From b4b711ff5c7e5f07db43c139309b4e34fdcda853 Mon Sep 17 00:00:00 2001
From: Anders Hejlsberg <andersh@microsoft.com>
Date: Mon, 23 Oct 2017 12:35:11 -0700
Subject: [PATCH 1/7] Infer from base constraint signatures instead of erased
 signatures

---
 src/compiler/checker.ts | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index da3dac4d605..6938ed8d77f 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -6726,6 +6726,16 @@ namespace ts {
                 isInJavaScriptFile(signature.declaration));
         }
 
+        function getBaseSignature(signature: Signature) {
+            const typeParameters = signature.typeParameters;
+            if (typeParameters) {
+                const typeEraser = createTypeEraser(typeParameters);
+                const baseConstraints = map(typeParameters, tp => instantiateType(getBaseConstraintOfType(tp), typeEraser) || emptyObjectType);
+                return instantiateSignature(signature, createTypeMapper(typeParameters, baseConstraints), /*eraseTypeParameters*/ true);
+            }
+            return signature;
+        }
+
         function getOrCreateTypeFromSignature(signature: Signature): ObjectType {
             // There are two ways to declare a construct signature, one is by declaring a class constructor
             // using the constructor keyword, and the other is declaring a bare construct signature in an
@@ -10955,7 +10965,7 @@ namespace ts {
                 const targetLen = targetSignatures.length;
                 const len = sourceLen < targetLen ? sourceLen : targetLen;
                 for (let i = 0; i < len; i++) {
-                    inferFromSignature(getErasedSignature(sourceSignatures[sourceLen - len + i]), getErasedSignature(targetSignatures[targetLen - len + i]));
+                    inferFromSignature(getBaseSignature(sourceSignatures[sourceLen - len + i]), getBaseSignature(targetSignatures[targetLen - len + i]));
                 }
             }
 

From a87baa2664fa51fd4e8e29c47599aece5ccd45ff Mon Sep 17 00:00:00 2001
From: Anders Hejlsberg <andersh@microsoft.com>
Date: Mon, 23 Oct 2017 12:36:29 -0700
Subject: [PATCH 2/7] Accept new baselines

---
 ...lWithConstructorTypedArguments5.errors.txt |  8 +++----
 ...nericCallWithFunctionTypedArguments2.types | 24 +++++++++----------
 ...hOverloadedConstructorTypedArguments.types | 20 ++++++++--------
 ...oadedConstructorTypedArguments2.errors.txt |  4 ++--
 ...OverloadedConstructorTypedArguments2.types | 12 +++++-----
 ...WithOverloadedFunctionTypedArguments.types | 20 ++++++++--------
 ...erloadedFunctionTypedArguments2.errors.txt |  4 ++--
 ...ithOverloadedFunctionTypedArguments2.types | 12 +++++-----
 .../reference/promisePermutations.types       | 16 ++++++-------
 .../reference/promisePermutations2.types      | 16 ++++++-------
 .../reference/promisePermutations3.errors.txt |  8 +++----
 .../reference/promisePermutations3.types      | 12 +++++-----
 12 files changed, 78 insertions(+), 78 deletions(-)

diff --git a/tests/baselines/reference/genericCallWithConstructorTypedArguments5.errors.txt b/tests/baselines/reference/genericCallWithConstructorTypedArguments5.errors.txt
index a014ef85b6c..4aa29b1e050 100644
--- a/tests/baselines/reference/genericCallWithConstructorTypedArguments5.errors.txt
+++ b/tests/baselines/reference/genericCallWithConstructorTypedArguments5.errors.txt
@@ -1,6 +1,6 @@
-tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithConstructorTypedArguments5.ts(11,14): error TS2345: Argument of type '{ cb: new <T>(x: T, y: T) => string; }' is not assignable to parameter of type '{ cb: new (t: any) => string; }'.
+tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithConstructorTypedArguments5.ts(11,14): error TS2345: Argument of type '{ cb: new <T>(x: T, y: T) => string; }' is not assignable to parameter of type '{ cb: new (t: {}) => string; }'.
   Types of property 'cb' are incompatible.
-    Type 'new <T>(x: T, y: T) => string' is not assignable to type 'new (t: any) => string'.
+    Type 'new <T>(x: T, y: T) => string' is not assignable to type 'new (t: {}) => string'.
 tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithConstructorTypedArguments5.ts(13,14): error TS2345: Argument of type '{ cb: new (x: string, y: number) => string; }' is not assignable to parameter of type '{ cb: new (t: string) => string; }'.
   Types of property 'cb' are incompatible.
     Type 'new (x: string, y: number) => string' is not assignable to type 'new (t: string) => string'.
@@ -19,9 +19,9 @@ tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithCon
     var arg2: { cb: new <T>(x: T, y: T) => string };
     var r2 = foo(arg2); // error
                  ~~~~
-!!! error TS2345: Argument of type '{ cb: new <T>(x: T, y: T) => string; }' is not assignable to parameter of type '{ cb: new (t: any) => string; }'.
+!!! error TS2345: Argument of type '{ cb: new <T>(x: T, y: T) => string; }' is not assignable to parameter of type '{ cb: new (t: {}) => string; }'.
 !!! error TS2345:   Types of property 'cb' are incompatible.
-!!! error TS2345:     Type 'new <T>(x: T, y: T) => string' is not assignable to type 'new (t: any) => string'.
+!!! error TS2345:     Type 'new <T>(x: T, y: T) => string' is not assignable to type 'new (t: {}) => string'.
     var arg3: { cb: new (x: string, y: number) => string };
     var r3 = foo(arg3); // error
                  ~~~~
diff --git a/tests/baselines/reference/genericCallWithFunctionTypedArguments2.types b/tests/baselines/reference/genericCallWithFunctionTypedArguments2.types
index 16bc5ae774a..967850180d6 100644
--- a/tests/baselines/reference/genericCallWithFunctionTypedArguments2.types
+++ b/tests/baselines/reference/genericCallWithFunctionTypedArguments2.types
@@ -53,8 +53,8 @@ var a: {
 }
 
 var r = foo(i); // any
->r : any
->foo(i) : any
+>r : {}
+>foo(i) : {}
 >foo : <T>(x: new (a: T) => T) => T
 >i : I
 
