text) {
-                throw new Error("verifyTextAtCaretIs\n" +
-                    "\tExpected: \"" + text + "\"\n" +
-                    "\t  Actual: \"" + actual + "\"");
+                throw new Error("verifyTextAtCaretIs\n" + displayExpectedAndActualString(text, actual, /* quoted */ true));
             }
         }
 
         public verifyCurrentNameOrDottedNameSpanText(text: string) {
             const span = this.languageService.getNameOrDottedNameSpan(this.activeFile.fileName, this.currentCaretPosition, this.currentCaretPosition);
             if (!span) {
-                return this.raiseError("verifyCurrentNameOrDottedNameSpanText\n" +
-                    "\tExpected: \"" + text + "\"\n" +
-                    "\t  Actual: undefined");
+                return this.raiseError("verifyCurrentNameOrDottedNameSpanText\n" + displayExpectedAndActualString("\"" + text + "\"", "undefined"));
             }
 
             const actual = this.getFileContent(this.activeFile.fileName).substring(span.start, ts.textSpanEnd(span));
             if (actual !== text) {
-                this.raiseError("verifyCurrentNameOrDottedNameSpanText\n" +
-                    "\tExpected: \"" + text + "\"\n" +
-                    "\t  Actual: \"" + actual + "\"");
+                this.raiseError("verifyCurrentNameOrDottedNameSpanText\n" + displayExpectedAndActualString(text, actual, /* quoted */ true));
             }
         }
 
@@ -3690,7 +3678,7 @@ ${code}
             expected = makeWhitespaceVisible(expected);
             actual = makeWhitespaceVisible(actual);
         }
-        return `Expected:\n${expected}\nActual:\n${actual}`;
+        return displayExpectedAndActualString(expected, actual);
     }
 
     function differOnlyByWhitespace(a: string, b: string) {
@@ -3710,6 +3698,14 @@ ${code}
             }
         }
     }
+
+    function displayExpectedAndActualString(expected: string, actual: string, quoted = false) {
+        const expectMsg = "\x1b[1mExpected\x1b[0m\x1b[31m";
+        const actualMsg = "\x1b[1mActual\x1b[0m\x1b[31m";
+        const expectedString = quoted ? "\"" + expected + "\"" : expected;
+        const actualString = quoted ? "\"" + actual + "\"" : actual;
+        return `\n${expectMsg}:\n${expectedString}\n\n${actualMsg}:\n${actualString}`;
+    }
 }
 
 namespace FourSlashInterface {
@@ -3759,7 +3755,7 @@ namespace FourSlashInterface {
     }
 
     export class Plugins {
-        constructor (private state: FourSlash.TestState) {
+        constructor(private state: FourSlash.TestState) {
         }
 
         public configurePlugin(pluginName: string, configuration: any): void {
@@ -4582,7 +4578,7 @@ namespace FourSlashInterface {
         export const keywords: ReadonlyArray<ExpectedCompletionEntryObject> = keywordsWithUndefined.filter(k => k.name !== "undefined");
 
         export const typeKeywords: ReadonlyArray<ExpectedCompletionEntryObject> =
-            ["false", "null", "true", "void", "any", "boolean", "keyof", "never", "number", "object", "string", "symbol", "undefined", "unique", "unknown", "bigint"].map(keywordEntry);
+            ["false", "null", "true", "void", "any", "boolean", "keyof", "never", "readonly", "number", "object", "string", "symbol", "undefined", "unique", "unknown", "bigint"].map(keywordEntry);
 
         const globalTypeDecls: ReadonlyArray<ExpectedCompletionEntryObject> = [
             interfaceEntry("Symbol"),
@@ -4698,6 +4694,9 @@ namespace FourSlashInterface {
             ];
         }
 
+        export const typeAssertionKeywords: ReadonlyArray<ExpectedCompletionEntry> =
+            globalTypesPlus([keywordEntry("const")]);
+
         function getInJsKeywords(keywords: ReadonlyArray<ExpectedCompletionEntryObject>): ReadonlyArray<ExpectedCompletionEntryObject> {
             return keywords.filter(keyword => {
                 switch (keyword.name) {
@@ -4828,40 +4827,23 @@ namespace FourSlashInterface {
             "interface",
             "let",
             "package",
-            "private",
-            "protected",
-            "public",
-            "static",
             "yield",
-            "abstract",
-            "as",
             "any",
             "async",
             "await",
             "boolean",
-            "constructor",
             "declare",
-            "get",
-            "infer",
-            "is",
             "keyof",
             "module",
-            "namespace",
             "never",
             "readonly",
-            "require",
             "number",
             "object",
-            "set",
             "string",
             "symbol",
-            "type",
             "unique",
             "unknown",
-            "from",
-            "global",
             "bigint",
-            "of",
         ].map(keywordEntry);
 
         export const statementKeywords: ReadonlyArray<ExpectedCompletionEntryObject> = statementKeywordsWithTypes.filter(k => {
@@ -5042,40 +5024,23 @@ namespace FourSlashInterface {
             "interface",
             "let",
             "package",
-            "private",
-            "protected",
-            "public",
-            "static",
             "yield",
-            "abstract",
-            "as",
             "any",
             "async",
             "await",
             "boolean",
-            "constructor",
             "declare",
-            "get",
-            "infer",
-            "is",
             "keyof",
             "module",
-            "namespace",
             "never",
             "readonly",
-            "require",
             "number",
             "object",
-            "set",
             "string",
             "symbol",
-            "type",
             "unique",
             "unknown",
-            "from",
-            "global",
             "bigint",
-            "of",
         ].map(keywordEntry);
 
         export const globalInJsKeywords = getInJsKeywords(globalKeywords);
@@ -5128,11 +5093,6 @@ namespace FourSlashInterface {
 
         export const insideMethodInJsKeywords = getInJsKeywords(insideMethodKeywords);
 
-        export const globalKeywordsPlusUndefined: ReadonlyArray<ExpectedCompletionEntryObject> = (() => {
-            const i = ts.findIndex(globalKeywords, x => x.name === "unique");
-            return [...globalKeywords.slice(0, i), keywordEntry("undefined"), ...globalKeywords.slice(i)];
-        })();
-
         export const globals: ReadonlyArray<ExpectedCompletionEntryObject> = [
             globalThisEntry,
             ...globalsVars,

src/harness/virtualFileSystemWithWatch.ts

@@ -30,7 +30,7 @@ interface Array<T> {}`
         return combinePaths(getDirectoryPath(libFile.path), "tsc.js");
     }
 
-    interface TestServerHostCreationParameters {
+    export interface TestServerHostCreationParameters {
         useCaseSensitiveFileNames?: boolean;
         executingFilePath?: string;
         currentDirectory?: string;

src/jsTyping/jsTyping.ts

@@ -289,9 +289,8 @@ namespace ts.JsTyping {
 
     }
 
-    export const enum PackageNameValidationResult {
+    export const enum NameValidationResult {
         Ok,
-        ScopedPackagesNotSupported,
         EmptyName,
         NameTooLong,
         NameStartsWithDot,
@@ -301,49 +300,77 @@ namespace ts.JsTyping {
 
     const maxPackageNameLength = 214;
 
+    export interface ScopedPackageNameValidationResult {
+        name: string;
+        isScopeName: boolean;
+        result: NameValidationResult;
+    }
+    export type PackageNameValidationResult = NameValidationResult | ScopedPackageNameValidationResult;
+
     /**
      * Validates package name using rules defined at https://docs.npmjs.com/files/package.json
      */
     export function validatePackageName(packageName: string): PackageNameValidationResult {
+        return validatePackageNameWorker(packageName, /*supportScopedPackage*/ true);
+    }
+
+    function validatePackageNameWorker(packageName: string, supportScopedPackage: false): NameValidationResult;
+    function validatePackageNameWorker(packageName: string, supportScopedPackage: true): PackageNameValidationResult;
+    function validatePackageNameWorker(packageName: string, supportScopedPackage: boolean): PackageNameValidationResult {
         if (!packageName) {
-            return PackageNameValidationResult.EmptyName;
+            return NameValidationResult.EmptyName;
         }
         if (packageName.length > maxPackageNameLength) {
-            return PackageNameValidationResult.NameTooLong;
+            return NameValidationResult.NameTooLong;
         }
         if (packageName.charCodeAt(0) === CharacterCodes.dot) {
-            return PackageNameValidationResult.NameStartsWithDot;
+            return NameValidationResult.NameStartsWithDot;
         }
         if (packageName.charCodeAt(0) === CharacterCodes._) {
-            return PackageNameValidationResult.NameStartsWithUnderscore;
+            return NameValidationResult.NameStartsWithUnderscore;
         }
         // check if name is scope package like: starts with @ and has one '/' in the middle
         // scoped packages are not currently supported
-        // TODO: when support will be added we'll need to split and check both scope and package name
-        if (/^@[^/]+\/[^/]+$/.test(packageName)) {
-            return PackageNameValidationResult.ScopedPackagesNotSupported;
+        if (supportScopedPackage) {
+            const matches = /^@([^/]+)\/([^/]+)$/.exec(packageName);
+            if (matches) {
+                const scopeResult = validatePackageNameWorker(matches[1], /*supportScopedPackage*/ false);
+                if (scopeResult !== NameValidationResult.Ok) {
+                    return { name: matches[1], isScopeName: true, result: scopeResult };
+                }
+                const packageResult = validatePackageNameWorker(matches[2], /*supportScopedPackage*/ false);
+                if (packageResult !== NameValidationResult.Ok) {
+                    return { name: matches[2], isScopeName: false, result: packageResult };
+                }
+                return NameValidationResult.Ok;
+            }
         }
         if (encodeURIComponent(packageName) !== packageName) {
-            return PackageNameValidationResult.NameContainsNonURISafeCharacters;
+            return NameValidationResult.NameContainsNonURISafeCharacters;
         }
-        return PackageNameValidationResult.Ok;
+        return NameValidationResult.Ok;
     }
 
     export function renderPackageNameValidationFailure(result: PackageNameValidationResult, typing: string): string {
+        return typeof result === "object" ?
+            renderPackageNameValidationFailureWorker(typing, result.result, result.name, result.isScopeName) :
+            renderPackageNameValidationFailureWorker(typing, result, typing, /*isScopeName*/ false);
+    }
+
+    function renderPackageNameValidationFailureWorker(typing: string, result: NameValidationResult, name: string, isScopeName: boolean): string {
+        const kind = isScopeName ? "Scope" : "Package";
         switch (result) {
-            case PackageNameValidationResult.EmptyName:
-                return `Package name '${typing}' cannot be empty`;
-            case PackageNameValidationResult.NameTooLong:
-                return `Package name '${typing}' should be less than ${maxPackageNameLength} characters`;
-            case PackageNameValidationResult.NameStartsWithDot:
-                return `Package name '${typing}' cannot start with '.'`;
-            case PackageNameValidationResult.NameStartsWithUnderscore:
-                return `Package name '${typing}' cannot start with '_'`;
-            case PackageNameValidationResult.ScopedPackagesNotSupported:
-                return `Package '${typing}' is scoped and currently is not supported`;
-            case PackageNameValidationResult.NameContainsNonURISafeCharacters:
-                return `Package name '${typing}' contains non URI safe characters`;
-            case PackageNameValidationResult.Ok:
+            case NameValidationResult.EmptyName:
+                return `'${typing}':: ${kind} name '${name}' cannot be empty`;
+            case NameValidationResult.NameTooLong:
+                return `'${typing}':: ${kind} name '${name}' should be less than ${maxPackageNameLength} characters`;
+            case NameValidationResult.NameStartsWithDot:
+                return `'${typing}':: ${kind} name '${name}' cannot start with '.'`;
+            case NameValidationResult.NameStartsWithUnderscore:
+                return `'${typing}':: ${kind} name '${name}' cannot start with '_'`;
+            case NameValidationResult.NameContainsNonURISafeCharacters:
+                return `'${typing}':: ${kind} name '${name}' contains non URI safe characters`;
+            case NameValidationResult.Ok:
                 return Debug.fail(); // Shouldn't have called this.
             default:
                 throw Debug.assertNever(result);

src/lib/es5.d.ts

@@ -12,7 +12,7 @@ declare var Infinity: number;
 declare function eval(x: string): any;
 
 /**
-  * Converts A string to an integer.
+  * Converts a string to an integer.
   * @param s A string to convert into a number.
   * @param radix A value between 2 and 36 that specifies the base of the number in numString.
   * If this argument is not supplied, strings with a prefix of '0x' are considered hexadecimal.

src/loc/lcl/ita/diagnosticMessages/diagnosticMessages.generated.json.lcl

@@ -1,4 +1,4 @@
-<?xml version="1.0" encoding="utf-8"?>
+<?xml version="1.0" encoding="utf-8"?>
 <LCX SchemaVersion="6.0" Name="f:\ddSetup\sources\typescript\localization\compiler2.resx" PsrId="306" FileType="1" SrcCul="en-US" TgtCul="it-IT" xmlns="http://schemas.microsoft.com/locstudio/2006/6/lcx">
   <Props>
     <Str Name="CustomName1" Val="Custom 1" />
@@ -3301,7 +3301,7 @@
         <Str Cat="Text">
           <Val><![CDATA[Emit the source alongside the sourcemaps within a single file; requires '--inlineSourceMap' or '--sourceMap' to be set.]]></Val>
           <Tgt Cat="Text" Stat="Loc" Orig="New">
-            <Val><![CDATA[Crea l'origine unitamente alle mappe di origine all'interno di un unico file. Richiede l'impostazione di '--inlineSourceMap' o '--sourceMap'.]]></Val>
+            <Val><![CDATA[Crea l'origine unitamente ai mapping di origine all'interno di un unico file. Richiede l'impostazione di '--inlineSourceMap' o '--sourceMap'.]]></Val>
           </Tgt>
         </Str>
         <Disp Icon="Str" />
@@ -4123,7 +4123,7 @@
         <Str Cat="Text">
           <Val><![CDATA[Generates a sourcemap for each corresponding '.d.ts' file.]]></Val>
           <Tgt Cat="Text" Stat="Loc" Orig="New">
-            <Val><![CDATA[Genera un sourcemap per ogni file '.d.ts' corrispondente.]]></Val>
+            <Val><![CDATA[Genera un mapping di origine per ogni file '.d.ts' corrispondente.]]></Val>
           </Tgt>
         </Str>
         <Disp Icon="Str" />

src/loc/lcl/rus/diagnosticMessages/diagnosticMessages.generated.json.lcl

@@ -1,4 +1,4 @@
-<?xml version="1.0" encoding="utf-8"?>
+<?xml version="1.0" encoding="utf-8"?>
 <LCX SchemaVersion="6.0" Name="f:\ddSetup\sources\typescript\localization\compiler2.resx" PsrId="306" FileType="1" SrcCul="en-US" TgtCul="ru-RU" xmlns="http://schemas.microsoft.com/locstudio/2006/6/lcx">
   <Props>
     <Str Name="CustomName1" Val="Custom 1" />
@@ -3300,7 +3300,7 @@
         <Str Cat="Text">
           <Val><![CDATA[Emit the source alongside the sourcemaps within a single file; requires '--inlineSourceMap' or '--sourceMap' to be set.]]></Val>
           <Tgt Cat="Text" Stat="Loc" Orig="New">
-            <Val><![CDATA[Порождать источник вместе с sourcemap в одном файле (нужно задать параметр --inlineSourceMap или --sourceMap).]]></Val>
+            <Val><![CDATA[Порождать источник вместе с сопоставителями с исходным кодом в одном файле (нужно задать параметр --inlineSourceMap или --sourceMap).]]></Val>
           </Tgt>
         </Str>
         <Disp Icon="Str" />
@@ -4122,7 +4122,7 @@
         <Str Cat="Text">
           <Val><![CDATA[Generates a sourcemap for each corresponding '.d.ts' file.]]></Val>
           <Tgt Cat="Text" Stat="Loc" Orig="New">
-            <Val><![CDATA[Создает sourcemap для каждого соответствующего файла ".d.ts".]]></Val>
+            <Val><![CDATA[Создает сопоставитель с исходным кодом для каждого соответствующего файла ".d.ts".]]></Val>
           </Tgt>
         </Str>
         <Disp Icon="Str" />

src/server/editorServices.ts

@@ -1087,7 +1087,24 @@ namespace ts.server {
 
             project.close();
             if (Debug.shouldAssert(AssertionLevel.Normal)) {
-                this.filenameToScriptInfo.forEach(info => Debug.assert(!info.isAttached(project), "Found script Info still attached to project", () => `${project.projectName}: ScriptInfos still attached: ${JSON.stringify(mapDefined(arrayFrom(this.filenameToScriptInfo.values()), info => info.isAttached(project) ? info : undefined))}`));
+                this.filenameToScriptInfo.forEach(info => Debug.assert(
+                    !info.isAttached(project),
+                    "Found script Info still attached to project",
+                    () => `${project.projectName}: ScriptInfos still attached: ${JSON.stringify(
+                        arrayFrom(
+                            mapDefinedIterator(
+                                this.filenameToScriptInfo.values(),
+                                info => info.isAttached(project) ?
+                                    {
+                                        fileName: info.fileName,
+                                        projects: info.containingProjects.map(p => p.projectName),
+                                        hasMixedContent: info.hasMixedContent
+                                    } : undefined
+                            )
+                        ),
+                        /*replacer*/ undefined,
+                        " "
+                    )}`));
             }
             // Remove the project from pending project updates
             this.pendingProjectUpdates.delete(project.getProjectName());

src/services/codefixes/importFixes.ts

@@ -283,25 +283,13 @@ namespace ts.codefix {
         preferences: UserPreferences,
     ): ReadonlyArray<FixAddNewImport | FixUseImportType> {
         const isJs = isSourceFileJS(sourceFile);
-        const { allowsImporting } = createLazyPackageJsonDependencyReader(sourceFile, host);
         const choicesForEachExportingModule = flatMap(moduleSymbols, ({ moduleSymbol, importKind, exportedSymbolIsTypeOnly }) =>
             moduleSpecifiers.getModuleSpecifiers(moduleSymbol, program.getCompilerOptions(), sourceFile, host, program.getSourceFiles(), preferences, program.redirectTargetsMap)
             .map((moduleSpecifier): FixAddNewImport | FixUseImportType =>
                 // `position` should only be undefined at a missing jsx namespace, in which case we shouldn't be looking for pure types.
                 exportedSymbolIsTypeOnly && isJs ? { kind: ImportFixKind.ImportType, moduleSpecifier, position: Debug.assertDefined(position) } : { kind: ImportFixKind.AddNew, moduleSpecifier, importKind }));
-
-        // Sort by presence in package.json, then shortest paths first
-        return sort(choicesForEachExportingModule, (a, b) => {
-            const allowsImportingA = allowsImporting(a.moduleSpecifier);
-            const allowsImportingB = allowsImporting(b.moduleSpecifier);
-            if (allowsImportingA && !allowsImportingB) {
-                return -1;
-            }
-            if (allowsImportingB && !allowsImportingA) {
-                return 1;
-            }
-            return a.moduleSpecifier.length - b.moduleSpecifier.length;
-        });
+        // Sort to keep the shortest paths first
+        return sort(choicesForEachExportingModule, (a, b) => a.moduleSpecifier.length - b.moduleSpecifier.length);
     }
 
     function getFixesForAddImport(
@@ -392,8 +380,7 @@ namespace ts.codefix {
         // "default" is a keyword and not a legal identifier for the import, so we don't expect it here
         Debug.assert(symbolName !== InternalSymbolName.Default);
 
-        const exportInfos = getExportInfos(symbolName, getMeaningFromLocation(symbolToken), cancellationToken, sourceFile, checker, program, preferences, host);
-        const fixes = arrayFrom(flatMapIterator(exportInfos.entries(), ([_, exportInfos]) =>
+        const fixes = arrayFrom(flatMapIterator(getExportInfos(symbolName, getMeaningFromLocation(symbolToken), cancellationToken, sourceFile, checker, program).entries(), ([_, exportInfos]) =>
             getFixForImport(exportInfos, symbolName, symbolToken.getStart(sourceFile), program, sourceFile, host, preferences)));
         return { fixes, symbolName };
     }
@@ -406,8 +393,6 @@ namespace ts.codefix {
         sourceFile: SourceFile,
         checker: TypeChecker,
         program: Program,
-        preferences: UserPreferences,
-        host: LanguageServiceHost
     ): ReadonlyMap<ReadonlyArray<SymbolExportInfo>> {
         // For each original symbol, keep all re-exports of that symbol together so we can call `getCodeActionsForImport` on the whole group at once.
         // Maps symbol id to info for modules providing that symbol (original export + re-exports).
@@ -415,7 +400,7 @@ namespace ts.codefix {
         function addSymbol(moduleSymbol: Symbol, exportedSymbol: Symbol, importKind: ImportKind): void {
             originalSymbolToExportInfos.add(getUniqueSymbolId(exportedSymbol, checker).toString(), { moduleSymbol, importKind, exportedSymbolIsTypeOnly: isTypeOnlySymbol(exportedSymbol, checker) });
         }
-        forEachExternalModuleToImportFrom(checker, host, preferences, program.redirectTargetsMap, sourceFile, program.getSourceFiles(), moduleSymbol => {
+        forEachExternalModuleToImportFrom(checker, sourceFile, program.getSourceFiles(), moduleSymbol => {
             cancellationToken.throwIfCancellationRequested();
 
             const defaultInfo = getDefaultLikeExportInfo(moduleSymbol, checker, program.getCompilerOptions());
@@ -576,44 +561,12 @@ namespace ts.codefix {
         return some(declarations, decl => !!(getMeaningFromDeclaration(decl) & meaning));
     }
 
-    export function forEachExternalModuleToImportFrom(checker: TypeChecker, host: LanguageServiceHost, preferences: UserPreferences, redirectTargetsMap: RedirectTargetsMap, from: SourceFile, allSourceFiles: ReadonlyArray<SourceFile>, cb: (module: Symbol) => void) {
-        const { allowsImporting } = createLazyPackageJsonDependencyReader(from, host);
-        const compilerOptions = host.getCompilationSettings();
-        const getCanonicalFileName = hostGetCanonicalFileName(host);
+    export function forEachExternalModuleToImportFrom(checker: TypeChecker, from: SourceFile, allSourceFiles: ReadonlyArray<SourceFile>, cb: (module: Symbol) => void) {
         forEachExternalModule(checker, allSourceFiles, (module, sourceFile) => {
-            if (sourceFile === undefined && allowsImporting(stripQuotes(module.getName()))) {
+            if (sourceFile === undefined || sourceFile !== from && isImportablePath(from.fileName, sourceFile.fileName)) {
                 cb(module);
             }
-            else if (sourceFile && sourceFile !== from && isImportablePath(from.fileName, sourceFile.fileName)) {
-                const moduleSpecifier = getNodeModulesPackageNameFromFileName(sourceFile.fileName);
-                if (!moduleSpecifier || allowsImporting(moduleSpecifier)) {
-                    cb(module);
-                }
-            }
         });
-
-        function getNodeModulesPackageNameFromFileName(importedFileName: string): string | undefined {
-            const specifier = moduleSpecifiers.getModuleSpecifier(
-                compilerOptions,
-                from,
-                toPath(from.fileName, /*basePath*/ undefined, getCanonicalFileName),
-                importedFileName,
-                host,
-                allSourceFiles,
-                preferences,
-                redirectTargetsMap);
-
-            // Paths here are not node_modules, so we don’t care about them;
-            // returning anything will trigger a lookup in package.json.
-            if (!pathIsRelative(specifier) && !isRootedDiskPath(specifier)) {
-                const components = getPathComponents(getPackageNameFromTypesPackageName(specifier)).slice(1);
-                // Scoped packages
-                if (startsWith(components[0], "@")) {
-                    return `${components[0]}/${components[1]}`;
-                }
-                return components[0];
-            }
-        }
     }
 
     function forEachExternalModule(checker: TypeChecker, allSourceFiles: ReadonlyArray<SourceFile>, cb: (module: Symbol, sourceFile: SourceFile | undefined) => void) {
@@ -667,69 +620,4 @@ namespace ts.codefix {
         // Need `|| "_"` to ensure result isn't empty.
         return !isStringANonContextualKeyword(res) ? res || "_" : `_${res}`;
     }
-
-    function createLazyPackageJsonDependencyReader(fromFile: SourceFile, host: LanguageServiceHost) {
-        const packageJsonPaths = findPackageJsons(getDirectoryPath(fromFile.fileName), host);
-        const dependencyIterator = readPackageJsonDependencies(host, packageJsonPaths);
-        let seenDeps: Map<true> | undefined;
-        let usesNodeCoreModules: boolean | undefined;
-        return { allowsImporting };
-
-        function containsDependency(dependency: string) {
-            if ((seenDeps || (seenDeps = createMap())).has(dependency)) {
-                return true;
-            }
-            let packageName: string | void;
-            while (packageName = dependencyIterator.next().value) {
-                seenDeps.set(packageName, true);
-                if (packageName === dependency) {
-                    return true;
-                }
-            }
-            return false;
-        }
-
-        function allowsImporting(moduleSpecifier: string): boolean {
-            if (!packageJsonPaths.length) {
-                return true;
-            }
-
-            // If we’re in JavaScript, it can be difficult to tell whether the user wants to import
-            // from Node core modules or not. We can start by seeing if the user is actually using
-            // any node core modules, as opposed to simply having @types/node accidentally as a
-            // dependency of a dependency.
-            if (isSourceFileJS(fromFile) && JsTyping.nodeCoreModules.has(moduleSpecifier)) {
-                if (usesNodeCoreModules === undefined) {
-                    usesNodeCoreModules = consumesNodeCoreModules(fromFile);
-                }
-                if (usesNodeCoreModules) {
-                    return true;
-                }
-            }
-
-            return containsDependency(moduleSpecifier)
-                || containsDependency(getTypesPackageName(moduleSpecifier));
-        }
-    }
-
-    function *readPackageJsonDependencies(host: LanguageServiceHost, packageJsonPaths: string[]) {
-        type PackageJson = Record<typeof dependencyKeys[number], Record<string, string> | undefined>;
-        const dependencyKeys = ["dependencies", "devDependencies", "optionalDependencies"] as const;
-        for (const fileName of packageJsonPaths) {
-            const content = readJson(fileName, { readFile: host.readFile ? host.readFile.bind(host) : sys.readFile }) as PackageJson;
-            for (const key of dependencyKeys) {
-                const dependencies = content[key];
-                if (!dependencies) {
-                    continue;
-                }
-                for (const packageName in dependencies) {
-                    yield packageName;
-                }
-            }
-        }
-    }
-
-    function consumesNodeCoreModules(sourceFile: SourceFile): boolean {
-        return some(sourceFile.imports, ({ text }) => JsTyping.nodeCoreModules.has(text));
-    }
 }

src/services/codefixes/removeUnnecessaryAwait.ts

@@ -0,0 +1,43 @@
+/* @internal */
+namespace ts.codefix {
+    const fixId = "removeUnnecessaryAwait";
+    const errorCodes = [
+        Diagnostics.await_has_no_effect_on_the_type_of_this_expression.code,
+    ];
+
+    registerCodeFix({
+        errorCodes,
+        getCodeActions: (context) => {
+            const changes = textChanges.ChangeTracker.with(context, t => makeChange(t, context.sourceFile, context.span));
+            if (changes.length > 0) {
+                return [createCodeFixAction(fixId, changes, Diagnostics.Remove_unnecessary_await, fixId, Diagnostics.Remove_all_unnecessary_uses_of_await)];
+            }
+        },
+        fixIds: [fixId],
+        getAllCodeActions: context => {
+            return codeFixAll(context, errorCodes, (changes, diag) => makeChange(changes, diag.file, diag));
+        },
+    });
+
+    function makeChange(changeTracker: textChanges.ChangeTracker, sourceFile: SourceFile, span: TextSpan) {
+        const awaitKeyword = tryCast(getTokenAtPosition(sourceFile, span.start), (node): node is AwaitKeywordToken => node.kind === SyntaxKind.AwaitKeyword);
+        const awaitExpression = awaitKeyword && tryCast(awaitKeyword.parent, isAwaitExpression);
+        if (!awaitExpression) {
+            return;
+        }
+
+        let expressionToReplace: Node = awaitExpression;
+        const hasSurroundingParens = isParenthesizedExpression(awaitExpression.parent);
+        if (hasSurroundingParens) {
+            const leftMostExpression = getLeftmostExpression(awaitExpression.expression, /*stopAtCallExpressions*/ false);
+            if (isIdentifier(leftMostExpression)) {
+                const precedingToken = findPrecedingToken(awaitExpression.parent.pos, sourceFile);
+                if (precedingToken && precedingToken.kind !== SyntaxKind.NewKeyword) {
+                    expressionToReplace = awaitExpression.parent;
+                }
+            }
+        }
+
+        changeTracker.replaceNode(sourceFile, expressionToReplace, awaitExpression.expression);
+    }
+}

src/services/completions.ts

@@ -38,6 +38,7 @@ namespace ts.Completions {
         InterfaceElementKeywords,       // Keywords inside interface body
         ConstructorParameterKeywords,   // Keywords at constructor parameter
         FunctionLikeBodyKeywords,       // Keywords at function like body
+        TypeAssertionKeywords,
         TypeKeywords,
         Last = TypeKeywords
     }
@@ -63,7 +64,7 @@ namespace ts.Completions {
             return getLabelCompletionAtPosition(contextToken.parent);
         }
 
-        const completionData = getCompletionData(program, log, sourceFile, isUncheckedFile(sourceFile, compilerOptions), position, preferences, /*detailsEntryId*/ undefined, host);
+        const completionData = getCompletionData(program, log, sourceFile, isUncheckedFile(sourceFile, compilerOptions), position, preferences, /*detailsEntryId*/ undefined);
         if (!completionData) {
             return undefined;
         }
@@ -406,10 +407,10 @@ namespace ts.Completions {
         previousToken: Node | undefined;
         readonly isJsxInitializer: IsJsxInitializer;
     }
-    function getSymbolCompletionFromEntryId(program: Program, log: Log, sourceFile: SourceFile, position: number, entryId: CompletionEntryIdentifier, host: LanguageServiceHost
+    function getSymbolCompletionFromEntryId(program: Program, log: Log, sourceFile: SourceFile, position: number, entryId: CompletionEntryIdentifier,
     ): SymbolCompletion | { type: "request", request: Request } | { type: "literal", literal: string | number | PseudoBigInt } | { type: "none" } {
         const compilerOptions = program.getCompilerOptions();
-        const completionData = getCompletionData(program, log, sourceFile, isUncheckedFile(sourceFile, compilerOptions), position, { includeCompletionsForModuleExports: true, includeCompletionsWithInsertText: true }, entryId, host);
+        const completionData = getCompletionData(program, log, sourceFile, isUncheckedFile(sourceFile, compilerOptions), position, { includeCompletionsForModuleExports: true, includeCompletionsWithInsertText: true }, entryId);
         if (!completionData) {
             return { type: "none" };
         }
@@ -441,7 +442,7 @@ namespace ts.Completions {
             (symbol.escapedName === InternalSymbolName.ExportEquals))
             // Name of "export default foo;" is "foo". Name of "export default 0" is the filename converted to camelCase.
             ? firstDefined(symbol.declarations, d => isExportAssignment(d) && isIdentifier(d.expression) ? d.expression.text : undefined)
-                || codefix.moduleSymbolToValidIdentifier(origin.moduleSymbol, target)
+            || codefix.moduleSymbolToValidIdentifier(origin.moduleSymbol, target)
             : symbol.name;
     }
 
@@ -471,7 +472,7 @@ namespace ts.Completions {
         }
 
         // Compute all the completion symbols again.
-        const symbolCompletion = getSymbolCompletionFromEntryId(program, log, sourceFile, position, entryId, host);
+        const symbolCompletion = getSymbolCompletionFromEntryId(program, log, sourceFile, position, entryId);
         switch (symbolCompletion.type) {
             case "request": {
                 const { request } = symbolCompletion;
@@ -556,8 +557,8 @@ namespace ts.Completions {
         return { sourceDisplay: [textPart(moduleSpecifier)], codeActions: [codeAction] };
     }
 
-    export function getCompletionEntrySymbol(program: Program, log: Log, sourceFile: SourceFile, position: number, entryId: CompletionEntryIdentifier, host: LanguageServiceHost): Symbol | undefined {
-        const completion = getSymbolCompletionFromEntryId(program, log, sourceFile, position, entryId, host);
+    export function getCompletionEntrySymbol(program: Program, log: Log, sourceFile: SourceFile, position: number, entryId: CompletionEntryIdentifier): Symbol | undefined {
+        const completion = getSymbolCompletionFromEntryId(program, log, sourceFile, position, entryId);
         return completion.type === "symbol" ? completion.symbol : undefined;
     }
 