@@ -71,8 +71,8 @@ var r3 = foo(i2); // string
 >i2 : I2<string>
 
 var r3b = foo(a); // any
->r3b : any
->foo(a) : any
+>r3b : {}
+>foo(a) : {}
 >foo : <T>(x: new (a: T) => T) => T
 >a : new <T>(x: T) => T
 
@@ -101,15 +101,15 @@ var r4 = foo2(1, i2); // error
 >i2 : I2<string>
 
 var r4b = foo2(1, a); // any
->r4b : any
->foo2(1, a) : any
+>r4b : {}
+>foo2(1, a) : {}
 >foo2 : <T, U>(x: T, cb: new (a: T) => U) => U
 >1 : 1
 >a : new <T>(x: T) => T
 
 var r5 = foo2(1, i); // any
->r5 : any
->foo2(1, i) : any
+>r5 : {}
+>foo2(1, i) : {}
 >foo2 : <T, U>(x: T, cb: new (a: T) => U) => U
 >1 : 1
 >i : I
@@ -141,16 +141,16 @@ function foo3<T, U>(x: T, cb: new(a: T) => U, y: U) {
 }
 
 var r7 = foo3(null, i, ''); // any
->r7 : any
->foo3(null, i, '') : any
+>r7 : {}
+>foo3(null, i, '') : {}
 >foo3 : <T, U>(x: T, cb: new (a: T) => U, y: U) => U
 >null : null
 >i : I
 >'' : ""
 
 var r7b = foo3(null, a, ''); // any
->r7b : any
->foo3(null, a, '') : any
+>r7b : {}
+>foo3(null, a, '') : {}
 >foo3 : <T, U>(x: T, cb: new (a: T) => U, y: U) => U
 >null : null
 >a : new <T>(x: T) => T
diff --git a/tests/baselines/reference/genericCallWithOverloadedConstructorTypedArguments.types b/tests/baselines/reference/genericCallWithOverloadedConstructorTypedArguments.types
index 15e746f615a..682910656ff 100644
--- a/tests/baselines/reference/genericCallWithOverloadedConstructorTypedArguments.types
+++ b/tests/baselines/reference/genericCallWithOverloadedConstructorTypedArguments.types
@@ -87,8 +87,8 @@ module GenericParameter {
 >T : T
 
     var r7 = foo5(b); // new any => string; new(x:number) => any
->r7 : { new (x: any): string; new (x: number): any; }
->foo5(b) : { new (x: any): string; new (x: number): any; }
+>r7 : { new (x: {}): string; new (x: number): {}; }
+>foo5(b) : { new (x: {}): string; new (x: number): {}; }
 >foo5 : <T>(cb: { new (x: T): string; new (x: number): T; }) => { new (x: T): string; new (x: number): T; }
 >b : { new <T>(x: T): string; new <T>(x: number): T; }
 
@@ -114,8 +114,8 @@ module GenericParameter {
 >a : { new (x: boolean): string; new (x: number): boolean; }
 
     var r9 = foo6(b); // new any => string; new(x:any, y?:any) => string
->r9 : { new (x: any): string; new (x: any, y?: any): string; }
->foo6(b) : { new (x: any): string; new (x: any, y?: any): string; }
+>r9 : { new (x: {}): string; new (x: {}, y?: {}): string; }
+>foo6(b) : { new (x: {}): string; new (x: {}, y?: {}): string; }
 >foo6 : <T>(cb: { new (x: T): string; new (x: T, y?: T): string; }) => { new (x: T): string; new (x: T, y?: T): string; }
 >b : { new <T>(x: T): string; new <T>(x: number): T; }
 
@@ -137,8 +137,8 @@ module GenericParameter {
     }
 
     var r13 = foo7(1, b); // new any => string; new(x:any, y?:any) => string
->r13 : { new (x: any): string; new (x: any, y?: any): string; }
->foo7(1, b) : { new (x: any): string; new (x: any, y?: any): string; }
+>r13 : { new (x: {}): string; new (x: {}, y?: {}): string; }
+>foo7(1, b) : { new (x: {}): string; new (x: {}, y?: {}): string; }
 >foo7 : <T>(x: T, cb: { new (x: T): string; new (x: T, y?: T): string; }) => { new (x: T): string; new (x: T, y?: T): string; }
 >1 : 1
 >b : { new <T>(x: T): string; new <T>(x: number): T; }
@@ -162,15 +162,15 @@ module GenericParameter {
 >T : T
 
     var r14 = foo7(1, c); // new any => string; new(x:any, y?:any) => string
->r14 : { new (x: any): string; new (x: any, y?: any): string; }
->foo7(1, c) : { new (x: any): string; new (x: any, y?: any): string; }
+>r14 : { new (x: {}): string; new (x: {}, y?: {}): string; }
+>foo7(1, c) : { new (x: {}): string; new (x: {}, y?: {}): string; }
 >foo7 : <T>(x: T, cb: { new (x: T): string; new (x: T, y?: T): string; }) => { new (x: T): string; new (x: T, y?: T): string; }
 >1 : 1
 >c : { <T>(x: number): T; new <T>(x: T): string; }
 
     var r15 = foo7(1, c2); // new any => string; new(x:any, y?:any) => string
->r15 : { new (x: any): string; new (x: any, y?: any): string; }
->foo7(1, c2) : { new (x: any): string; new (x: any, y?: any): string; }
+>r15 : { new (x: {}): string; new (x: {}, y?: {}): string; }
+>foo7(1, c2) : { new (x: {}): string; new (x: {}, y?: {}): string; }
 >foo7 : <T>(x: T, cb: { new (x: T): string; new (x: T, y?: T): string; }) => { new (x: T): string; new (x: T, y?: T): string; }
 >1 : 1
 >c2 : { new <T>(x: T): string; new <T>(x: number): T; }
diff --git a/tests/baselines/reference/genericCallWithOverloadedConstructorTypedArguments2.errors.txt b/tests/baselines/reference/genericCallWithOverloadedConstructorTypedArguments2.errors.txt
index 80bcf12494a..cb40b4acb7a 100644
--- a/tests/baselines/reference/genericCallWithOverloadedConstructorTypedArguments2.errors.txt
+++ b/tests/baselines/reference/genericCallWithOverloadedConstructorTypedArguments2.errors.txt
@@ -1,4 +1,4 @@
-tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithOverloadedConstructorTypedArguments2.ts(31,20): error TS2345: Argument of type 'new <T>(x: T, y: T) => string' is not assignable to parameter of type '{ new (x: any): string; new (x: any, y?: any): string; }'.
+tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithOverloadedConstructorTypedArguments2.ts(31,20): error TS2345: Argument of type 'new <T>(x: T, y: T) => string' is not assignable to parameter of type '{ new (x: {}): string; new (x: {}, y?: {}): string; }'.
 
 
 ==== tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithOverloadedConstructorTypedArguments2.ts (1 errors) ====
@@ -34,7 +34,7 @@ tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithOve
         var b: { new <T>(x: T, y: T): string };
         var r10 = foo6(b); // error
                        ~
-!!! error TS2345: Argument of type 'new <T>(x: T, y: T) => string' is not assignable to parameter of type '{ new (x: any): string; new (x: any, y?: any): string; }'.
+!!! error TS2345: Argument of type 'new <T>(x: T, y: T) => string' is not assignable to parameter of type '{ new (x: {}): string; new (x: {}, y?: {}): string; }'.
     
         function foo7<T>(x:T, cb: { new(x: T): string; new(x: T, y?: T): string }) {
             return cb;
diff --git a/tests/baselines/reference/genericCallWithOverloadedConstructorTypedArguments2.types b/tests/baselines/reference/genericCallWithOverloadedConstructorTypedArguments2.types
index e9b65c6f1da..557c63914fe 100644
--- a/tests/baselines/reference/genericCallWithOverloadedConstructorTypedArguments2.types
+++ b/tests/baselines/reference/genericCallWithOverloadedConstructorTypedArguments2.types
@@ -63,8 +63,8 @@ module GenericParameter {
 >T : T
 
     var r6 = foo5(a); // ok
->r6 : { new (x: any): string; new (x: number): any; }
->foo5(a) : { new (x: any): string; new (x: number): any; }
+>r6 : { new (x: {}): string; new (x: number): {}; }
+>foo5(a) : { new (x: {}): string; new (x: number): {}; }
 >foo5 : <T>(cb: { new (x: T): string; new (x: number): T; }) => { new (x: T): string; new (x: number): T; }
 >a : new <T>(x: T) => T
 
@@ -115,8 +115,8 @@ module GenericParameter {
     }
 
     var r13 = foo7(1, a); // ok
->r13 : { new (x: any): string; new (x: any, y?: any): string; }
->foo7(1, a) : { new (x: any): string; new (x: any, y?: any): string; }
+>r13 : { new (x: {}): string; new (x: {}, y?: {}): string; }
+>foo7(1, a) : { new (x: {}): string; new (x: {}, y?: {}): string; }
 >foo7 : <T>(x: T, cb: { new (x: T): string; new (x: T, y?: T): string; }) => { new (x: T): string; new (x: T, y?: T): string; }
 >1 : 1
 >a : new <T>(x: T) => T
@@ -131,8 +131,8 @@ module GenericParameter {
 >T : T
 
     var r14 = foo7(1, c); // ok
->r14 : { new (x: any): string; new (x: any, y?: any): string; }
->foo7(1, c) : { new (x: any): string; new (x: any, y?: any): string; }
+>r14 : { new (x: {}): string; new (x: {}, y?: {}): string; }
+>foo7(1, c) : { new (x: {}): string; new (x: {}, y?: {}): string; }
 >foo7 : <T>(x: T, cb: { new (x: T): string; new (x: T, y?: T): string; }) => { new (x: T): string; new (x: T, y?: T): string; }
 >1 : 1
 >c : { new <T>(x: T): number; new <T>(x: number): T; }
diff --git a/tests/baselines/reference/genericCallWithOverloadedFunctionTypedArguments.types b/tests/baselines/reference/genericCallWithOverloadedFunctionTypedArguments.types
index ab07e9c880a..55bec0c2a9f 100644
--- a/tests/baselines/reference/genericCallWithOverloadedFunctionTypedArguments.types
+++ b/tests/baselines/reference/genericCallWithOverloadedFunctionTypedArguments.types
@@ -83,8 +83,8 @@ module GenericParameter {
 >T : T
 
     var r7 = foo5(a); // any => string (+1 overload)
->r7 : { (x: any): string; (x: number): any; }
->foo5(a) : { (x: any): string; (x: number): any; }
+>r7 : { (x: {}): string; (x: number): {}; }
+>foo5(a) : { (x: {}): string; (x: number): {}; }
 >foo5 : <T>(cb: { (x: T): string; (x: number): T; }) => { (x: T): string; (x: number): T; }
 >a : { <T>(x: T): string; <T>(x: number): T; }
 
@@ -112,8 +112,8 @@ module GenericParameter {
 >x : any
 
     var r9 = foo6(<T>(x: T) => ''); // any => string (+1 overload)
->r9 : { (x: any): string; (x: any, y?: any): string; }
->foo6(<T>(x: T) => '') : { (x: any): string; (x: any, y?: any): string; }
+>r9 : { (x: {}): string; (x: {}, y?: {}): string; }
+>foo6(<T>(x: T) => '') : { (x: {}): string; (x: {}, y?: {}): string; }
 >foo6 : <T>(cb: { (x: T): string; (x: T, y?: T): string; }) => { (x: T): string; (x: T, y?: T): string; }
 ><T>(x: T) => '' : <T>(x: T) => string
 >T : T
@@ -122,8 +122,8 @@ module GenericParameter {
 >'' : ""
 
     var r11 = foo6(<T>(x: T, y?: T) => ''); // any => string (+1 overload)
->r11 : { (x: any): string; (x: any, y?: any): string; }
->foo6(<T>(x: T, y?: T) => '') : { (x: any): string; (x: any, y?: any): string; }
+>r11 : { (x: {}): string; (x: {}, y?: {}): string; }
+>foo6(<T>(x: T, y?: T) => '') : { (x: {}): string; (x: {}, y?: {}): string; }
 >foo6 : <T>(cb: { (x: T): string; (x: T, y?: T): string; }) => { (x: T): string; (x: T, y?: T): string; }
 ><T>(x: T, y?: T) => '' : <T>(x: T, y?: T) => string
 >T : T
@@ -160,8 +160,8 @@ module GenericParameter {
 >x : any
 