@@ -632,9 +633,9 @@ namespace ts.Completions {
                     // At `,`, treat this as the next argument after the comma.
                     ? checker.getContextualTypeForArgumentAtIndex(argInfo.invocation, argInfo.argumentIndex + (previousToken.kind === SyntaxKind.CommaToken ? 1 : 0))
                     : isEqualityOperatorKind(previousToken.kind) && isBinaryExpression(parent) && isEqualityOperatorKind(parent.operatorToken.kind)
-                    // completion at `x ===/**/` should be for the right side
-                    ? checker.getTypeAtLocation(parent.left)
-                    : checker.getContextualType(previousToken as Expression);
+                        // completion at `x ===/**/` should be for the right side
+                        ? checker.getTypeAtLocation(parent.left)
+                        : checker.getContextualType(previousToken as Expression);
         }
     }
 
@@ -656,7 +657,6 @@ namespace ts.Completions {
         position: number,
         preferences: Pick<UserPreferences, "includeCompletionsForModuleExports" | "includeCompletionsWithInsertText">,
         detailsEntryId: CompletionEntryIdentifier | undefined,
-        host: LanguageServiceHost
     ): CompletionData | Request | undefined {
         const typeChecker = program.getTypeChecker();
 
@@ -947,11 +947,13 @@ namespace ts.Completions {
             // Right of dot member completion list
             completionKind = CompletionKind.PropertyAccess;
 
-            // Since this is qualified name check its a type node location
+            // Since this is qualified name check it's a type node location
             const isImportType = isLiteralImportTypeNode(node);
-            const isTypeLocation = insideJsDocTagTypeExpression || (isImportType && !(node as ImportTypeNode).isTypeOf) || isPartOfTypeNode(node.parent);
+            const isTypeLocation = insideJsDocTagTypeExpression
+                || (isImportType && !(node as ImportTypeNode).isTypeOf)
+                || isPartOfTypeNode(node.parent)
+                || isPossiblyTypeArgumentPosition(contextToken, sourceFile, typeChecker);
             const isRhsOfImportDeclaration = isInRightSideOfInternalImportEqualsDeclaration(node);
-            const allowTypeOrValue = isRhsOfImportDeclaration || (!isTypeLocation && isPossiblyTypeArgumentPosition(contextToken, sourceFile, typeChecker));
             if (isEntityName(node) || isImportType) {
                 const isNamespaceName = isModuleDeclaration(node.parent);
                 if (isNamespaceName) isNewIdentifierLocation = true;
@@ -968,7 +970,7 @@ namespace ts.Completions {
                             isNamespaceName
                                 // At `namespace N.M/**/`, if this is the only declaration of `M`, don't include `M` as a completion.
                                 ? symbol => !!(symbol.flags & SymbolFlags.Namespace) && !symbol.declarations.every(d => d.parent === node.parent)
-                                : allowTypeOrValue ?
+                                : isRhsOfImportDeclaration ?
                                     // Any kind is allowed when dotting off namespace in internal import equals declaration
                                     symbol => isValidTypeAccess(symbol) || isValidValueAccess(symbol) :
                                     isTypeLocation ? isValidTypeAccess : isValidValueAccess;
@@ -1149,7 +1151,7 @@ namespace ts.Completions {
             }
 
             if (shouldOfferImportCompletions()) {
-                getSymbolsFromOtherSourceFileExports(symbols, previousToken && isIdentifier(previousToken) ? previousToken.text : "", program.getCompilerOptions().target!, host);
+                getSymbolsFromOtherSourceFileExports(symbols, previousToken && isIdentifier(previousToken) ? previousToken.text : "", program.getCompilerOptions().target!);
             }
             filterGlobalCompletion(symbols);
         }
@@ -1181,8 +1183,11 @@ namespace ts.Completions {
 
         function filterGlobalCompletion(symbols: Symbol[]): void {
             const isTypeOnly = isTypeOnlyCompletion();
-            const allowTypes = isTypeOnly || !isContextTokenValueLocation(contextToken) && isPossiblyTypeArgumentPosition(contextToken, sourceFile, typeChecker);
-            if (isTypeOnly) keywordFilters = KeywordCompletionFilters.TypeKeywords;
+            if (isTypeOnly) {
+                keywordFilters = isTypeAssertion()
+                    ? KeywordCompletionFilters.TypeAssertionKeywords
+                    : KeywordCompletionFilters.TypeKeywords;
+            }
 
             filterMutate(symbols, symbol => {
                 if (!isSourceFile(location)) {
@@ -1198,12 +1203,9 @@ namespace ts.Completions {
                         return !!(symbol.flags & SymbolFlags.Namespace);
                     }
 
-                    if (allowTypes) {
-                        // Its a type, but you can reach it by namespace.type as well
-                        const symbolAllowedAsType = symbolCanBeReferencedAtTypeLocation(symbol);
-                        if (symbolAllowedAsType || isTypeOnly) {
-                            return symbolAllowedAsType;
-                        }
+                    if (isTypeOnly) {
+                        // It's a type, but you can reach it by namespace.type as well
+                        return symbolCanBeReferencedAtTypeLocation(symbol);
                     }
                 }
 
@@ -1212,8 +1214,16 @@ namespace ts.Completions {
             });
         }
 
+        function isTypeAssertion(): boolean {
+            return isAssertionExpression(contextToken.parent);
+        }
+
         function isTypeOnlyCompletion(): boolean {
-            return insideJsDocTagTypeExpression || !isContextTokenValueLocation(contextToken) && (isPartOfTypeNode(location) || isContextTokenTypeLocation(contextToken));
+            return insideJsDocTagTypeExpression
+                || !isContextTokenValueLocation(contextToken) &&
+                (isPossiblyTypeArgumentPosition(contextToken, sourceFile, typeChecker)
+                 || isPartOfTypeNode(location)
+                 || isContextTokenTypeLocation(contextToken));
         }
 
         function isContextTokenValueLocation(contextToken: Node) {
@@ -1239,6 +1249,10 @@ namespace ts.Completions {
                     case SyntaxKind.AsKeyword:
                         return parentKind === SyntaxKind.AsExpression;
 
+                    case SyntaxKind.LessThanToken:
+                        return parentKind === SyntaxKind.TypeReference ||
+                            parentKind === SyntaxKind.TypeAssertionExpression;
+
                     case SyntaxKind.ExtendsKeyword:
                         return parentKind === SyntaxKind.TypeParameter;
                 }
@@ -1255,64 +1269,12 @@ namespace ts.Completions {
                 typeChecker.getExportsOfModule(sym).some(e => symbolCanBeReferencedAtTypeLocation(e, seenModules));
         }
 
-        /**
-         * Gathers symbols that can be imported from other files, deduplicating along the way. Symbols can be “duplicates”
-         * if re-exported from another module, e.g. `export { foo } from "./a"`. That syntax creates a fresh symbol, but
-         * it’s just an alias to the first, and both have the same name, so we generally want to filter those aliases out,
-         * if and only if the the first can be imported (it may be excluded due to package.json filtering in
-         * `codefix.forEachExternalModuleToImportFrom`).
-         *
-         * Example. Imagine a chain of node_modules re-exporting one original symbol:
-         *
-         * ```js
-         *  node_modules/x/index.js         node_modules/y/index.js           node_modules/z/index.js
-         * +-----------------------+      +--------------------------+      +--------------------------+
-         * |                       |      |                          |      |                          |
-         * | export const foo = 0; | <--- | export { foo } from 'x'; | <--- | export { foo } from 'y'; |
-         * |                       |      |                          |      |                          |
-         * +-----------------------+      +--------------------------+      +--------------------------+
-         * ```
-         *
-         * Also imagine three buckets, which we’ll reference soon:
-         *
-         * ```md
-         * |                  |      |                      |      |                   |
-         * |   **Bucket A**   |      |    **Bucket B**      |      |    **Bucket C**   |
-         * |    Symbols to    |      | Aliases to symbols   |      | Symbols to return |
-         * |    definitely    |      | in Buckets A or C    |      | if nothing better |
-         * |      return      |      | (don’t return these) |      |    comes along    |
-         * |__________________|      |______________________|      |___________________|
-         * ```
-         *
-         * We _probably_ want to show `foo` from 'x', but not from 'y' or 'z'. However, if 'x' is not in a package.json, it
-         * will not appear in a `forEachExternalModuleToImportFrom` iteration. Furthermore, the order of iterations is not
-         * guaranteed, as it is host-dependent. Therefore, when presented with the symbol `foo` from module 'y' alone, we
-         * may not be sure whether or not it should go in the list. So, we’ll take the following steps:
-         *
-         * 1. Resolve alias `foo` from 'y' to the export declaration in 'x', get the symbol there, and see if that symbol is
-         *    already in Bucket A (symbols we already know will be returned). If it is, put `foo` from 'y' in Bucket B
-         *    (symbols that are aliases to symbols in Bucket A). If it’s not, put it in Bucket C.
-         * 2. Next, imagine we see `foo` from module 'z'. Again, we resolve the alias to the nearest export, which is in 'y'.
-         *    At this point, if that nearest export from 'y' is in _any_ of the three buckets, we know the symbol in 'z'
-         *    should never be returned in the final list, so put it in Bucket B.
-         * 3. Next, imagine we see `foo` from module 'x', the original. Syntactically, it doesn’t look like a re-export, so
-         *    we can just check Bucket C to see if we put any aliases to the original in there. If they exist, throw them out.
-         *    Put this symbol in Bucket A.
-         * 4. After we’ve iterated through every symbol of every module, any symbol left in Bucket C means that step 3 didn’t
-         *    occur for that symbol---that is, the original symbol is not in Bucket A, so we should include the alias. Move
-         *    everything from Bucket C to Bucket A.
-         *
-         * Note: Bucket A is passed in as the parameter `symbols` and mutated.
-         */
-        function getSymbolsFromOtherSourceFileExports(/** Bucket A */ symbols: Symbol[], tokenText: string, target: ScriptTarget, host: LanguageServiceHost): void {
+        function getSymbolsFromOtherSourceFileExports(symbols: Symbol[], tokenText: string, target: ScriptTarget): void {
             const tokenTextLowerCase = tokenText.toLowerCase();
-            const seenResolvedModules = createMap<true>();
-            /** Bucket B */
-            const aliasesToAlreadyIncludedSymbols = createMap<true>();
-            /** Bucket C */
-            const aliasesToReturnIfOriginalsAreMissing = createMap<{ alias: Symbol, moduleSymbol: Symbol }>();
 
-            codefix.forEachExternalModuleToImportFrom(typeChecker, host, preferences, program.redirectTargetsMap, sourceFile, program.getSourceFiles(), moduleSymbol => {
+            const seenResolvedModules = createMap<true>();
+
+            codefix.forEachExternalModuleToImportFrom(typeChecker, sourceFile, program.getSourceFiles(), moduleSymbol => {
                 // Perf -- ignore other modules if this is a request for details
                 if (detailsEntryId && detailsEntryId.source && stripQuotes(moduleSymbol.name) !== detailsEntryId.source) {
                     return;
@@ -1333,59 +1295,33 @@ namespace ts.Completions {
                     symbolToOriginInfoMap[getSymbolId(resolvedModuleSymbol)] = { kind: SymbolOriginInfoKind.Export, moduleSymbol, isDefaultExport: false };
                 }
 
-                for (const symbol of typeChecker.getExportsOfModule(moduleSymbol)) {
-                    // If this is `export { _break as break };` (a keyword) -- skip this and prefer the keyword completion.
-                    if (some(symbol.declarations, d => isExportSpecifier(d) && !!d.propertyName && isIdentifierANonContextualKeyword(d.name))) {
+                for (let symbol of typeChecker.getExportsOfModule(moduleSymbol)) {
+                    // Don't add a completion for a re-export, only for the original.
+                    // The actual import fix might end up coming from a re-export -- we don't compute that until getting completion details.
+                    // This is just to avoid adding duplicate completion entries.
+                    //
+                    // If `symbol.parent !== ...`, this is an `export * from "foo"` re-export. Those don't create new symbols.
+                    if (typeChecker.getMergedSymbol(symbol.parent!) !== resolvedModuleSymbol
+                        || some(symbol.declarations, d =>
+                            // If `!!d.name.originalKeywordKind`, this is `export { _break as break };` -- skip this and prefer the keyword completion.
+                            // If `!!d.parent.parent.moduleSpecifier`, this is `export { foo } from "foo"` re-export, which creates a new symbol (thus isn't caught by the first check).
+                            isExportSpecifier(d) && (d.propertyName ? isIdentifierANonContextualKeyword(d.name) : !!d.parent.parent.moduleSpecifier))) {
                         continue;
                     }
-                    // If `symbol.parent !== moduleSymbol`, this is an `export * from "foo"` re-export. Those don't create new symbols.
-                    const isExportStarFromReExport = typeChecker.getMergedSymbol(symbol.parent!) !== resolvedModuleSymbol;
-                    // If `!!d.parent.parent.moduleSpecifier`, this is `export { foo } from "foo"` re-export, which creates a new symbol (thus isn't caught by the first check).
-                    if (isExportStarFromReExport || some(symbol.declarations, d => isExportSpecifier(d) && !d.propertyName && !!d.parent.parent.moduleSpecifier)) {
-                        // Walk the export chain back one module (step 1 or 2 in diagrammed example).
-                        // Or, in the case of `export * from "foo"`, `symbol` already points to the original export, so just use that.
-                        const nearestExportSymbolId = getSymbolId(isExportStarFromReExport ? symbol : Debug.assertDefined(getNearestExportSymbol(symbol)));
-                        const symbolHasBeenSeen = !!symbolToOriginInfoMap[nearestExportSymbolId] || aliasesToAlreadyIncludedSymbols.has(nearestExportSymbolId.toString());
-                        if (!symbolHasBeenSeen) {
-                            aliasesToReturnIfOriginalsAreMissing.set(nearestExportSymbolId.toString(), { alias: symbol, moduleSymbol });
-                            aliasesToAlreadyIncludedSymbols.set(getSymbolId(symbol).toString(), true);
-                        }
-                        else {
-                            // Perf - we know this symbol is an alias to one that’s already covered in `symbols`, so store it here
-                            // in case another symbol re-exports this one; that way we can short-circuit as soon as we see this symbol id.
-                            addToSeen(aliasesToAlreadyIncludedSymbols, getSymbolId(symbol));
-                        }
+
+                    const isDefaultExport = symbol.escapedName === InternalSymbolName.Default;
+                    if (isDefaultExport) {
+                        symbol = getLocalSymbolForExportDefault(symbol) || symbol;
                     }
-                    else {
-                        // This is not a re-export, so see if we have any aliases pending and remove them (step 3 in diagrammed example)
-                        aliasesToReturnIfOriginalsAreMissing.delete(getSymbolId(symbol).toString());
-                        pushSymbol(symbol, moduleSymbol);
+
+                    const origin: SymbolOriginInfoExport = { kind: SymbolOriginInfoKind.Export, moduleSymbol, isDefaultExport };
+                    if (detailsEntryId || stringContainsCharactersInOrder(getSymbolName(symbol, origin, target).toLowerCase(), tokenTextLowerCase)) {
+                        symbols.push(symbol);
+                        symbolToSortTextMap[getSymbolId(symbol)] = SortText.AutoImportSuggestions;
+                        symbolToOriginInfoMap[getSymbolId(symbol)] = origin;
                     }
                 }
             });
-
-            // By this point, any potential duplicates that were actually duplicates have been
-            // removed, so the rest need to be added. (Step 4 in diagrammed example)
-            aliasesToReturnIfOriginalsAreMissing.forEach(({ alias, moduleSymbol }) => pushSymbol(alias, moduleSymbol));
-
-            function pushSymbol(symbol: Symbol, moduleSymbol: Symbol) {
-                const isDefaultExport = symbol.escapedName === InternalSymbolName.Default;
-                if (isDefaultExport) {
-                    symbol = getLocalSymbolForExportDefault(symbol) || symbol;
-                }
-                const origin: SymbolOriginInfoExport = { kind: SymbolOriginInfoKind.Export, moduleSymbol, isDefaultExport };
-                if (detailsEntryId || stringContainsCharactersInOrder(getSymbolName(symbol, origin, target).toLowerCase(), tokenTextLowerCase)) {
-                    symbols.push(symbol);
-                    symbolToSortTextMap[getSymbolId(symbol)] = SortText.AutoImportSuggestions;
-                    symbolToOriginInfoMap[getSymbolId(symbol)] = origin;
-                }
-            }
-        }
-
-        function getNearestExportSymbol(fromSymbol: Symbol) {
-            return findAlias(typeChecker, fromSymbol, alias => {
-                return some(alias.declarations, d => isExportSpecifier(d) || !!d.localSymbol);
-            });
         }
 