     var r13 = foo7(1, <T>(x: T) => ''); // any => string (+1 overload) [inferences are made for T, but lambda not contextually typed]
->r13 : { (x: any): string; (x: any, y?: any): string; }
->foo7(1, <T>(x: T) => '') : { (x: any): string; (x: any, y?: any): string; }
+>r13 : { (x: {}): string; (x: {}, y?: {}): string; }
+>foo7(1, <T>(x: T) => '') : { (x: {}): string; (x: {}, y?: {}): string; }
 >foo7 : <T>(x: T, cb: { (x: T): string; (x: T, y?: T): string; }) => { (x: T): string; (x: T, y?: T): string; }
 >1 : 1
 ><T>(x: T) => '' : <T>(x: T) => string
@@ -180,8 +180,8 @@ module GenericParameter {
 >T : T
 
     var r14 = foo7(1, a); // any => string (+1 overload) [inferences are made for T, but lambda not contextually typed]
->r14 : { (x: any): string; (x: any, y?: any): string; }
->foo7(1, a) : { (x: any): string; (x: any, y?: any): string; }
+>r14 : { (x: {}): string; (x: {}, y?: {}): string; }
+>foo7(1, a) : { (x: {}): string; (x: {}, y?: {}): string; }
 >foo7 : <T>(x: T, cb: { (x: T): string; (x: T, y?: T): string; }) => { (x: T): string; (x: T, y?: T): string; }
 >1 : 1
 >a : { <T>(x: T): string; <T>(x: number): T; }
diff --git a/tests/baselines/reference/genericCallWithOverloadedFunctionTypedArguments2.errors.txt b/tests/baselines/reference/genericCallWithOverloadedFunctionTypedArguments2.errors.txt
index 32fe6a09344..9ee5e6f0cfe 100644
--- a/tests/baselines/reference/genericCallWithOverloadedFunctionTypedArguments2.errors.txt
+++ b/tests/baselines/reference/genericCallWithOverloadedFunctionTypedArguments2.errors.txt
@@ -1,4 +1,4 @@
-tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithOverloadedFunctionTypedArguments2.ts(28,20): error TS2345: Argument of type '<T>(x: T, y: T) => string' is not assignable to parameter of type '{ (x: any): string; (x: any, y?: any): string; }'.
+tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithOverloadedFunctionTypedArguments2.ts(28,20): error TS2345: Argument of type '<T>(x: T, y: T) => string' is not assignable to parameter of type '{ (x: {}): string; (x: {}, y?: {}): string; }'.
 
 
 ==== tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithOverloadedFunctionTypedArguments2.ts (1 errors) ====
@@ -31,7 +31,7 @@ tests/cases/conformance/types/typeRelationships/typeInference/genericCallWithOve
     
         var r10 = foo6(<T>(x: T, y: T) => ''); // error
                        ~~~~~~~~~~~~~~~~~~~~~
-!!! error TS2345: Argument of type '<T>(x: T, y: T) => string' is not assignable to parameter of type '{ (x: any): string; (x: any, y?: any): string; }'.
+!!! error TS2345: Argument of type '<T>(x: T, y: T) => string' is not assignable to parameter of type '{ (x: {}): string; (x: {}, y?: {}): string; }'.
     
         function foo7<T>(x:T, cb: { (x: T): string; (x: T, y?: T): string }) {
             return cb;
diff --git a/tests/baselines/reference/genericCallWithOverloadedFunctionTypedArguments2.types b/tests/baselines/reference/genericCallWithOverloadedFunctionTypedArguments2.types
index da52da85044..7bc9be99a59 100644
--- a/tests/baselines/reference/genericCallWithOverloadedFunctionTypedArguments2.types
+++ b/tests/baselines/reference/genericCallWithOverloadedFunctionTypedArguments2.types
@@ -55,8 +55,8 @@ module GenericParameter {
     }
 
     var r6 = foo5(<T>(x: T) => x); // ok
->r6 : { (x: any): string; (x: number): any; }
->foo5(<T>(x: T) => x) : { (x: any): string; (x: number): any; }
+>r6 : { (x: {}): string; (x: number): {}; }
+>foo5(<T>(x: T) => x) : { (x: {}): string; (x: number): {}; }
 >foo5 : <T>(cb: { (x: T): string; (x: number): T; }) => { (x: T): string; (x: number): T; }
 ><T>(x: T) => x : <T>(x: T) => T
 >T : T
@@ -109,8 +109,8 @@ module GenericParameter {
     }
 
     var r13 = foo7(1, <T>(x: T) => x); // ok
->r13 : { (x: any): string; (x: any, y?: any): string; }
->foo7(1, <T>(x: T) => x) : { (x: any): string; (x: any, y?: any): string; }
+>r13 : { (x: {}): string; (x: {}, y?: {}): string; }
+>foo7(1, <T>(x: T) => x) : { (x: {}): string; (x: {}, y?: {}): string; }
 >foo7 : <T>(x: T, cb: { (x: T): string; (x: T, y?: T): string; }) => { (x: T): string; (x: T, y?: T): string; }
 >1 : 1
 ><T>(x: T) => x : <T>(x: T) => T
@@ -129,8 +129,8 @@ module GenericParameter {
 >T : T
 
     var r14 = foo7(1, a); // ok
->r14 : { (x: any): string; (x: any, y?: any): string; }
->foo7(1, a) : { (x: any): string; (x: any, y?: any): string; }
+>r14 : { (x: {}): string; (x: {}, y?: {}): string; }
+>foo7(1, a) : { (x: {}): string; (x: {}, y?: {}): string; }
 >foo7 : <T>(x: T, cb: { (x: T): string; (x: T, y?: T): string; }) => { (x: T): string; (x: T, y?: T): string; }
 >1 : 1
 >a : { <T>(x: T): number; <T>(x: number): T; }
diff --git a/tests/baselines/reference/promisePermutations.types b/tests/baselines/reference/promisePermutations.types
index 1b8ec25b639..df057583cc2 100644
--- a/tests/baselines/reference/promisePermutations.types
+++ b/tests/baselines/reference/promisePermutations.types
@@ -1396,8 +1396,8 @@ var r12 = testFunction12(x => x);
 >x : any
 