         /**
@@ -1513,7 +1449,7 @@ namespace ts.Completions {
             //   3. at the end of a regular expression (due to trailing flags like '/foo/g').
             return (isRegularExpressionLiteral(contextToken) || isStringTextContainingNode(contextToken)) && (
                 rangeContainsPositionExclusive(createTextRangeFromSpan(createTextSpanFromNode(contextToken)), position) ||
-                    position === contextToken.end && (!!contextToken.isUnterminated || isRegularExpressionLiteral(contextToken)));
+                position === contextToken.end && (!!contextToken.isUnterminated || isRegularExpressionLiteral(contextToken)));
         }
 
         /**
@@ -1617,7 +1553,7 @@ namespace ts.Completions {
          * Relevant symbols are stored in the captured 'symbols' variable.
          */
         function tryGetClassLikeCompletionSymbols(): GlobalsSearch {
-            const decl = tryGetObjectTypeDeclarationCompletionContainer(sourceFile, contextToken, location);
+            const decl = tryGetObjectTypeDeclarationCompletionContainer(sourceFile, contextToken, location, position);
             if (!decl) return GlobalsSearch.Continue;
 
             // We're looking up possible property names from parent type.
@@ -2023,8 +1959,8 @@ namespace ts.Completions {
 
             return baseSymbols.filter(propertySymbol =>
                 !existingMemberNames.has(propertySymbol.escapedName) &&
-                    !!propertySymbol.declarations &&
-                    !(getDeclarationModifierFlagsFromSymbol(propertySymbol) & ModifierFlags.Private));
+                !!propertySymbol.declarations &&
+                !(getDeclarationModifierFlagsFromSymbol(propertySymbol) & ModifierFlags.Private));
         }
 
         /**
@@ -2126,16 +2062,20 @@ namespace ts.Completions {
                 case KeywordCompletionFilters.None:
                     return false;
                 case KeywordCompletionFilters.All:
-                    return kind === SyntaxKind.AsyncKeyword || SyntaxKind.AwaitKeyword || !isContextualKeyword(kind) && !isClassMemberCompletionKeyword(kind) || kind === SyntaxKind.DeclareKeyword || kind === SyntaxKind.ModuleKeyword
+                    return isFunctionLikeBodyKeyword(kind)
+                        || kind === SyntaxKind.DeclareKeyword
+                        || kind === SyntaxKind.ModuleKeyword
                         || isTypeKeyword(kind) && kind !== SyntaxKind.UndefinedKeyword;
+                case KeywordCompletionFilters.FunctionLikeBodyKeywords:
+                    return isFunctionLikeBodyKeyword(kind);
                 case KeywordCompletionFilters.ClassElementKeywords:
                     return isClassMemberCompletionKeyword(kind);
                 case KeywordCompletionFilters.InterfaceElementKeywords:
                     return isInterfaceOrTypeLiteralCompletionKeyword(kind);
                 case KeywordCompletionFilters.ConstructorParameterKeywords:
                     return isParameterPropertyModifier(kind);
-                case KeywordCompletionFilters.FunctionLikeBodyKeywords:
-                    return isFunctionLikeBodyKeyword(kind);
+                case KeywordCompletionFilters.TypeAssertionKeywords:
+                    return isTypeKeyword(kind) || kind === SyntaxKind.ConstKeyword;
                 case KeywordCompletionFilters.TypeKeywords:
                     return isTypeKeyword(kind);
                 default:
@@ -2196,7 +2136,9 @@ namespace ts.Completions {
     }
 
     function isFunctionLikeBodyKeyword(kind: SyntaxKind) {
-        return kind === SyntaxKind.AsyncKeyword || kind === SyntaxKind.AwaitKeyword || !isContextualKeyword(kind) && !isClassMemberCompletionKeyword(kind);
+        return kind === SyntaxKind.AsyncKeyword
+            || kind === SyntaxKind.AwaitKeyword
+            || !isContextualKeyword(kind) && !isClassMemberCompletionKeyword(kind);
     }
 
     function keywordForNode(node: Node): SyntaxKind {
@@ -2234,7 +2176,7 @@ namespace ts.Completions {
      * Returns the immediate owning class declaration of a context token,
      * on the condition that one exists and that the context implies completion should be given.
      */
-    function tryGetObjectTypeDeclarationCompletionContainer(sourceFile: SourceFile, contextToken: Node | undefined, location: Node): ObjectTypeDeclaration | undefined {
+    function tryGetObjectTypeDeclarationCompletionContainer(sourceFile: SourceFile, contextToken: Node | undefined, location: Node, position: number): ObjectTypeDeclaration | undefined {
         // class c { method() { } | method2() { } }
         switch (location.kind) {
             case SyntaxKind.SyntaxList:
@@ -2244,9 +2186,15 @@ namespace ts.Completions {
                 if (cls && !findChildOfKind(cls, SyntaxKind.CloseBraceToken, sourceFile)) {
                     return cls;
                 }
+                break;
+            case SyntaxKind.Identifier: // class c extends React.Component { a: () => 1\n compon| }
+                if (isFromObjectTypeDeclaration(location)) {
+                    return findAncestor(location, isObjectTypeDeclaration);
+                }
         }
 
         if (!contextToken) return undefined;
+
         switch (contextToken.kind) {
             case SyntaxKind.SemicolonToken: // class c {getValue(): number; | }
             case SyntaxKind.CloseBraceToken: // class c { method() { } | }
@@ -2258,7 +2206,13 @@ namespace ts.Completions {
             case SyntaxKind.CommaToken: // class c {getValue(): number, | }
                 return tryCast(contextToken.parent, isObjectTypeDeclaration);
             default:
-                if (!isFromObjectTypeDeclaration(contextToken)) return undefined;
+                if (!isFromObjectTypeDeclaration(contextToken)) {
+                    // class c extends React.Component { a: () => 1\n| }
+                    if (getLineAndCharacterOfPosition(sourceFile, contextToken.getEnd()).line !== getLineAndCharacterOfPosition(sourceFile, position).line && isObjectTypeDeclaration(location)) {
+                        return location;
+                    }
+                    return undefined;
+                }
                 const isValidKeyword = isClassLike(contextToken.parent.parent) ? isClassMemberCompletionKeyword : isInterfaceOrTypeLiteralCompletionKeyword;
                 return (isValidKeyword(contextToken.kind) || contextToken.kind === SyntaxKind.AsteriskToken || isIdentifier(contextToken) && isValidKeyword(stringToToken(contextToken.text)!)) // TODO: GH#18217
                     ? contextToken.parent.parent as ObjectTypeDeclaration : undefined;
@@ -2295,13 +2249,4 @@ namespace ts.Completions {
     function binaryExpressionMayBeOpenTag({ left }: BinaryExpression): boolean {
         return nodeIsMissing(left);
     }
-
-    function findAlias(typeChecker: TypeChecker, symbol: Symbol, predicate: (symbol: Symbol) => boolean): Symbol | undefined {
-        let currentAlias: Symbol | undefined = symbol;
-        while (currentAlias.flags & SymbolFlags.Alias && (currentAlias = typeChecker.getImmediateAliasedSymbol(currentAlias))) {
-            if (predicate(currentAlias)) {
-                return currentAlias;
-            }
-        }
-    }
 }

src/services/formatting/formatting.ts

@@ -490,6 +490,9 @@ namespace ts.formatting {
                 else if (SmartIndenter.childStartsOnTheSameLineWithElseInIfStatement(parent, node, startLine, sourceFile)) {
                     return { indentation: parentDynamicIndentation.getIndentation(), delta };
                 }
+                else if (SmartIndenter.argumentStartsOnSameLineAsPreviousArgument(parent, node, startLine, sourceFile)) {
+                    return { indentation: parentDynamicIndentation.getIndentation(), delta };
+                }
                 else {
                     return { indentation: parentDynamicIndentation.getIndentation() + parentDynamicIndentation.getDelta(node), delta };
                 }

src/services/formatting/smartIndenter.ts

@@ -322,6 +322,25 @@ namespace ts.formatting {
             return false;
         }
 
+        export function argumentStartsOnSameLineAsPreviousArgument(parent: Node, child: TextRangeWithKind, childStartLine: number, sourceFile: SourceFileLike): boolean {
+            if (isCallOrNewExpression(parent)) {
+                if (!parent.arguments) return false;
+
+                const currentNode = Debug.assertDefined(find(parent.arguments, arg => arg.pos === child.pos));
+                const currentIndex = parent.arguments.indexOf(currentNode);
+                if (currentIndex === 0) return false; // Can't look at previous node if first
+
+                const previousNode = parent.arguments[currentIndex - 1];
+                const lineOfPreviousNode = getLineAndCharacterOfPosition(sourceFile, previousNode.getEnd()).line;
+
+                if (childStartLine === lineOfPreviousNode) {
+                    return true;
+                }
+            }
+
+            return false;
+        }
+
         export function getContainingList(node: Node, sourceFile: SourceFile): NodeArray<Node> | undefined {
             return node.parent && getListByRange(node.getStart(sourceFile), node.getEnd(), node.parent, sourceFile);
         }

src/services/outliningElementsCollector.ts

@@ -198,6 +198,8 @@ namespace ts.OutliningElementsCollector {
                 return spanForObjectOrArrayLiteral(n, SyntaxKind.OpenBracketToken);
             case SyntaxKind.JsxElement:
                 return spanForJSXElement(<JsxElement>n);
+            case SyntaxKind.JsxFragment:
+                return spanForJSXFragment(<JsxFragment>n);
             case SyntaxKind.JsxSelfClosingElement:
             case SyntaxKind.JsxOpeningElement:
                 return spanForJSXAttributes((<JsxOpeningLikeElement>n).attributes);
@@ -210,6 +212,12 @@ namespace ts.OutliningElementsCollector {
             return createOutliningSpan(textSpan, OutliningSpanKind.Code, textSpan, /*autoCollapse*/ false, bannerText);
         }
 
+        function spanForJSXFragment(node: JsxFragment): OutliningSpan | undefined {
+            const textSpan = createTextSpanFromBounds(node.openingFragment.getStart(sourceFile), node.closingFragment.getEnd());
+            const bannerText = "<>...</>";
+            return createOutliningSpan(textSpan, OutliningSpanKind.Code, textSpan, /*autoCollapse*/ false, bannerText);
+        }
+
         function spanForJSXAttributes(node: JsxAttributes): OutliningSpan | undefined {
             if (node.properties.length === 0) {
                 return undefined;

src/services/services.ts

@@ -1453,7 +1453,7 @@ namespace ts {
 
         function getCompletionEntrySymbol(fileName: string, position: number, name: string, source?: string): Symbol | undefined {
             synchronizeHostData();
-            return Completions.getCompletionEntrySymbol(program, log, getValidSourceFile(fileName), position, { name, source }, host);
+            return Completions.getCompletionEntrySymbol(program, log, getValidSourceFile(fileName), position, { name, source });
         }
 
         function getQuickInfoAtPosition(fileName: string, position: number): QuickInfo | undefined {

src/services/stringCompletions.ts

@@ -627,6 +627,30 @@ namespace ts.Completions.StringCompletions {
         }
     }
 
+    function findPackageJsons(directory: string, host: LanguageServiceHost): string[] {
+        const paths: string[] = [];
+        forEachAncestorDirectory(directory, ancestor => {
+            const currentConfigPath = findConfigFile(ancestor, (f) => tryFileExists(host, f), "package.json");
+            if (!currentConfigPath) {
+                return true; // break out
+            }
+            paths.push(currentConfigPath);
+        });
+        return paths;
+    }
+
+    function findPackageJson(directory: string, host: LanguageServiceHost): string | undefined {
+        let packageJson: string | undefined;
+        forEachAncestorDirectory(directory, ancestor => {
+            if (ancestor === "node_modules") return true;
+            packageJson = findConfigFile(ancestor, (f) => tryFileExists(host, f), "package.json");
+            if (packageJson) {
+                return true; // break out
+            }
+        });
+        return packageJson;
+    }
+
     function enumerateNodeModulesVisibleToScript(host: LanguageServiceHost, scriptPath: string): ReadonlyArray<string> {
         if (!host.readFile || !host.fileExists) return emptyArray;
 
@@ -682,6 +706,31 @@ namespace ts.Completions.StringCompletions {
 
     const nodeModulesDependencyKeys: ReadonlyArray<string> = ["dependencies", "devDependencies", "peerDependencies", "optionalDependencies"];
 
+    function tryGetDirectories(host: LanguageServiceHost, directoryName: string): string[] {
+        return tryIOAndConsumeErrors(host, host.getDirectories, directoryName) || [];
+    }
+
+    function tryReadDirectory(host: LanguageServiceHost, path: string, extensions?: ReadonlyArray<string>, exclude?: ReadonlyArray<string>, include?: ReadonlyArray<string>): ReadonlyArray<string> {
+        return tryIOAndConsumeErrors(host, host.readDirectory, path, extensions, exclude, include) || emptyArray;
+    }
+
+    function tryFileExists(host: LanguageServiceHost, path: string): boolean {
+        return tryIOAndConsumeErrors(host, host.fileExists, path);
+    }
+
+    function tryDirectoryExists(host: LanguageServiceHost, path: string): boolean {
+        return tryAndIgnoreErrors(() => directoryProbablyExists(path, host)) || false;
+    }
+
+    function tryIOAndConsumeErrors<T>(host: LanguageServiceHost, toApply: ((...a: any[]) => T) | undefined, ...args: any[]) {
+        return tryAndIgnoreErrors(() => toApply && toApply.apply(host, args));
+    }
+
+    function tryAndIgnoreErrors<T>(cb: () => T): T | undefined {
+        try { return cb(); }
+        catch { return undefined; }
+    }
+
     function containsSlash(fragment: string) {
         return stringContains(fragment, directorySeparator);
     }

src/services/tsconfig.json

@@ -80,6 +80,7 @@
         "codefixes/useDefaultImport.ts",
         "codefixes/fixAddModuleReferTypeMissingTypeof.ts",
         "codefixes/convertToMappedObjectType.ts",
+        "codefixes/removeUnnecessaryAwait.ts",
         "refactors/convertExport.ts",
         "refactors/convertImport.ts",
         "refactors/extractSymbol.ts",

src/services/types.ts

@@ -892,7 +892,7 @@ namespace ts {
     }
 
     export interface CompletionInfo {
-        /** Not true for all glboal completions. This will be true if the enclosing scope matches a few syntax kinds. See `isSnippetScope`. */
+        /** Not true for all global completions. This will be true if the enclosing scope matches a few syntax kinds. See `isSnippetScope`. */
         isGlobalCompletion: boolean;
         isMemberCompletion: boolean;
 

src/services/utilities.ts

@@ -1224,6 +1224,7 @@ namespace ts {
         SyntaxKind.NullKeyword,
         SyntaxKind.NumberKeyword,
         SyntaxKind.ObjectKeyword,
+        SyntaxKind.ReadonlyKeyword,
         SyntaxKind.StringKeyword,
         SyntaxKind.SymbolKeyword,
         SyntaxKind.TrueKeyword,
@@ -1636,23 +1637,6 @@ namespace ts {
         return !!location.parent && isImportOrExportSpecifier(location.parent) && location.parent.propertyName === location;
     }
 
-    /**
-     * Strip off existed single quotes or double quotes from a given string
-     *
-     * @return non-quoted string
-     */
-    export function stripQuotes(name: string) {
-        const length = name.length;
-        if (length >= 2 && name.charCodeAt(0) === name.charCodeAt(length - 1) && startsWithQuote(name)) {
-            return name.substring(1, length - 1);
-        }
-        return name;
-    }
-
-    export function startsWithQuote(name: string): boolean {
-        return isSingleOrDoubleQuote(name.charCodeAt(0));
-    }
-
     export function scriptKindIs(fileName: string, host: LanguageServiceHost, ...scriptKinds: ScriptKind[]): boolean {
         const scriptKind = getScriptKind(fileName, host);
         return some(scriptKinds, k => k === scriptKind);
@@ -1751,8 +1735,8 @@ namespace ts {
 
     function getSynthesizedDeepCloneWorker<T extends Node>(node: T, renameMap?: Map<Identifier>, checker?: TypeChecker, callback?: (originalNode: Node, clone: Node) => any): T {
         const visited = (renameMap || checker || callback) ?
-        visitEachChild(node, wrapper, nullTransformationContext) :
-        visitEachChild(node, getSynthesizedDeepClone, nullTransformationContext);
+            visitEachChild(node, wrapper, nullTransformationContext) :
+            visitEachChild(node, getSynthesizedDeepClone, nullTransformationContext);
 
         if (visited === node) {
             // This only happens for leaf nodes - internal nodes always see their children change.
@@ -2038,53 +2022,4 @@ namespace ts {
         // If even 2/5 places have a semicolon, the user probably wants semicolons
         return withSemicolon / withoutSemicolon > 1 / nStatementsToObserve;
     }
-
-    export function tryGetDirectories(host: LanguageServiceHost, directoryName: string): string[] {
-        return tryIOAndConsumeErrors(host, host.getDirectories, directoryName) || [];
-    }
-
-    export function tryReadDirectory(host: LanguageServiceHost, path: string, extensions?: ReadonlyArray<string>, exclude?: ReadonlyArray<string>, include?: ReadonlyArray<string>): ReadonlyArray<string> {
-        return tryIOAndConsumeErrors(host, host.readDirectory, path, extensions, exclude, include) || emptyArray;
-    }
-
-    export function tryFileExists(host: LanguageServiceHost, path: string): boolean {
-        return tryIOAndConsumeErrors(host, host.fileExists, path);
-    }
-
-    export function tryDirectoryExists(host: LanguageServiceHost, path: string): boolean {
-        return tryAndIgnoreErrors(() => directoryProbablyExists(path, host)) || false;
-    }
-
-    export function tryAndIgnoreErrors<T>(cb: () => T): T | undefined {
-        try { return cb(); }
-        catch { return undefined; }
-    }
-
-    export function tryIOAndConsumeErrors<T>(host: LanguageServiceHost, toApply: ((...a: any[]) => T) | undefined, ...args: any[]) {
-        return tryAndIgnoreErrors(() => toApply && toApply.apply(host, args));
-    }
-
-    export function findPackageJsons(directory: string, host: LanguageServiceHost): string[] {
-        const paths: string[] = [];
-        forEachAncestorDirectory(directory, ancestor => {
-            const currentConfigPath = findConfigFile(ancestor, (f) => tryFileExists(host, f), "package.json");
-            if (!currentConfigPath) {
-                return true; // break out
-            }
-            paths.push(currentConfigPath);
-        });
-        return paths;
-    }
-
-    export function findPackageJson(directory: string, host: LanguageServiceHost): string | undefined {
-        let packageJson: string | undefined;
-        forEachAncestorDirectory(directory, ancestor => {
-            if (ancestor === "node_modules") return true;
-            packageJson = findConfigFile(ancestor, (f) => tryFileExists(host, f), "package.json");
-            if (packageJson) {
-                return true; // break out
-            }
-        });
-        return packageJson;
-    }
 }

src/testRunner/tsconfig.json

@@ -73,7 +73,9 @@
         "unittests/config/tsconfigParsing.ts",
         "unittests/evaluation/asyncArrow.ts",
         "unittests/evaluation/asyncGenerator.ts",
+        "unittests/evaluation/awaiter.ts",
         "unittests/evaluation/forAwaitOf.ts",
+        "unittests/evaluation/objectRest.ts",
         "unittests/services/cancellableLanguageServiceOperations.ts",
         "unittests/services/colorization.ts",
         "unittests/services/convertToAsyncFunction.ts",

src/testRunner/unittests/evaluation/awaiter.ts

@@ -0,0 +1,24 @@
+describe("unittests:: evaluation:: awaiter", () => {
+    // NOTE: This could break if the ECMAScript spec ever changes the timing behavior for Promises (again)
+    it("await (es5)", async () => {
+        const result = evaluator.evaluateTypeScript(`
+        async function a(msg: string) {
+            await Promise.resolve();
+            output.push(msg);
+        }
+        function b(msg: string) {
+            return Promise.resolve().then(() => {
+                output.push(msg);
+            });
+        }
+        export const output: string[] = [];
+        export async function main() {
+            const p1 = a('1');
+            const p2 = b('2');
+            await Promise.all([p1, p2]);
+        }
+        `);
+        await result.main();
+        assert.deepEqual(result.output, ["1", "2"]);
+    });
+});

src/testRunner/unittests/evaluation/objectRest.ts

@@ -0,0 +1,28 @@
+describe("unittests:: evaluation:: objectRest", () => {
+    // https://github.com/microsoft/TypeScript/issues/31469
+    it("side effects in property assignment", async () => {
+        const result = evaluator.evaluateTypeScript(`
+            const k = { a: 1, b: 2 };
+            const o = { a: 3, ...k, b: k.a++ };
+            export const output = o;
+        `);
+        assert.deepEqual(result.output, { a: 1, b: 1 });
+    });
+    it("side effects in during spread", async () => {
+        const result = evaluator.evaluateTypeScript(`
+            const k = { a: 1, get b() { l = { c: 9 }; return 2; } };
+            let l = { c: 3 };
+            const o = { ...k, ...l };
+            export const output = o;
+        `);
+        assert.deepEqual(result.output, { a: 1, b: 2, c: 9 });
+    });
+    it("trailing literal-valued object-literal", async () => {
+        const result = evaluator.evaluateTypeScript(`
+            const k = { a: 1 }
+            const o = { ...k, ...{ b: 2 } };
+            export const output = o;
+        `);
+        assert.deepEqual(result.output, { a: 1, b: 2 });
+    });
+});

src/testRunner/unittests/publicApi.ts

@@ -31,3 +31,18 @@ describe("Public APIs", () => {
         verifyApi("tsserverlibrary.d.ts");
     });
 });
+
+describe("Public APIs:: token to string", () => {
+    function assertDefinedTokenToString(initial: ts.SyntaxKind, last: ts.SyntaxKind) {
+        for (let t = initial; t <= last; t++) {
+            assert.isDefined(ts.tokenToString(t), `Expected tokenToString defined for ${ts.Debug.formatSyntaxKind(t)}`);
+        }
+    }
+
+    it("for punctuations", () => {
+        assertDefinedTokenToString(ts.SyntaxKind.FirstPunctuation, ts.SyntaxKind.LastPunctuation);
+    });
+    it("for keywords", () => {
+        assertDefinedTokenToString(ts.SyntaxKind.FirstKeyword, ts.SyntaxKind.LastKeyword);
+    });
+});

src/testRunner/unittests/tsserver/projects.ts

@@ -1467,5 +1467,22 @@ var x = 10;`
                 openFilesForSession([{ file, projectRootPath }], session);
             }
         });
+
+        it("assert when removing project", () => {
+            const host = createServerHost([commonFile1, commonFile2, libFile]);
+            const service = createProjectService(host);
+            service.openClientFile(commonFile1.path);
+            const project = service.inferredProjects[0];
+            checkProjectActualFiles(project, [commonFile1.path, libFile.path]);
+            // Intentionally create scriptinfo and attach it to project
+            const info = service.getOrCreateScriptInfoForNormalizedPath(commonFile2.path as server.NormalizedPath, /*openedByClient*/ false)!;
+            info.attachToProject(project);
+            try {
+                service.applyChangesInOpenFiles(/*openFiles*/ undefined, /*changedFiles*/ undefined, [commonFile1.path]);
+            }
+            catch (e) {
+                assert.isTrue(e.message.indexOf("Debug Failure. False expression: Found script Info still attached to project") === 0);
+            }
+        });
     });
 }

src/testRunner/unittests/tsserver/typingsInstaller.ts

@@ -1,6 +1,6 @@
 namespace ts.projectSystem {
     import validatePackageName = JsTyping.validatePackageName;
-    import PackageNameValidationResult = JsTyping.PackageNameValidationResult;
+    import NameValidationResult = JsTyping.NameValidationResult;
 
     interface InstallerParams {
         globalTypingsCacheLocation?: string;
@@ -948,7 +948,8 @@ namespace ts.projectSystem {
                 path: "/a/b/app.js",
                 content: `
                 import * as fs from "fs";
-                import * as commander from "commander";`
+                import * as commander from "commander";
+                import * as component from "@ember/component";`
             };
             const cachePath = "/a/cache";
             const node = {
@@ -959,14 +960,19 @@ namespace ts.projectSystem {
                 path: cachePath + "/node_modules/@types/commander/index.d.ts",
                 content: "export let y: string"
             };
+            const emberComponentDirectory = "ember__component";
+            const emberComponent = {
+                path: `${cachePath}/node_modules/@types/${emberComponentDirectory}/index.d.ts`,
+                content: "export let x: number"
+            };
             const host = createServerHost([file]);
             const installer = new (class extends Installer {
                 constructor() {
                     super(host, { globalTypingsCacheLocation: cachePath, typesRegistry: createTypesRegistry("node", "commander") });
                 }
                 installWorker(_requestId: number, _args: string[], _cwd: string, cb: TI.RequestCompletedAction) {
-                    const installedTypings = ["@types/node", "@types/commander"];
-                    const typingFiles = [node, commander];
+                    const installedTypings = ["@types/node", "@types/commander", `@types/${emberComponentDirectory}`];
+                    const typingFiles = [node, commander, emberComponent];
                     executeCommand(this, host, installedTypings, typingFiles, cb);
                 }
             })();
@@ -980,9 +986,10 @@ namespace ts.projectSystem {
 
             assert.isTrue(host.fileExists(node.path), "typings for 'node' should be created");
             assert.isTrue(host.fileExists(commander.path), "typings for 'commander' should be created");
+            assert.isTrue(host.fileExists(emberComponent.path), "typings for 'commander' should be created");
 
             host.checkTimeoutQueueLengthAndRun(2);
-            checkProjectActualFiles(service.inferredProjects[0], [file.path, node.path, commander.path]);
+            checkProjectActualFiles(service.inferredProjects[0], [file.path, node.path, commander.path, emberComponent.path]);
         });
 
         it("should redo resolution that resolved to '.js' file after typings are installed", () => {
@@ -1263,21 +1270,44 @@ namespace ts.projectSystem {
             for (let i = 0; i < 8; i++) {
                 packageName += packageName;
             }
-            assert.equal(validatePackageName(packageName), PackageNameValidationResult.NameTooLong);
+            assert.equal(validatePackageName(packageName), NameValidationResult.NameTooLong);
         });
-        it("name cannot start with dot", () => {
-            assert.equal(validatePackageName(".foo"), PackageNameValidationResult.NameStartsWithDot);
+        it("package name cannot start with dot", () => {
+            assert.equal(validatePackageName(".foo"), NameValidationResult.NameStartsWithDot);
         });
-        it("name cannot start with underscore", () => {
-            assert.equal(validatePackageName("_foo"), PackageNameValidationResult.NameStartsWithUnderscore);
+        it("package name cannot start with underscore", () => {
+            assert.equal(validatePackageName("_foo"), NameValidationResult.NameStartsWithUnderscore);
         });
-        it("scoped packages not supported", () => {
-            assert.equal(validatePackageName("@scope/bar"), PackageNameValidationResult.ScopedPackagesNotSupported);
+        it("package non URI safe characters are not supported", () => {
+            assert.equal(validatePackageName("  scope  "), NameValidationResult.NameContainsNonURISafeCharacters);
+            assert.equal(validatePackageName("; say ‘Hello from TypeScript!’ #"), NameValidationResult.NameContainsNonURISafeCharacters);
+            assert.equal(validatePackageName("a/b/c"), NameValidationResult.NameContainsNonURISafeCharacters);
         });
-        it("non URI safe characters are not supported", () => {
-            assert.equal(validatePackageName("  scope  "), PackageNameValidationResult.NameContainsNonURISafeCharacters);
-            assert.equal(validatePackageName("; say ‘Hello from TypeScript!’ #"), PackageNameValidationResult.NameContainsNonURISafeCharacters);
-            assert.equal(validatePackageName("a/b/c"), PackageNameValidationResult.NameContainsNonURISafeCharacters);
+        it("scoped package name is supported", () => {
+            assert.equal(validatePackageName("@scope/bar"), NameValidationResult.Ok);
+        });
+        it("scoped name in scoped package name cannot start with dot", () => {
+            assert.deepEqual(validatePackageName("@.scope/bar"), { name: ".scope", isScopeName: true, result: NameValidationResult.NameStartsWithDot });
+            assert.deepEqual(validatePackageName("@.scope/.bar"), { name: ".scope", isScopeName: true, result: NameValidationResult.NameStartsWithDot });
+        });
+        it("scope name in scoped package name cannot start with underscore", () => {
+            assert.deepEqual(validatePackageName("@_scope/bar"), { name: "_scope", isScopeName: true, result: NameValidationResult.NameStartsWithUnderscore });
+            assert.deepEqual(validatePackageName("@_scope/_bar"), { name: "_scope", isScopeName: true, result: NameValidationResult.NameStartsWithUnderscore });
+        });
+        it("scope name in scoped package name with non URI safe characters are not supported", () => {
+            assert.deepEqual(validatePackageName("@  scope  /bar"), { name: "  scope  ", isScopeName: true, result: NameValidationResult.NameContainsNonURISafeCharacters });
+            assert.deepEqual(validatePackageName("@; say ‘Hello from TypeScript!’ #/bar"), { name: "; say ‘Hello from TypeScript!’ #", isScopeName: true, result: NameValidationResult.NameContainsNonURISafeCharacters });
+            assert.deepEqual(validatePackageName("@  scope  /  bar  "), { name: "  scope  ", isScopeName: true, result: NameValidationResult.NameContainsNonURISafeCharacters });
+        });
+        it("package name in scoped package name cannot start with dot", () => {
+            assert.deepEqual(validatePackageName("@scope/.bar"), { name: ".bar", isScopeName: false, result: NameValidationResult.NameStartsWithDot });
+        });
+        it("package name in scoped package name cannot start with underscore", () => {
+            assert.deepEqual(validatePackageName("@scope/_bar"), { name: "_bar", isScopeName: false, result: NameValidationResult.NameStartsWithUnderscore });
+        });
+        it("package name in scoped package name with non URI safe characters are not supported", () => {
+            assert.deepEqual(validatePackageName("@scope/  bar  "), { name: "  bar  ", isScopeName: false, result: NameValidationResult.NameContainsNonURISafeCharacters });
+            assert.deepEqual(validatePackageName("@scope/; say ‘Hello from TypeScript!’ #"), { name: "; say ‘Hello from TypeScript!’ #", isScopeName: false, result: NameValidationResult.NameContainsNonURISafeCharacters });
         });
     });
 