 var r12a = r12.then(testFunction12, testFunction12, testFunction12); // ok
->r12a : IPromise<any>
->r12.then(testFunction12, testFunction12, testFunction12) : IPromise<any>
+>r12a : IPromise<{}>
+>r12.then(testFunction12, testFunction12, testFunction12) : IPromise<{}>
 >r12.then : { <U>(success?: (value: (x: any) => any) => IPromise<U>, error?: (error: any) => IPromise<U>, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: (x: any) => any) => IPromise<U>, error?: (error: any) => U, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: (x: any) => any) => U, error?: (error: any) => IPromise<U>, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: (x: any) => any) => U, error?: (error: any) => U, progress?: (progress: any) => void): IPromise<U>; }
 >r12 : IPromise<(x: any) => any>
 >then : { <U>(success?: (value: (x: any) => any) => IPromise<U>, error?: (error: any) => IPromise<U>, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: (x: any) => any) => IPromise<U>, error?: (error: any) => U, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: (x: any) => any) => U, error?: (error: any) => IPromise<U>, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: (x: any) => any) => U, error?: (error: any) => U, progress?: (progress: any) => void): IPromise<U>; }
@@ -1414,8 +1414,8 @@ var s12 = testFunction12(x => x);
 >x : any
 
 var s12a = s12.then(testFunction12, testFunction12, testFunction12); // ok
->s12a : IPromise<any>
->s12.then(testFunction12, testFunction12, testFunction12) : IPromise<any>
+>s12a : IPromise<{}>
+>s12.then(testFunction12, testFunction12, testFunction12) : IPromise<{}>
 >s12.then : { <U>(success?: (value: (x: any) => any) => IPromise<U>, error?: (error: any) => IPromise<U>, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: (x: any) => any) => IPromise<U>, error?: (error: any) => U, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: (x: any) => any) => U, error?: (error: any) => IPromise<U>, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: (x: any) => any) => U, error?: (error: any) => U, progress?: (progress: any) => void): IPromise<U>; }
 >s12 : IPromise<(x: any) => any>
 >then : { <U>(success?: (value: (x: any) => any) => IPromise<U>, error?: (error: any) => IPromise<U>, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: (x: any) => any) => IPromise<U>, error?: (error: any) => U, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: (x: any) => any) => U, error?: (error: any) => IPromise<U>, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: (x: any) => any) => U, error?: (error: any) => U, progress?: (progress: any) => void): IPromise<U>; }
@@ -1424,8 +1424,8 @@ var s12a = s12.then(testFunction12, testFunction12, testFunction12); // ok
 >testFunction12 : { <T>(x: T): IPromise<T>; <T>(x: T, y: T): IPromise<T>; }
 
 var s12b = s12.then(testFunction12P, testFunction12P, testFunction12P); // ok
->s12b : IPromise<any>
->s12.then(testFunction12P, testFunction12P, testFunction12P) : IPromise<any>
+>s12b : IPromise<{}>
+>s12.then(testFunction12P, testFunction12P, testFunction12P) : IPromise<{}>
 >s12.then : { <U>(success?: (value: (x: any) => any) => IPromise<U>, error?: (error: any) => IPromise<U>, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: (x: any) => any) => IPromise<U>, error?: (error: any) => U, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: (x: any) => any) => U, error?: (error: any) => IPromise<U>, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: (x: any) => any) => U, error?: (error: any) => U, progress?: (progress: any) => void): IPromise<U>; }
 >s12 : IPromise<(x: any) => any>
 >then : { <U>(success?: (value: (x: any) => any) => IPromise<U>, error?: (error: any) => IPromise<U>, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: (x: any) => any) => IPromise<U>, error?: (error: any) => U, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: (x: any) => any) => U, error?: (error: any) => IPromise<U>, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: (x: any) => any) => U, error?: (error: any) => U, progress?: (progress: any) => void): IPromise<U>; }
@@ -1434,8 +1434,8 @@ var s12b = s12.then(testFunction12P, testFunction12P, testFunction12P); // ok
 >testFunction12P : { <T>(x: T): IPromise<T>; <T>(x: T, y: T): Promise<T>; }
 
 var s12c = s12.then(testFunction12P, testFunction12, testFunction12); // ok
->s12c : IPromise<any>
->s12.then(testFunction12P, testFunction12, testFunction12) : IPromise<any>
+>s12c : IPromise<{}>
+>s12.then(testFunction12P, testFunction12, testFunction12) : IPromise<{}>
 >s12.then : { <U>(success?: (value: (x: any) => any) => IPromise<U>, error?: (error: any) => IPromise<U>, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: (x: any) => any) => IPromise<U>, error?: (error: any) => U, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: (x: any) => any) => U, error?: (error: any) => IPromise<U>, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: (x: any) => any) => U, error?: (error: any) => U, progress?: (progress: any) => void): IPromise<U>; }
 >s12 : IPromise<(x: any) => any>
 >then : { <U>(success?: (value: (x: any) => any) => IPromise<U>, error?: (error: any) => IPromise<U>, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: (x: any) => any) => IPromise<U>, error?: (error: any) => U, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: (x: any) => any) => U, error?: (error: any) => IPromise<U>, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: (x: any) => any) => U, error?: (error: any) => U, progress?: (progress: any) => void): IPromise<U>; }
diff --git a/tests/baselines/reference/promisePermutations2.types b/tests/baselines/reference/promisePermutations2.types
index 0e3af43b86f..28a74aa7d77 100644
--- a/tests/baselines/reference/promisePermutations2.types
+++ b/tests/baselines/reference/promisePermutations2.types
@@ -1349,8 +1349,8 @@ var r12 = testFunction12(x => x);
 >x : any
 
 var r12a = r12.then(testFunction12, testFunction12, testFunction12); // ok
->r12a : IPromise<any>
->r12.then(testFunction12, testFunction12, testFunction12) : IPromise<any>
+>r12a : IPromise<{}>
+>r12.then(testFunction12, testFunction12, testFunction12) : IPromise<{}>
 >r12.then : { <U>(success?: (value: (x: any) => any) => IPromise<U>, error?: (error: any) => IPromise<U>, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: (x: any) => any) => IPromise<U>, error?: (error: any) => U, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: (x: any) => any) => U, error?: (error: any) => IPromise<U>, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: (x: any) => any) => U, error?: (error: any) => U, progress?: (progress: any) => void): IPromise<U>; }
 >r12 : IPromise<(x: any) => any>
 >then : { <U>(success?: (value: (x: any) => any) => IPromise<U>, error?: (error: any) => IPromise<U>, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: (x: any) => any) => IPromise<U>, error?: (error: any) => U, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: (x: any) => any) => U, error?: (error: any) => IPromise<U>, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: (x: any) => any) => U, error?: (error: any) => U, progress?: (progress: any) => void): IPromise<U>; }
@@ -1367,8 +1367,8 @@ var s12 = testFunction12(x => x);
 >x : any
 