@@ -1309,7 +1339,7 @@ namespace ts.projectSystem {
             projectService.openClientFile(f1.path);
 
             installer.checkPendingCommands(/*expectedCount*/ 0);
-            assert.isTrue(messages.indexOf("Package name '; say ‘Hello from TypeScript!’ #' contains non URI safe characters") > 0, "should find package with invalid name");
+            assert.isTrue(messages.indexOf("'; say ‘Hello from TypeScript!’ #':: Package name '; say ‘Hello from TypeScript!’ #' contains non URI safe characters") > 0, "should find package with invalid name");
         });
     });
 

src/tsserver/server.ts

@@ -248,7 +248,7 @@ namespace ts.server {
         isKnownTypesPackageName(name: string): boolean {
             // We want to avoid looking this up in the registry as that is expensive. So first check that it's actually an NPM package.
             const validationResult = JsTyping.validatePackageName(name);
-            if (validationResult !== JsTyping.PackageNameValidationResult.Ok) {
+            if (validationResult !== JsTyping.NameValidationResult.Ok) {
                 return false;
             }
 

src/typingsInstallerCore/typingsInstaller.ts

@@ -268,27 +268,28 @@ namespace ts.server.typingsInstaller {
         }
 
         private filterTypings(typingsToInstall: ReadonlyArray<string>): ReadonlyArray<string> {
-            return typingsToInstall.filter(typing => {
-                if (this.missingTypingsSet.get(typing)) {
-                    if (this.log.isEnabled()) this.log.writeLine(`'${typing}' is in missingTypingsSet - skipping...`);
-                    return false;
+            return mapDefined(typingsToInstall, typing => {
+                const typingKey = mangleScopedPackageName(typing);
+                if (this.missingTypingsSet.get(typingKey)) {
+                    if (this.log.isEnabled()) this.log.writeLine(`'${typing}':: '${typingKey}' is in missingTypingsSet - skipping...`);
+                    return undefined;
                 }
                 const validationResult = JsTyping.validatePackageName(typing);
-                if (validationResult !== JsTyping.PackageNameValidationResult.Ok) {
+                if (validationResult !== JsTyping.NameValidationResult.Ok) {
                     // add typing name to missing set so we won't process it again
-                    this.missingTypingsSet.set(typing, true);
+                    this.missingTypingsSet.set(typingKey, true);
                     if (this.log.isEnabled()) this.log.writeLine(JsTyping.renderPackageNameValidationFailure(validationResult, typing));
-                    return false;
+                    return undefined;
                 }
-                if (!this.typesRegistry.has(typing)) {
-                    if (this.log.isEnabled()) this.log.writeLine(`Entry for package '${typing}' does not exist in local types registry - skipping...`);
-                    return false;
+                if (!this.typesRegistry.has(typingKey)) {
+                    if (this.log.isEnabled()) this.log.writeLine(`'${typing}':: Entry for package '${typingKey}' does not exist in local types registry - skipping...`);
+                    return undefined;
                 }
-                if (this.packageNameToTypingLocation.get(typing) && JsTyping.isTypingUpToDate(this.packageNameToTypingLocation.get(typing)!, this.typesRegistry.get(typing)!)) {
-                    if (this.log.isEnabled()) this.log.writeLine(`'${typing}' already has an up-to-date typing - skipping...`);
-                    return false;
+                if (this.packageNameToTypingLocation.get(typingKey) && JsTyping.isTypingUpToDate(this.packageNameToTypingLocation.get(typingKey)!, this.typesRegistry.get(typingKey)!)) {
+                    if (this.log.isEnabled()) this.log.writeLine(`'${typing}':: '${typingKey}' already has an up-to-date typing - skipping...`);
+                    return undefined;
                 }
-                return true;
+                return typingKey;
             });
         }
 

tests/baselines/reference/api/tsserverlibrary.d.ts

@@ -1155,6 +1155,7 @@ declare namespace ts {
         expression: JsxTagNameExpression;
     }
     interface JsxAttributes extends ObjectLiteralExpressionBase<JsxAttributeLike> {
+        kind: SyntaxKind.JsxAttributes;
         parent: JsxOpeningLikeElement;
     }
     interface JsxOpeningElement extends Expression {
@@ -2599,7 +2600,7 @@ declare namespace ts {
         UMD = 3,
         System = 4,
         ES2015 = 5,
-        ESNext = 6
+        ESNext = 99
     }
     enum JsxEmit {
         None = 0,
@@ -2639,9 +2640,9 @@ declare namespace ts {
         ES2018 = 5,
         ES2019 = 6,
         ES2020 = 7,
-        ESNext = 8,
+        ESNext = 99,
         JSON = 100,
-        Latest = 8
+        Latest = 99
     }
     enum LanguageVariant {
         Standard = 0,
@@ -5403,7 +5404,7 @@ declare namespace ts {
         argumentCount: number;
     }
     interface CompletionInfo {
-        /** Not true for all glboal completions. This will be true if the enclosing scope matches a few syntax kinds. See `isSnippetScope`. */
+        /** Not true for all global completions. This will be true if the enclosing scope matches a few syntax kinds. See `isSnippetScope`. */
         isGlobalCompletion: boolean;
         isMemberCompletion: boolean;
         /**

tests/baselines/reference/api/typescript.d.ts

@@ -1155,6 +1155,7 @@ declare namespace ts {
         expression: JsxTagNameExpression;
     }
     interface JsxAttributes extends ObjectLiteralExpressionBase<JsxAttributeLike> {
+        kind: SyntaxKind.JsxAttributes;
         parent: JsxOpeningLikeElement;
     }
     interface JsxOpeningElement extends Expression {
@@ -2599,7 +2600,7 @@ declare namespace ts {
         UMD = 3,
         System = 4,
         ES2015 = 5,
-        ESNext = 6
+        ESNext = 99
     }
     enum JsxEmit {
         None = 0,
@@ -2639,9 +2640,9 @@ declare namespace ts {
         ES2018 = 5,
         ES2019 = 6,
         ES2020 = 7,
-        ESNext = 8,
+        ESNext = 99,
         JSON = 100,
-        Latest = 8
+        Latest = 99
     }
     enum LanguageVariant {
         Standard = 0,
@@ -5403,7 +5404,7 @@ declare namespace ts {
         argumentCount: number;
     }
     interface CompletionInfo {
-        /** Not true for all glboal completions. This will be true if the enclosing scope matches a few syntax kinds. See `isSnippetScope`. */
+        /** Not true for all global completions. This will be true if the enclosing scope matches a few syntax kinds. See `isSnippetScope`. */
         isGlobalCompletion: boolean;
         isMemberCompletion: boolean;
         /**

tests/baselines/reference/asyncArrowFunction11_es5.js

@@ -9,10 +9,11 @@ class A {
 
 //// [asyncArrowFunction11_es5.js]
 var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
     return new (P || (P = Promise))(function (resolve, reject) {
         function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
         function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
-        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
         step((generator = generator.apply(thisArg, _arguments || [])).next());
     });
 };

tests/baselines/reference/asyncAwaitIsolatedModules_es5.js

@@ -42,10 +42,11 @@ module M {
 //// [asyncAwaitIsolatedModules_es5.js]
 "use strict";
 var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
     return new (P || (P = Promise))(function (resolve, reject) {
         function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
         function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
-        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
         step((generator = generator.apply(thisArg, _arguments || [])).next());
     });
 };

tests/baselines/reference/asyncAwaitIsolatedModules_es6.js

@@ -41,10 +41,11 @@ module M {
 
 //// [asyncAwaitIsolatedModules_es6.js]
 var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
     return new (P || (P = Promise))(function (resolve, reject) {
         function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
         function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
-        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
         step((generator = generator.apply(thisArg, _arguments || [])).next());
     });
 };

tests/baselines/reference/asyncAwait_es5.js

@@ -48,10 +48,11 @@ async function f14() {
 
 //// [asyncAwait_es5.js]
 var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
     return new (P || (P = Promise))(function (resolve, reject) {
         function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
         function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
-        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
         step((generator = generator.apply(thisArg, _arguments || [])).next());
     });
 };

tests/baselines/reference/asyncAwait_es6.js

@@ -48,10 +48,11 @@ async function f14() {
 
 //// [asyncAwait_es6.js]
 var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
     return new (P || (P = Promise))(function (resolve, reject) {
         function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
         function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
-        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
         step((generator = generator.apply(thisArg, _arguments || [])).next());
     });
 };

tests/baselines/reference/asyncFunctionNoReturnType.js

@@ -7,10 +7,11 @@ async () => {
 
 //// [asyncFunctionNoReturnType.js]
 var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
     return new (P || (P = Promise))(function (resolve, reject) {
         function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
         function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
-        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
         step((generator = generator.apply(thisArg, _arguments || [])).next());
     });
 };

tests/baselines/reference/asyncFunctionReturnExpressionErrorSpans.js

@@ -23,10 +23,11 @@ async function asyncFoo(): Promise<Foo> {
 
 //// [asyncFunctionReturnExpressionErrorSpans.js]
 var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
     return new (P || (P = Promise))(function (resolve, reject) {
         function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
         function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
-        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
         step((generator = generator.apply(thisArg, _arguments || [])).next());
     });
 };

tests/baselines/reference/asyncFunctionReturnType.js

@@ -77,10 +77,11 @@ async function fGenericIndexedTypeForExplicitPromiseOfKProp<TObj extends Obj, K
 
 //// [asyncFunctionReturnType.js]
 var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
     return new (P || (P = Promise))(function (resolve, reject) {
         function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
         function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
-        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
         step((generator = generator.apply(thisArg, _arguments || [])).next());
     });
 };

tests/baselines/reference/asyncFunctionTempVariableScoping.js

@@ -6,10 +6,11 @@ async ({ foo, bar, ...rest }) => bar(await foo);
 //// [asyncFunctionTempVariableScoping.js]
 // https://github.com/Microsoft/TypeScript/issues/19187
 var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
     return new (P || (P = Promise))(function (resolve, reject) {
         function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
         function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
-        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
         step((generator = generator.apply(thisArg, _arguments || [])).next());
     });
 };

tests/baselines/reference/asyncFunctionWithForStatementNoInitializer.js

@@ -26,10 +26,11 @@ async function test4() {
 
 //// [asyncFunctionWithForStatementNoInitializer.js]
 var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
     return new (P || (P = Promise))(function (resolve, reject) {
         function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
         function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
-        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
         step((generator = generator.apply(thisArg, _arguments || [])).next());
     });
 };

tests/baselines/reference/asyncFunctionsAcrossFiles.js

@@ -17,10 +17,11 @@ export const b = {
 
 //// [b.js]
 var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
     return new (P || (P = Promise))(function (resolve, reject) {
         function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
         function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
-        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
         step((generator = generator.apply(thisArg, _arguments || [])).next());
     });
 };
@@ -32,10 +33,11 @@ export const b = {
 };
 //// [a.js]
 var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
     return new (P || (P = Promise))(function (resolve, reject) {
         function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
         function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
-        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
         step((generator = generator.apply(thisArg, _arguments || [])).next());
     });
 };

tests/baselines/reference/asyncFunctionsAndStrictNullChecks.js

@@ -27,10 +27,11 @@ async function sample2(x?: number) {
 
 //// [asyncFunctionsAndStrictNullChecks.js]
 var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
     return new (P || (P = Promise))(function (resolve, reject) {
         function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
         function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
-        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
         step((generator = generator.apply(thisArg, _arguments || [])).next());
     });
 };

tests/baselines/reference/asyncIIFE.js

@@ -11,10 +11,11 @@ function f1() {
 
 //// [asyncIIFE.js]
 var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
     return new (P || (P = Promise))(function (resolve, reject) {
         function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
         function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
-        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
         step((generator = generator.apply(thisArg, _arguments || [])).next());
     });
 };

tests/baselines/reference/asyncImportedPromise_es5.js

@@ -36,10 +36,11 @@ exports.Task = Task;
 //// [test.js]
 "use strict";
 var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
     return new (P || (P = Promise))(function (resolve, reject) {
         function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
         function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
-        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
         step((generator = generator.apply(thisArg, _arguments || [])).next());
     });
 };

tests/baselines/reference/asyncImportedPromise_es6.js

@@ -18,10 +18,11 @@ exports.Task = Task;
 //// [test.js]
 "use strict";
 var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
     return new (P || (P = Promise))(function (resolve, reject) {
         function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
         function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
-        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
         step((generator = generator.apply(thisArg, _arguments || [])).next());
     });
 };

tests/baselines/reference/asyncMethodWithSuperConflict_es6.js

@@ -61,10 +61,11 @@ class B extends A {
 
 //// [asyncMethodWithSuperConflict_es6.js]
 var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
     return new (P || (P = Promise))(function (resolve, reject) {
         function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
         function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
-        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
         step((generator = generator.apply(thisArg, _arguments || [])).next());
     });
 };

tests/baselines/reference/asyncMultiFile_es5.js

@@ -7,10 +7,11 @@ function g() { }
 
 //// [a.js]
 var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
     return new (P || (P = Promise))(function (resolve, reject) {
         function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
         function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
-        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
         step((generator = generator.apply(thisArg, _arguments || [])).next());
     });
 };

tests/baselines/reference/asyncMultiFile_es6.js

@@ -7,10 +7,11 @@ function g() { }
 
 //// [a.js]
 var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
     return new (P || (P = Promise))(function (resolve, reject) {
         function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
         function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
-        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
         step((generator = generator.apply(thisArg, _arguments || [])).next());
     });
 };

tests/baselines/reference/awaitUnionPromise.js

@@ -23,10 +23,11 @@ async function main() {
 /// @target: es2015
 // https://github.com/Microsoft/TypeScript/issues/18186
 var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
     return new (P || (P = Promise))(function (resolve, reject) {
         function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
         function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
-        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
         step((generator = generator.apply(thisArg, _arguments || [])).next());
     });
 };

tests/baselines/reference/await_unaryExpression_es6.js

@@ -17,10 +17,11 @@ async function bar4() {
 
 //// [await_unaryExpression_es6.js]
 var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
     return new (P || (P = Promise))(function (resolve, reject) {
         function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
         function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
-        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
         step((generator = generator.apply(thisArg, _arguments || [])).next());
     });
 };

tests/baselines/reference/await_unaryExpression_es6_1.js

@@ -21,10 +21,11 @@ async function bar4() {
 
 //// [await_unaryExpression_es6_1.js]
 var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
     return new (P || (P = Promise))(function (resolve, reject) {
         function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
         function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
-        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
         step((generator = generator.apply(thisArg, _arguments || [])).next());
     });
 };

tests/baselines/reference/await_unaryExpression_es6_2.js

@@ -13,10 +13,11 @@ async function bar3() {
 
 //// [await_unaryExpression_es6_2.js]
 var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
     return new (P || (P = Promise))(function (resolve, reject) {
         function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
         function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
-        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
         step((generator = generator.apply(thisArg, _arguments || [])).next());
     });
 };

tests/baselines/reference/await_unaryExpression_es6_3.js

@@ -19,10 +19,11 @@ async function bar4() {
 
 //// [await_unaryExpression_es6_3.js]
 var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
     return new (P || (P = Promise))(function (resolve, reject) {
         function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
         function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
-        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
         step((generator = generator.apply(thisArg, _arguments || [])).next());
     });
 };

tests/baselines/reference/capturedParametersInInitializers1.js

@@ -42,10 +42,11 @@ function foo9(y = {[z]() { return z; }}, z = 1) {
 
 //// [capturedParametersInInitializers1.js]
 var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
     return new (P || (P = Promise))(function (resolve, reject) {
         function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
         function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
-        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
         step((generator = generator.apply(thisArg, _arguments || [])).next());
     });
 };

tests/baselines/reference/castOfAwait.js

@@ -10,10 +10,11 @@ async function f() {
 
 //// [castOfAwait.js]
 var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
     return new (P || (P = Promise))(function (resolve, reject) {
         function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
         function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
-        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
         step((generator = generator.apply(thisArg, _arguments || [])).next());
     });
 };

tests/baselines/reference/castOfYield.errors.txt

@@ -1,8 +1,8 @@
-error TS2318: Cannot find global type 'Generator'.
+error TS2318: Cannot find global type 'IterableIterator'.
 tests/cases/compiler/castOfYield.ts(4,14): error TS1109: Expression expected.
 
 
-!!! error TS2318: Cannot find global type 'Generator'.
+!!! error TS2318: Cannot find global type 'IterableIterator'.
 ==== tests/cases/compiler/castOfYield.ts (1 errors) ====
     function* f() {
         <number> (yield 0);

tests/baselines/reference/checkJsxSubtleSkipContextSensitiveBug.js

@@ -40,10 +40,11 @@ var __extends = (this && this.__extends) || (function () {
     };
 })();
 var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
     return new (P || (P = Promise))(function (resolve, reject) {
         function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
         function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
-        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
         step((generator = generator.apply(thisArg, _arguments || [])).next());
     });
 };

tests/baselines/reference/circularInferredTypeOfVariable.js

@@ -21,10 +21,11 @@
 //// [circularInferredTypeOfVariable.js]
 // Repro from #14428
 var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
     return new (P || (P = Promise))(function (resolve, reject) {
         function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
         function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
-        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
         step((generator = generator.apply(thisArg, _arguments || [])).next());
     });
 };

tests/baselines/reference/controlFlowElementAccess2.js

@@ -0,0 +1,25 @@
+//// [controlFlowElementAccess2.ts]
+declare const config: {
+    [key: string]: boolean | { prop: string };
+};
+
+if (typeof config['works'] !== 'boolean') {
+    config.works.prop = 'test'; // ok
+    config['works'].prop = 'test'; // error, config['works']: boolean | { 'prop': string }
+}
+if (typeof config.works !== 'boolean') {
+    config['works'].prop = 'test'; // error, config['works']: boolean | { 'prop': string }
+    config.works.prop = 'test'; // ok
+}
+
+
+//// [controlFlowElementAccess2.js]
+"use strict";
+if (typeof config['works'] !== 'boolean') {
+    config.works.prop = 'test'; // ok
+    config['works'].prop = 'test'; // error, config['works']: boolean | { 'prop': string }
+}
+if (typeof config.works !== 'boolean') {
+    config['works'].prop = 'test'; // error, config['works']: boolean | { 'prop': string }
+    config.works.prop = 'test'; // ok
+}