 var s12a = s12.then(testFunction12, testFunction12, testFunction12); // ok
->s12a : IPromise<any>
->s12.then(testFunction12, testFunction12, testFunction12) : IPromise<any>
+>s12a : IPromise<{}>
+>s12.then(testFunction12, testFunction12, testFunction12) : IPromise<{}>
 >s12.then : { <U>(success?: (value: (x: any) => any) => IPromise<U>, error?: (error: any) => IPromise<U>, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: (x: any) => any) => IPromise<U>, error?: (error: any) => U, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: (x: any) => any) => U, error?: (error: any) => IPromise<U>, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: (x: any) => any) => U, error?: (error: any) => U, progress?: (progress: any) => void): IPromise<U>; }
 >s12 : IPromise<(x: any) => any>
 >then : { <U>(success?: (value: (x: any) => any) => IPromise<U>, error?: (error: any) => IPromise<U>, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: (x: any) => any) => IPromise<U>, error?: (error: any) => U, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: (x: any) => any) => U, error?: (error: any) => IPromise<U>, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: (x: any) => any) => U, error?: (error: any) => U, progress?: (progress: any) => void): IPromise<U>; }
@@ -1377,8 +1377,8 @@ var s12a = s12.then(testFunction12, testFunction12, testFunction12); // ok
 >testFunction12 : { <T>(x: T): IPromise<T>; <T>(x: T, y: T): IPromise<T>; }
 
 var s12b = s12.then(testFunction12P, testFunction12P, testFunction12P); // ok
->s12b : IPromise<any>
->s12.then(testFunction12P, testFunction12P, testFunction12P) : IPromise<any>
+>s12b : IPromise<{}>
+>s12.then(testFunction12P, testFunction12P, testFunction12P) : IPromise<{}>
 >s12.then : { <U>(success?: (value: (x: any) => any) => IPromise<U>, error?: (error: any) => IPromise<U>, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: (x: any) => any) => IPromise<U>, error?: (error: any) => U, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: (x: any) => any) => U, error?: (error: any) => IPromise<U>, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: (x: any) => any) => U, error?: (error: any) => U, progress?: (progress: any) => void): IPromise<U>; }
 >s12 : IPromise<(x: any) => any>
 >then : { <U>(success?: (value: (x: any) => any) => IPromise<U>, error?: (error: any) => IPromise<U>, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: (x: any) => any) => IPromise<U>, error?: (error: any) => U, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: (x: any) => any) => U, error?: (error: any) => IPromise<U>, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: (x: any) => any) => U, error?: (error: any) => U, progress?: (progress: any) => void): IPromise<U>; }
@@ -1387,8 +1387,8 @@ var s12b = s12.then(testFunction12P, testFunction12P, testFunction12P); // ok
 >testFunction12P : { <T>(x: T): IPromise<T>; <T>(x: T, y: T): Promise<T>; }
 
 var s12c = s12.then(testFunction12P, testFunction12, testFunction12); // ok
->s12c : IPromise<any>
->s12.then(testFunction12P, testFunction12, testFunction12) : IPromise<any>
+>s12c : IPromise<{}>
+>s12.then(testFunction12P, testFunction12, testFunction12) : IPromise<{}>
 >s12.then : { <U>(success?: (value: (x: any) => any) => IPromise<U>, error?: (error: any) => IPromise<U>, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: (x: any) => any) => IPromise<U>, error?: (error: any) => U, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: (x: any) => any) => U, error?: (error: any) => IPromise<U>, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: (x: any) => any) => U, error?: (error: any) => U, progress?: (progress: any) => void): IPromise<U>; }
 >s12 : IPromise<(x: any) => any>
 >then : { <U>(success?: (value: (x: any) => any) => IPromise<U>, error?: (error: any) => IPromise<U>, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: (x: any) => any) => IPromise<U>, error?: (error: any) => U, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: (x: any) => any) => U, error?: (error: any) => IPromise<U>, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: (x: any) => any) => U, error?: (error: any) => U, progress?: (progress: any) => void): IPromise<U>; }
diff --git a/tests/baselines/reference/promisePermutations3.errors.txt b/tests/baselines/reference/promisePermutations3.errors.txt
index 8e99b92d53a..e995c4f1d38 100644
--- a/tests/baselines/reference/promisePermutations3.errors.txt
+++ b/tests/baselines/reference/promisePermutations3.errors.txt
@@ -66,8 +66,8 @@ tests/cases/compiler/promisePermutations3.ts(159,21): error TS2345: Argument of
         Types of parameters 'onfulfilled' and 'success' are incompatible.
           Types of parameters 'value' and 'value' are incompatible.
             Type 'number' is not assignable to type 'string'.
-tests/cases/compiler/promisePermutations3.ts(165,21): error TS2345: Argument of type '{ <T>(x: T): IPromise<T>; <T>(x: T, y: T): Promise<T>; }' is not assignable to parameter of type '(value: (x: any) => any) => Promise<any>'.
-  Type 'IPromise<any>' is not assignable to type 'Promise<any>'.
+tests/cases/compiler/promisePermutations3.ts(165,21): error TS2345: Argument of type '{ <T>(x: T): IPromise<T>; <T>(x: T, y: T): Promise<T>; }' is not assignable to parameter of type '(value: (x: any) => any) => Promise<{}>'.
+  Type 'IPromise<any>' is not assignable to type 'Promise<{}>'.
     Property 'catch' is missing in type 'IPromise<any>'.
 
 
@@ -340,7 +340,7 @@ tests/cases/compiler/promisePermutations3.ts(165,21): error TS2345: Argument of
     var s12a = s12.then(testFunction12, testFunction12, testFunction12); // ok
     var s12b = s12.then(testFunction12P, testFunction12P, testFunction12P); // ok
                         ~~~~~~~~~~~~~~~
-!!! error TS2345: Argument of type '{ <T>(x: T): IPromise<T>; <T>(x: T, y: T): Promise<T>; }' is not assignable to parameter of type '(value: (x: any) => any) => Promise<any>'.
-!!! error TS2345:   Type 'IPromise<any>' is not assignable to type 'Promise<any>'.
+!!! error TS2345: Argument of type '{ <T>(x: T): IPromise<T>; <T>(x: T, y: T): Promise<T>; }' is not assignable to parameter of type '(value: (x: any) => any) => Promise<{}>'.
+!!! error TS2345:   Type 'IPromise<any>' is not assignable to type 'Promise<{}>'.
 !!! error TS2345:     Property 'catch' is missing in type 'IPromise<any>'.
     var s12c = s12.then(testFunction12P, testFunction12, testFunction12); // ok
\ No newline at end of file
diff --git a/tests/baselines/reference/promisePermutations3.types b/tests/baselines/reference/promisePermutations3.types
index 34eff1806d6..ab6390ae77d 100644
--- a/tests/baselines/reference/promisePermutations3.types
+++ b/tests/baselines/reference/promisePermutations3.types
@@ -1349,8 +1349,8 @@ var r12 = testFunction12(x => x);
 >x : any
 
 var r12a = r12.then(testFunction12, testFunction12, testFunction12); // ok
->r12a : IPromise<IPromise<any>>
->r12.then(testFunction12, testFunction12, testFunction12) : IPromise<IPromise<any>>
+>r12a : IPromise<IPromise<{}>>
+>r12.then(testFunction12, testFunction12, testFunction12) : IPromise<IPromise<{}>>
 >r12.then : <U>(success?: (value: (x: any) => any) => U, error?: (error: any) => U, progress?: (progress: any) => void) => IPromise<U>
 >r12 : IPromise<(x: any) => any>
 >then : <U>(success?: (value: (x: any) => any) => U, error?: (error: any) => U, progress?: (progress: any) => void) => IPromise<U>
@@ -1367,8 +1367,8 @@ var s12 = testFunction12(x => x);
 >x : any
 
 var s12a = s12.then(testFunction12, testFunction12, testFunction12); // ok
->s12a : IPromise<IPromise<any>>
->s12.then(testFunction12, testFunction12, testFunction12) : IPromise<IPromise<any>>
+>s12a : IPromise<IPromise<{}>>
+>s12.then(testFunction12, testFunction12, testFunction12) : IPromise<IPromise<{}>>
 >s12.then : <U>(success?: (value: (x: any) => any) => U, error?: (error: any) => U, progress?: (progress: any) => void) => IPromise<U>
 >s12 : IPromise<(x: any) => any>
 >then : <U>(success?: (value: (x: any) => any) => U, error?: (error: any) => U, progress?: (progress: any) => void) => IPromise<U>
@@ -1387,8 +1387,8 @@ var s12b = s12.then(testFunction12P, testFunction12P, testFunction12P); // ok
 >testFunction12P : { <T>(x: T): IPromise<T>; <T>(x: T, y: T): Promise<T>; }
 
 var s12c = s12.then(testFunction12P, testFunction12, testFunction12); // ok
->s12c : IPromise<IPromise<any>>
->s12.then(testFunction12P, testFunction12, testFunction12) : IPromise<IPromise<any>>
+>s12c : IPromise<IPromise<{}>>
+>s12.then(testFunction12P, testFunction12, testFunction12) : IPromise<IPromise<{}>>
 >s12.then : <U>(success?: (value: (x: any) => any) => U, error?: (error: any) => U, progress?: (progress: any) => void) => IPromise<U>
 >s12 : IPromise<(x: any) => any>
 >then : <U>(success?: (value: (x: any) => any) => U, error?: (error: any) => U, progress?: (progress: any) => void) => IPromise<U>

From 414f165df0ec099723a61d5702ca9aaf50dcbe3c Mon Sep 17 00:00:00 2001
From: Anders Hejlsberg <andersh@microsoft.com>
Date: Mon, 23 Oct 2017 12:36:44 -0700
Subject: [PATCH 3/7] Add tests

---
 .../reference/genericFunctionParameters.js    | 34 ++++++++
 .../genericFunctionParameters.symbols         | 72 +++++++++++++++++
 .../reference/genericFunctionParameters.types | 81 +++++++++++++++++++
 .../genericFunctionParameters.ts              | 15 ++++
 4 files changed, 202 insertions(+)
 create mode 100644 tests/baselines/reference/genericFunctionParameters.js
 create mode 100644 tests/baselines/reference/genericFunctionParameters.symbols
 create mode 100644 tests/baselines/reference/genericFunctionParameters.types
 create mode 100644 tests/cases/conformance/types/typeRelationships/typeInference/genericFunctionParameters.ts