tests/baselines/reference/controlFlowElementAccess2.symbols

@@ -0,0 +1,37 @@
+=== tests/cases/conformance/controlFlow/controlFlowElementAccess2.ts ===
+declare const config: {
+>config : Symbol(config, Decl(controlFlowElementAccess2.ts, 0, 13))
+
+    [key: string]: boolean | { prop: string };
+>key : Symbol(key, Decl(controlFlowElementAccess2.ts, 1, 5))
+>prop : Symbol(prop, Decl(controlFlowElementAccess2.ts, 1, 30))
+
+};
+
+if (typeof config['works'] !== 'boolean') {
+>config : Symbol(config, Decl(controlFlowElementAccess2.ts, 0, 13))
+
+    config.works.prop = 'test'; // ok
+>config.works.prop : Symbol(prop, Decl(controlFlowElementAccess2.ts, 1, 30))
+>config : Symbol(config, Decl(controlFlowElementAccess2.ts, 0, 13))
+>prop : Symbol(prop, Decl(controlFlowElementAccess2.ts, 1, 30))
+
+    config['works'].prop = 'test'; // error, config['works']: boolean | { 'prop': string }
+>config['works'].prop : Symbol(prop, Decl(controlFlowElementAccess2.ts, 1, 30))
+>config : Symbol(config, Decl(controlFlowElementAccess2.ts, 0, 13))
+>prop : Symbol(prop, Decl(controlFlowElementAccess2.ts, 1, 30))
+}
+if (typeof config.works !== 'boolean') {
+>config : Symbol(config, Decl(controlFlowElementAccess2.ts, 0, 13))
+
+    config['works'].prop = 'test'; // error, config['works']: boolean | { 'prop': string }
+>config['works'].prop : Symbol(prop, Decl(controlFlowElementAccess2.ts, 1, 30))
+>config : Symbol(config, Decl(controlFlowElementAccess2.ts, 0, 13))
+>prop : Symbol(prop, Decl(controlFlowElementAccess2.ts, 1, 30))
+
+    config.works.prop = 'test'; // ok
+>config.works.prop : Symbol(prop, Decl(controlFlowElementAccess2.ts, 1, 30))
+>config : Symbol(config, Decl(controlFlowElementAccess2.ts, 0, 13))
+>prop : Symbol(prop, Decl(controlFlowElementAccess2.ts, 1, 30))
+}
+

tests/baselines/reference/controlFlowElementAccess2.types

@@ -0,0 +1,63 @@
+=== tests/cases/conformance/controlFlow/controlFlowElementAccess2.ts ===
+declare const config: {
+>config : { [key: string]: boolean | { prop: string; }; }
+
+    [key: string]: boolean | { prop: string };
+>key : string
+>prop : string
+
+};
+
+if (typeof config['works'] !== 'boolean') {
+>typeof config['works'] !== 'boolean' : boolean
+>typeof config['works'] : "string" | "number" | "bigint" | "boolean" | "symbol" | "undefined" | "object" | "function"
+>config['works'] : boolean | { prop: string; }
+>config : { [key: string]: boolean | { prop: string; }; }
+>'works' : "works"
+>'boolean' : "boolean"
+
+    config.works.prop = 'test'; // ok
+>config.works.prop = 'test' : "test"
+>config.works.prop : string
+>config.works : { prop: string; }
+>config : { [key: string]: boolean | { prop: string; }; }
+>works : { prop: string; }
+>prop : string
+>'test' : "test"
+
+    config['works'].prop = 'test'; // error, config['works']: boolean | { 'prop': string }
+>config['works'].prop = 'test' : "test"
+>config['works'].prop : string
+>config['works'] : { prop: string; }
+>config : { [key: string]: boolean | { prop: string; }; }
+>'works' : "works"
+>prop : string
+>'test' : "test"
+}
+if (typeof config.works !== 'boolean') {
+>typeof config.works !== 'boolean' : boolean
+>typeof config.works : "string" | "number" | "bigint" | "boolean" | "symbol" | "undefined" | "object" | "function"
+>config.works : boolean | { prop: string; }
+>config : { [key: string]: boolean | { prop: string; }; }
+>works : boolean | { prop: string; }
+>'boolean' : "boolean"
+
+    config['works'].prop = 'test'; // error, config['works']: boolean | { 'prop': string }
+>config['works'].prop = 'test' : "test"
+>config['works'].prop : string
+>config['works'] : { prop: string; }
+>config : { [key: string]: boolean | { prop: string; }; }
+>'works' : "works"
+>prop : string
+>'test' : "test"
+
+    config.works.prop = 'test'; // ok
+>config.works.prop = 'test' : "test"
+>config.works.prop : string
+>config.works : { prop: string; }
+>config : { [key: string]: boolean | { prop: string; }; }
+>works : { prop: string; }
+>prop : string
+>'test' : "test"
+}
+

tests/baselines/reference/controlFlowForCatchAndFinally.js

@@ -43,10 +43,11 @@ class Foo {
 //// [controlFlowForCatchAndFinally.js]
 "use strict";
 var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
     return new (P || (P = Promise))(function (resolve, reject) {
         function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
         function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
-        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
         step((generator = generator.apply(thisArg, _arguments || [])).next());
     });
 };

tests/baselines/reference/correctOrderOfPromiseMethod.js

@@ -27,10 +27,11 @@ async function countEverything(): Promise<number> {
 
 //// [correctOrderOfPromiseMethod.js]
 var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
     return new (P || (P = Promise))(function (resolve, reject) {
         function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
         function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
-        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
         step((generator = generator.apply(thisArg, _arguments || [])).next());
     });
 };

tests/baselines/reference/declarationEmitPrivateAsync.js

@@ -8,10 +8,11 @@ export class Foo {
 //// [declarationEmitPrivateAsync.js]
 "use strict";
 var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
     return new (P || (P = Promise))(function (resolve, reject) {
         function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
         function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
-        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
         step((generator = generator.apply(thisArg, _arguments || [])).next());
     });
 };

tests/baselines/reference/declarationEmitPromise.js

@@ -24,10 +24,11 @@ export async function runSampleBreaks<A, B, C, D, E>(
 //// [declarationEmitPromise.js]
 "use strict";
 var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
     return new (P || (P = Promise))(function (resolve, reject) {
         function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
         function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
-        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
         step((generator = generator.apply(thisArg, _arguments || [])).next());
     });
 };

tests/baselines/reference/declarationsWithRecursiveInternalTypesProduceUniqueTypeParams.js

@@ -73,7 +73,7 @@ exports.testRecFun = function (parent) {
     return {
         result: parent,
         deeper: function (child) {
-            return exports.testRecFun(__assign({}, parent, child));
+            return exports.testRecFun(__assign(__assign({}, parent), child));
         }
     };
 };

tests/baselines/reference/decoratorMetadataPromise.js

@@ -22,10 +22,11 @@ var __metadata = (this && this.__metadata) || function (k, v) {
     if (typeof Reflect === "object" && typeof Reflect.metadata === "function") return Reflect.metadata(k, v);
 };
 var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
     return new (P || (P = Promise))(function (resolve, reject) {
         function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
         function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
-        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
         step((generator = generator.apply(thisArg, _arguments || [])).next());
     });
 };

tests/baselines/reference/defaultExportInAwaitExpression01.js

@@ -29,10 +29,11 @@ import x from './a';
 });
 //// [b.js]
 var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
     return new (P || (P = Promise))(function (resolve, reject) {
         function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
         function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
-        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
         step((generator = generator.apply(thisArg, _arguments || [])).next());
     });
 };

tests/baselines/reference/defaultExportInAwaitExpression02.js

@@ -20,10 +20,11 @@ exports.default = x;
 //// [b.js]
 "use strict";
 var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
     return new (P || (P = Promise))(function (resolve, reject) {
         function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
         function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
-        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
         step((generator = generator.apply(thisArg, _arguments || [])).next());
     });
 };

tests/baselines/reference/docker/azure-sdk.log

@@ -1,20 +1,15 @@
 Exit Code: 1
 Standard output:
 
-Rush Multi-Project Build Tool 5.7.3 - https://rushjs.io
+Rush Multi-Project Build Tool 5.10.1 - https://rushjs.io
 Starting "rush rebuild"
 Executing a maximum of 1 simultaneous processes...
 [@azure/cosmos] started
-npm ERR! code ELIFECYCLE
-npm ERR! errno 2
-npm ERR! @azure/cosmos@X.X.X compile: `echo Using TypeScript && tsc --version && tsc -p tsconfig.prod.json --pretty`
-npm ERR! Exit status 2
-npm ERR! 
-npm ERR! Failed at the @azure/cosmos@X.X.X compile script.
-npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
-npm ERR! A complete log of this run can be found in:
-npm ERR!     /root/.npm/_logs/2019-07-11T13_39_53_628Z-debug.log
+XX of XX: [@azure/cosmos] completed successfully in ? seconds
+[@azure/event-processor-host] started
+XX of XX: [@azure/event-processor-host] completed successfully in ? seconds
 [@azure/service-bus] started
+Warning: You have changed the public API signature for this project. Updating review/service-bus.api.md
 [@azure/storage-blob] started
 XX of XX: [@azure/storage-blob] completed successfully in ? seconds
 [@azure/storage-file] started
@@ -23,6 +18,8 @@ XX of XX: [@azure/storage-file] completed successfully in ? seconds
 XX of XX: [@azure/storage-queue] completed successfully in ? seconds
 [@azure/template] started
 XX of XX: [@azure/template] completed successfully in ? seconds
+[testhub] started
+XX of XX: [testhub] completed successfully in ? seconds
 [@azure/abort-controller] started
 XX of XX: [@azure/abort-controller] completed successfully in ? seconds
 [@azure/core-asynciterator-polyfill] started
@@ -38,7 +35,7 @@ npm ERR!
 npm ERR! Failed at the @azure/core-http@X.X.X-preview.1 build:tsc script.
 npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
 npm ERR! A complete log of this run can be found in:
-npm ERR!     /root/.npm/_logs/2019-07-11T13_41_08_804Z-debug.log
+npm ERR!     /root/.npm/_logs/2019-07-19T13_40_31_496Z-debug.log
 ERROR: "build:tsc" exited with 2.
 npm ERR! code ELIFECYCLE
 npm ERR! errno 1
@@ -48,20 +45,17 @@ npm ERR!
 npm ERR! Failed at the @azure/core-http@X.X.X-preview.1 build:lib script.
 npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
 npm ERR! A complete log of this run can be found in:
-npm ERR!     /root/.npm/_logs/2019-07-11T13_41_08_852Z-debug.log
+npm ERR!     /root/.npm/_logs/2019-07-19T13_40_31_533Z-debug.log
 ERROR: "build:lib" exited with 1.
 [@azure/core-paging] started
 XX of XX: [@azure/core-paging] completed successfully in ? seconds
-[@azure/event-processor-host] started
-XX of XX: [@azure/event-processor-host] completed successfully in ? seconds
-[testhub] started
-XX of XX: [testhub] completed successfully in ? seconds
-SUCCESS (10)
+SUCCESS (11)
 ================================
 @azure/abort-controller (? seconds)
 @azure/core-asynciterator-polyfill (? seconds)
 @azure/core-auth (? seconds)
 @azure/core-paging (? seconds)
+@azure/cosmos (? seconds)
 @azure/event-processor-host (? seconds)
 @azure/storage-blob (? seconds)
 @azure/storage-file (? seconds)
@@ -69,6 +63,11 @@ SUCCESS (10)
 @azure/template (? seconds)
 testhub (? seconds)
 ================================
+SUCCESS WITH WARNINGS (1)
+================================
+@azure/service-bus (? seconds)
+Warning: You have changed the public API signature for this project. Updating review/service-bus.api.md
+================================
 BLOCKED (7)
 ================================
 @azure/core-amqp
@@ -79,7 +78,7 @@ BLOCKED (7)
 @azure/keyvault-keys
 @azure/keyvault-secrets
 ================================
-FAILURE (3)
+FAILURE (1)
 ================================
 @azure/core-http (? seconds)
 npm ERR! code ELIFECYCLE
@@ -90,7 +89,7 @@ npm ERR!
 npm ERR! Failed at the @azure/core-http@X.X.X-preview.1 build:tsc script.
 npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
 npm ERR! A complete log of this run can be found in:
-npm ERR!     /root/.npm/_logs/2019-07-11T13_41_08_804Z-debug.log
+npm ERR!     /root/.npm/_logs/2019-07-19T13_40_31_496Z-debug.log
 ERROR: "build:tsc" exited with 2.
 npm ERR! code ELIFECYCLE
 npm ERR! errno 1
@@ -100,24 +99,8 @@ npm ERR!
 npm ERR! Failed at the @azure/core-http@X.X.X-preview.1 build:lib script.
 npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
 npm ERR! A complete log of this run can be found in:
-npm ERR!     /root/.npm/_logs/2019-07-11T13_41_08_852Z-debug.log
+npm ERR!     /root/.npm/_logs/2019-07-19T13_40_31_533Z-debug.log
 ERROR: "build:lib" exited with 1.
-@azure/cosmos ( ? seconds)
-npm ERR! code ELIFECYCLE
-npm ERR! errno 2
-npm ERR! @azure/cosmos@X.X.X compile: `echo Using TypeScript && tsc --version && tsc -p tsconfig.prod.json --pretty`
-npm ERR! Exit status 2
-npm ERR!
-npm ERR! Failed at the @azure/cosmos@X.X.X compile script.
-npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
-npm ERR! A complete log of this run can be found in:
-npm ERR!     /root/.npm/_logs/2019-07-11T13_39_53_628Z-debug.log
-@azure/service-bus ( ? seconds)
->>> @azure/service-bus
-tsc -p . && rollup -c 2>&1 && npm run extract-api
-error TS2318: Cannot find global type 'AsyncGenerator'.
-src/receiver.ts(193,32): error TS2739: Type '{}' is missing the following properties from type 'AsyncIterableIterator<ServiceBusMessage>': [Symbol.asyncIterator], next
-src/receiver.ts(742,32): error TS2322: Type '{}' is not assignable to type 'AsyncIterableIterator<ServiceBusMessage>'.
 ================================
 Error: Project(s) failed to build
 rush rebuild - Errors! ( ? seconds)
@@ -126,8 +109,7 @@ rush rebuild - Errors! ( ? seconds)
 
 Standard error:
 Your version of Node.js (X.X.X) has not been tested with this release of Rush. The Rush team will not accept issue reports for it. Please consider upgrading Rush or downgrading Node.js.
-XX of XX: [@azure/cosmos] failed to build!
-XX of XX: [@azure/service-bus] failed to build!
+XX of XX: [@azure/service-bus] completed with warnings in ? seconds
 XX of XX: [@azure/core-http] failed to build!
 XX of XX: [@azure/core-arm] blocked by [@azure/core-http]!
 XX of XX: [@azure/identity] blocked by [@azure/core-http]!
@@ -137,5 +119,3 @@ XX of XX: [@azure/keyvault-certificates] blocked by [@azure/core-http]!
 XX of XX: [@azure/keyvault-keys] blocked by [@azure/core-http]!
 XX of XX: [@azure/keyvault-secrets] blocked by [@azure/core-http]!
 [@azure/core-http] Returned error code: 1
-[@azure/cosmos] Returned error code: 2
-[@azure/service-bus] Returned error code: 2

tests/baselines/reference/docker/office-ui-fabric.log

@@ -10,12 +10,24 @@ XX of XX: [@uifabric/prettier-rules] completed successfully in ? seconds
 XX of XX: [@uifabric/tslint-rules] completed successfully in ? seconds
 [@uifabric/codepen-loader] started
 ts-jest[versions] (WARN) Version X.X.X-insiders.xxxxxxxx of typescript installed has not been tested with ts-jest. If you're experiencing issues, consider using a supported version (>=2.7.0 <4.0.0). Please do not report issues in ts-jest if you are using unsupported versions.
+ PASS  src/__tests__/codepenTransform.test.ts
+  codepen transform
+    ✓ handles examples with function components (256ms)
+    ✓ handles examples with class components (38ms)
+    ✓ handles examples importing exampleData (125ms)
+    ✓ handles examples importing TestImages (33ms)
+    ✓ handles examples importing PeopleExampleData (270ms)
+Test Suites: 1 passed, 1 total
+Tests:       5 passed, 5 total
+Snapshots:   4 passed, 4 total
+Time:        ?s
+Ran all test suites.
 [@uifabric/build] started
 XX of XX: [@uifabric/build] completed successfully in ? seconds
 [@uifabric/migration] started
 XX of XX: [@uifabric/migration] completed successfully in ? seconds
 [@uifabric/set-version] started
-ts-jest[versions] (WARN) Version X.X.X-insiders.xxxxxxxx of typescript installed has not been tested with ts-jest. If you're experiencing issues, consider using a supported version (>=2.7.0 <4.0.0). Please do not report issues in ts-jest if you are using unsupported versions.
+XX of XX: [@uifabric/set-version] completed successfully in ? seconds
 [@uifabric/merge-styles] started
 ts-jest[versions] (WARN) Version X.X.X-insiders.xxxxxxxx of typescript installed has not been tested with ts-jest. If you're experiencing issues, consider using a supported version (>=2.7.0 <4.0.0). Please do not report issues in ts-jest if you are using unsupported versions.
 [@uifabric/jest-serializer-merge-styles] started
@@ -204,7 +216,7 @@ ts-jest[versions] (WARN) Version X.X.X-insiders.xxxxxxxx of typescript installed
 [XX:XX:XX XM] x Error detected while running 'jest'
 [XX:XX:XX XM] x ------------------------------------
 [XX:XX:XX XM] x Error: Command failed: /usr/local/bin/node /office-ui-fabric-react/common/temp/node_modules/jest/bin/jest.js --config /office-ui-fabric-react/packages/foundation/jest.config.js --passWithNoTests --colors
-    at ChildProcess.<anonymous> (/office-ui-fabric-react/common/temp/node_modules/.registry.npmjs.org/just-scripts-utils/0.8.1/node_modules/just-scripts-utils/lib/exec.js:70:31)
+    at ChildProcess.<anonymous> (/office-ui-fabric-react/common/temp/node_modules/.registry.npmjs.org/just-scripts-utils/0.8.2/node_modules/just-scripts-utils/lib/exec.js:70:31)
     at ChildProcess.emit (events.js:203:13)
     at ChildProcess.EventEmitter.emit (domain.js:494:23)
     at Process.ChildProcess._handle.onexit (internal/child_process.js:272:12)
@@ -216,27 +228,38 @@ ts-jest[versions] (WARN) Version X.X.X-insiders.xxxxxxxx of typescript installed
 XX of XX: [@uifabric/icons] completed successfully in ? seconds
 [@uifabric/webpack-utils] started
 XX of XX: [@uifabric/webpack-utils] completed successfully in ? seconds
-SUCCESS (8)
+SUCCESS (9)
 ================================
 @uifabric/build (? seconds)
 @uifabric/file-type-icons (? seconds)
 @uifabric/icons (? seconds)
 @uifabric/migration (? seconds)
 @uifabric/prettier-rules (? seconds)
+@uifabric/set-version (? seconds)
 @uifabric/test-utilities (? seconds)
 @uifabric/tslint-rules (? seconds)
 @uifabric/webpack-utils (? seconds)
 ================================
-SUCCESS WITH WARNINGS (6)
+SUCCESS WITH WARNINGS (5)
 ================================
 @uifabric/codepen-loader (? seconds)
 ts-jest[versions] (WARN) Version X.X.X-insiders.xxxxxxxx of typescript installed has not been tested with ts-jest. If you're experiencing issues, consider using a supported version (>=2.7.0 <4.0.0). Please do not report issues in ts-jest if you are using unsupported versions.
+ PASS  src/__tests__/codepenTransform.test.ts
+  codepen transform
+    ✓ handles examples with function components (256ms)
+    ✓ handles examples with class components (38ms)
+    ✓ handles examples importing exampleData (125ms)
+    ✓ handles examples importing TestImages (33ms)
+    ✓ handles examples importing PeopleExampleData (270ms)
+Test Suites: 1 passed, 1 total
+Tests:       5 passed, 5 total
+Snapshots:   4 passed, 4 total
+Time:        ?s
+Ran all test suites.
 @uifabric/jest-serializer-merge-styles (? seconds)
 ts-jest[versions] (WARN) Version X.X.X-insiders.xxxxxxxx of typescript installed has not been tested with ts-jest. If you're experiencing issues, consider using a supported version (>=2.7.0 <4.0.0). Please do not report issues in ts-jest if you are using unsupported versions.
 @uifabric/merge-styles (? seconds)
 ts-jest[versions] (WARN) Version X.X.X-insiders.xxxxxxxx of typescript installed has not been tested with ts-jest. If you're experiencing issues, consider using a supported version (>=2.7.0 <4.0.0). Please do not report issues in ts-jest if you are using unsupported versions.
-@uifabric/set-version (? seconds)
-ts-jest[versions] (WARN) Version X.X.X-insiders.xxxxxxxx of typescript installed has not been tested with ts-jest. If you're experiencing issues, consider using a supported version (>=2.7.0 <4.0.0). Please do not report issues in ts-jest if you are using unsupported versions.
 @uifabric/styling (? seconds)
 ts-jest[versions] (WARN) Version X.X.X-insiders.xxxxxxxx of typescript installed has not been tested with ts-jest. If you're experiencing issues, consider using a supported version (>=2.7.0 <4.0.0). Please do not report issues in ts-jest if you are using unsupported versions.
 @uifabric/utilities (? seconds)
@@ -296,7 +319,7 @@ ts-jest[versions] (WARN) Version X.X.X-insiders.xxxxxxxx of typescript installed
 [XX:XX:XX XM] x Error detected while running 'jest'
 [XX:XX:XX XM] x ------------------------------------
 [XX:XX:XX XM] x Error: Command failed: /usr/local/bin/node /office-ui-fabric-react/common/temp/node_modules/jest/bin/jest.js --config /office-ui-fabric-react/packages/foundation/jest.config.js --passWithNoTests --colors
-    at ChildProcess.<anonymous> (/office-ui-fabric-react/common/temp/node_modules/.registry.npmjs.org/just-scripts-utils/0.8.1/node_modules/just-scripts-utils/lib/exec.js:70:31)
+    at ChildProcess.<anonymous> (/office-ui-fabric-react/common/temp/node_modules/.registry.npmjs.org/just-scripts-utils/0.8.2/node_modules/just-scripts-utils/lib/exec.js:70:31)
     at ChildProcess.emit (events.js:203:13)
     at ChildProcess.EventEmitter.emit (domain.js:494:23)
     at Process.ChildProcess._handle.onexit (internal/child_process.js:272:12)
@@ -313,7 +336,6 @@ rush rebuild - Errors! ( ? seconds)
 Standard error:
 Your version of Node.js (X.X.X) has not been tested with this release of Rush. The Rush team will not accept issue reports for it. Please consider upgrading Rush or downgrading Node.js.
 XX of XX: [@uifabric/codepen-loader] completed with warnings in ? seconds
-XX of XX: [@uifabric/set-version] completed with warnings in ? seconds
 XX of XX: [@uifabric/merge-styles] completed with warnings in ? seconds
 XX of XX: [@uifabric/jest-serializer-merge-styles] completed with warnings in ? seconds
 XX of XX: [@uifabric/utilities] completed with warnings in ? seconds

tests/baselines/reference/emitter.forAwait.es2015.js

@@ -43,10 +43,11 @@ async function* f6() {
 
 //// [file1.js]
 var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
     return new (P || (P = Promise))(function (resolve, reject) {
         function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
         function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
-        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
         step((generator = generator.apply(thisArg, _arguments || [])).next());
     });
 };
@@ -77,10 +78,11 @@ function f1() {
 }
 //// [file2.js]
 var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
     return new (P || (P = Promise))(function (resolve, reject) {
         function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
         function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
-        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
         step((generator = generator.apply(thisArg, _arguments || [])).next());
     });
 };
@@ -187,10 +189,11 @@ function f4() {
 }
 //// [file5.js]
 var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
     return new (P || (P = Promise))(function (resolve, reject) {
         function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
         function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
-        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
         step((generator = generator.apply(thisArg, _arguments || [])).next());
     });
 };

tests/baselines/reference/emitter.forAwait.es5.js

@@ -43,10 +43,11 @@ async function* f6() {
 
 //// [file1.js]
 var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
     return new (P || (P = Promise))(function (resolve, reject) {
         function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
         function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
-        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
         step((generator = generator.apply(thisArg, _arguments || [])).next());
     });
 };
@@ -124,10 +125,11 @@ function f1() {
 }
 //// [file2.js]
 var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
     return new (P || (P = Promise))(function (resolve, reject) {
         function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
         function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
-        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
         step((generator = generator.apply(thisArg, _arguments || [])).next());
     });
 };
@@ -375,10 +377,11 @@ function f4() {
 }
 //// [file5.js]
 var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
     return new (P || (P = Promise))(function (resolve, reject) {
         function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
         function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
-        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
         step((generator = generator.apply(thisArg, _arguments || [])).next());
     });
 };

tests/baselines/reference/es5-asyncFunction.js

@@ -10,10 +10,11 @@ async function singleAwait() {
 
 //// [es5-asyncFunction.js]
 var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
     return new (P || (P = Promise))(function (resolve, reject) {
         function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
         function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
-        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
         step((generator = generator.apply(thisArg, _arguments || [])).next());
     });
 };

tests/baselines/reference/es5-importHelpersAsyncFunctions.js

@@ -31,10 +31,11 @@ function foo() {
 exports.foo = foo;
 //// [script.js]
 var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
     return new (P || (P = Promise))(function (resolve, reject) {
         function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
         function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
-        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
         step((generator = generator.apply(thisArg, _arguments || [])).next());
     });
 };

tests/baselines/reference/excessPropertyCheckWithSpread.js

@@ -30,4 +30,4 @@ var __assign = (this && this.__assign) || function () {
     return __assign.apply(this, arguments);
 };
 f(__assign({ a: 1 }, i));
-f(__assign({ a: 1 }, l, r));
+f(__assign(__assign({ a: 1 }, l), r));

tests/baselines/reference/exportDefaultAsyncFunction.js

@@ -5,10 +5,11 @@ foo();
 
 //// [exportDefaultAsyncFunction.js]
 var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
     return new (P || (P = Promise))(function (resolve, reject) {
         function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
         function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
-        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
         step((generator = generator.apply(thisArg, _arguments || [])).next());
     });
 };

tests/baselines/reference/exportDefaultAsyncFunction2.js

@@ -35,10 +35,11 @@ import { async, await } from 'asyncawait';
 export default async(() => await(Promise.resolve(1)));
 //// [b.js]
 var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
     return new (P || (P = Promise))(function (resolve, reject) {
         function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
         function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
-        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
         step((generator = generator.apply(thisArg, _arguments || [])).next());
     });
 };

tests/baselines/reference/exportDefaultFunctionInNamespace.js

@@ -10,10 +10,11 @@ namespace ns_async_function {
 
 //// [exportDefaultFunctionInNamespace.js]
 var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
     return new (P || (P = Promise))(function (resolve, reject) {
         function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
         function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
-        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
         step((generator = generator.apply(thisArg, _arguments || [])).next());
     });
 };

tests/baselines/reference/expressionsForbiddenInParameterInitializers.js

@@ -9,10 +9,11 @@ export function* foo2({ foo = yield "a" }) {
 //// [bar.js]
 "use strict";
 var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
     return new (P || (P = Promise))(function (resolve, reject) {
         function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
         function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
-        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
         step((generator = generator.apply(thisArg, _arguments || [])).next());
     });
 };

tests/baselines/reference/generatorReturnTypeFallback.1.symbols

@@ -0,0 +1,7 @@
+=== tests/cases/conformance/generators/generatorReturnTypeFallback.1.ts ===
+// Allow generators to fallback to IterableIterator if they do not need a type for the sent value while in strictNullChecks mode.
+function* f() {
+>f : Symbol(f, Decl(generatorReturnTypeFallback.1.ts, 0, 0))
+
+    yield 1;
+}

tests/baselines/reference/generatorReturnTypeFallback.1.types

@@ -0,0 +1,9 @@
+=== tests/cases/conformance/generators/generatorReturnTypeFallback.1.ts ===
+// Allow generators to fallback to IterableIterator if they do not need a type for the sent value while in strictNullChecks mode.
+function* f() {
+>f : () => IterableIterator<number>
+
+    yield 1;
+>yield 1 : any
+>1 : 1
+}

tests/baselines/reference/generatorReturnTypeFallback.2.errors.txt

@@ -0,0 +1,10 @@
+error TS2318: Cannot find global type 'IterableIterator'.
+
+
+!!! error TS2318: Cannot find global type 'IterableIterator'.
+==== tests/cases/conformance/generators/generatorReturnTypeFallback.2.ts (0 errors) ====
+    // Allow generators to fallback to IterableIterator if they do not need a type for the sent value while in strictNullChecks mode.
+    // Report an error if IterableIterator cannot be found.
+    function* f() {
+        yield 1;
+    }

tests/baselines/reference/generatorReturnTypeFallback.2.symbols

@@ -0,0 +1,8 @@
+=== tests/cases/conformance/generators/generatorReturnTypeFallback.2.ts ===
+// Allow generators to fallback to IterableIterator if they do not need a type for the sent value while in strictNullChecks mode.
+// Report an error if IterableIterator cannot be found.
+function* f() {
+>f : Symbol(f, Decl(generatorReturnTypeFallback.2.ts, 0, 0))
+
+    yield 1;
+}

tests/baselines/reference/generatorReturnTypeFallback.2.types

@@ -0,0 +1,10 @@
+=== tests/cases/conformance/generators/generatorReturnTypeFallback.2.ts ===
+// Allow generators to fallback to IterableIterator if they do not need a type for the sent value while in strictNullChecks mode.
+// Report an error if IterableIterator cannot be found.
+function* f() {
+>f : () => {}
+
+    yield 1;
+>yield 1 : any
+>1 : 1
+}

tests/baselines/reference/generatorReturnTypeFallback.3.errors.txt

@@ -0,0 +1,10 @@
+error TS2318: Cannot find global type 'Generator'.
+
+
+!!! error TS2318: Cannot find global type 'Generator'.
+==== tests/cases/conformance/generators/generatorReturnTypeFallback.3.ts (0 errors) ====
+    // Do not allow generators to fallback to IterableIterator while in strictNullChecks mode if they need a type for the sent value.
+    // NOTE: In non-strictNullChecks mode, `undefined` (the default sent value) is assignable to everything.
+    function* f() {
+        const x: string = yield 1;
+    }

tests/baselines/reference/generatorReturnTypeFallback.3.symbols

@@ -0,0 +1,9 @@
+=== tests/cases/conformance/generators/generatorReturnTypeFallback.3.ts ===
+// Do not allow generators to fallback to IterableIterator while in strictNullChecks mode if they need a type for the sent value.
+// NOTE: In non-strictNullChecks mode, `undefined` (the default sent value) is assignable to everything.
+function* f() {
+>f : Symbol(f, Decl(generatorReturnTypeFallback.3.ts, 0, 0))
+
+    const x: string = yield 1;
+>x : Symbol(x, Decl(generatorReturnTypeFallback.3.ts, 3, 9))
+}

tests/baselines/reference/generatorReturnTypeFallback.3.types

@@ -0,0 +1,11 @@
+=== tests/cases/conformance/generators/generatorReturnTypeFallback.3.ts ===
+// Do not allow generators to fallback to IterableIterator while in strictNullChecks mode if they need a type for the sent value.
+// NOTE: In non-strictNullChecks mode, `undefined` (the default sent value) is assignable to everything.
+function* f() {
+>f : () => {}
+
+    const x: string = yield 1;
+>x : string
+>yield 1 : any
+>1 : 1
+}

tests/baselines/reference/generatorReturnTypeFallback.4.symbols

@@ -0,0 +1,9 @@
+=== tests/cases/conformance/generators/generatorReturnTypeFallback.4.ts ===
+// Allow generators to fallback to IterableIterator if they are not in strictNullChecks mode
+// NOTE: In non-strictNullChecks mode, `undefined` (the default sent value) is assignable to everything.
+function* f() {
+>f : Symbol(f, Decl(generatorReturnTypeFallback.4.ts, 0, 0))
+
+    const x: string = yield 1;
+>x : Symbol(x, Decl(generatorReturnTypeFallback.4.ts, 3, 9))
+}

tests/baselines/reference/generatorReturnTypeFallback.4.types

@@ -0,0 +1,11 @@
+=== tests/cases/conformance/generators/generatorReturnTypeFallback.4.ts ===
+// Allow generators to fallback to IterableIterator if they are not in strictNullChecks mode
+// NOTE: In non-strictNullChecks mode, `undefined` (the default sent value) is assignable to everything.
+function* f() {
+>f : () => IterableIterator<number>
+
+    const x: string = yield 1;
+>x : string
+>yield 1 : any
+>1 : 1
+}

tests/baselines/reference/generatorReturnTypeFallback.5.symbols

@@ -0,0 +1,8 @@
+=== tests/cases/conformance/generators/generatorReturnTypeFallback.5.ts ===
+// Allow generators to fallback to IterableIterator if they do not need a type for the sent value while in strictNullChecks mode.
+function* f(): IterableIterator<number> {
+>f : Symbol(f, Decl(generatorReturnTypeFallback.5.ts, 0, 0))
+>IterableIterator : Symbol(IterableIterator, Decl(lib.es2015.iterable.d.ts, --, --))
+
+    yield 1;
+}