diff --git a/tests/baselines/reference/genericFunctionParameters.js b/tests/baselines/reference/genericFunctionParameters.js
new file mode 100644
index 00000000000..55f4196e77b
--- /dev/null
+++ b/tests/baselines/reference/genericFunctionParameters.js
@@ -0,0 +1,34 @@
+//// [genericFunctionParameters.ts]
+declare function f1<T>(cb: <S>(x: S) => T): T;
+declare function f2<T>(cb: <S extends number>(x: S) => T): T;
+declare function f3<T>(cb: <S extends Array<S>>(x: S) => T): T;
+
+let x1 = f1(x => x);  // {}
+let x2 = f2(x => x);  // number
+let x3 = f3(x => x);  // Array<any>
+
+// Repro from #19345
+
+declare const s: <R>(go: <S>(ops: { init(): S; }) => R) => R;
+const x = s(a => a.init());  // x is any, should have been {}
+
+
+//// [genericFunctionParameters.js]
+"use strict";
+var x1 = f1(function (x) { return x; }); // {}
+var x2 = f2(function (x) { return x; }); // number
+var x3 = f3(function (x) { return x; }); // Array<any>
+var x = s(function (a) { return a.init(); }); // x is any, should have been {}
+
+
+//// [genericFunctionParameters.d.ts]
+declare function f1<T>(cb: <S>(x: S) => T): T;
+declare function f2<T>(cb: <S extends number>(x: S) => T): T;
+declare function f3<T>(cb: <S extends Array<S>>(x: S) => T): T;
+declare let x1: {};
+declare let x2: number;
+declare let x3: any[];
+declare const s: <R>(go: <S>(ops: {
+    init(): S;
+}) => R) => R;
+declare const x: {};
diff --git a/tests/baselines/reference/genericFunctionParameters.symbols b/tests/baselines/reference/genericFunctionParameters.symbols
new file mode 100644
index 00000000000..c5955949289
--- /dev/null
+++ b/tests/baselines/reference/genericFunctionParameters.symbols
@@ -0,0 +1,72 @@
+=== tests/cases/conformance/types/typeRelationships/typeInference/genericFunctionParameters.ts ===
+declare function f1<T>(cb: <S>(x: S) => T): T;
+>f1 : Symbol(f1, Decl(genericFunctionParameters.ts, 0, 0))
+>T : Symbol(T, Decl(genericFunctionParameters.ts, 0, 20))
+>cb : Symbol(cb, Decl(genericFunctionParameters.ts, 0, 23))
+>S : Symbol(S, Decl(genericFunctionParameters.ts, 0, 28))
+>x : Symbol(x, Decl(genericFunctionParameters.ts, 0, 31))
+>S : Symbol(S, Decl(genericFunctionParameters.ts, 0, 28))
+>T : Symbol(T, Decl(genericFunctionParameters.ts, 0, 20))
+>T : Symbol(T, Decl(genericFunctionParameters.ts, 0, 20))
+
+declare function f2<T>(cb: <S extends number>(x: S) => T): T;
+>f2 : Symbol(f2, Decl(genericFunctionParameters.ts, 0, 46))
+>T : Symbol(T, Decl(genericFunctionParameters.ts, 1, 20))
+>cb : Symbol(cb, Decl(genericFunctionParameters.ts, 1, 23))
+>S : Symbol(S, Decl(genericFunctionParameters.ts, 1, 28))
+>x : Symbol(x, Decl(genericFunctionParameters.ts, 1, 46))
+>S : Symbol(S, Decl(genericFunctionParameters.ts, 1, 28))
+>T : Symbol(T, Decl(genericFunctionParameters.ts, 1, 20))
+>T : Symbol(T, Decl(genericFunctionParameters.ts, 1, 20))
+
+declare function f3<T>(cb: <S extends Array<S>>(x: S) => T): T;
+>f3 : Symbol(f3, Decl(genericFunctionParameters.ts, 1, 61))
+>T : Symbol(T, Decl(genericFunctionParameters.ts, 2, 20))
+>cb : Symbol(cb, Decl(genericFunctionParameters.ts, 2, 23))
+>S : Symbol(S, Decl(genericFunctionParameters.ts, 2, 28))
+>Array : Symbol(Array, Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --))
+>S : Symbol(S, Decl(genericFunctionParameters.ts, 2, 28))
+>x : Symbol(x, Decl(genericFunctionParameters.ts, 2, 48))
+>S : Symbol(S, Decl(genericFunctionParameters.ts, 2, 28))
+>T : Symbol(T, Decl(genericFunctionParameters.ts, 2, 20))
+>T : Symbol(T, Decl(genericFunctionParameters.ts, 2, 20))
+
+let x1 = f1(x => x);  // {}
+>x1 : Symbol(x1, Decl(genericFunctionParameters.ts, 4, 3))
+>f1 : Symbol(f1, Decl(genericFunctionParameters.ts, 0, 0))
+>x : Symbol(x, Decl(genericFunctionParameters.ts, 4, 12))
+>x : Symbol(x, Decl(genericFunctionParameters.ts, 4, 12))
+
+let x2 = f2(x => x);  // number
+>x2 : Symbol(x2, Decl(genericFunctionParameters.ts, 5, 3))
+>f2 : Symbol(f2, Decl(genericFunctionParameters.ts, 0, 46))
+>x : Symbol(x, Decl(genericFunctionParameters.ts, 5, 12))
+>x : Symbol(x, Decl(genericFunctionParameters.ts, 5, 12))
+
+let x3 = f3(x => x);  // Array<any>
+>x3 : Symbol(x3, Decl(genericFunctionParameters.ts, 6, 3))
+>f3 : Symbol(f3, Decl(genericFunctionParameters.ts, 1, 61))
+>x : Symbol(x, Decl(genericFunctionParameters.ts, 6, 12))
+>x : Symbol(x, Decl(genericFunctionParameters.ts, 6, 12))
+
+// Repro from #19345
+
+declare const s: <R>(go: <S>(ops: { init(): S; }) => R) => R;
+>s : Symbol(s, Decl(genericFunctionParameters.ts, 10, 13))
+>R : Symbol(R, Decl(genericFunctionParameters.ts, 10, 18))
+>go : Symbol(go, Decl(genericFunctionParameters.ts, 10, 21))
+>S : Symbol(S, Decl(genericFunctionParameters.ts, 10, 26))
+>ops : Symbol(ops, Decl(genericFunctionParameters.ts, 10, 29))
+>init : Symbol(init, Decl(genericFunctionParameters.ts, 10, 35))
+>S : Symbol(S, Decl(genericFunctionParameters.ts, 10, 26))
+>R : Symbol(R, Decl(genericFunctionParameters.ts, 10, 18))
+>R : Symbol(R, Decl(genericFunctionParameters.ts, 10, 18))
+
+const x = s(a => a.init());  // x is any, should have been {}
+>x : Symbol(x, Decl(genericFunctionParameters.ts, 11, 5))
+>s : Symbol(s, Decl(genericFunctionParameters.ts, 10, 13))
+>a : Symbol(a, Decl(genericFunctionParameters.ts, 11, 12))
+>a.init : Symbol(init, Decl(genericFunctionParameters.ts, 10, 35))
+>a : Symbol(a, Decl(genericFunctionParameters.ts, 11, 12))
+>init : Symbol(init, Decl(genericFunctionParameters.ts, 10, 35))
+
diff --git a/tests/baselines/reference/genericFunctionParameters.types b/tests/baselines/reference/genericFunctionParameters.types
new file mode 100644
index 00000000000..3ae51c83e12
--- /dev/null
+++ b/tests/baselines/reference/genericFunctionParameters.types
@@ -0,0 +1,81 @@
+=== tests/cases/conformance/types/typeRelationships/typeInference/genericFunctionParameters.ts ===
+declare function f1<T>(cb: <S>(x: S) => T): T;
+>f1 : <T>(cb: <S>(x: S) => T) => T
+>T : T
+>cb : <S>(x: S) => T
+>S : S
+>x : S
+>S : S
+>T : T
+>T : T
+
+declare function f2<T>(cb: <S extends number>(x: S) => T): T;
+>f2 : <T>(cb: <S extends number>(x: S) => T) => T
+>T : T
+>cb : <S extends number>(x: S) => T
+>S : S
+>x : S
+>S : S
+>T : T
+>T : T
+
+declare function f3<T>(cb: <S extends Array<S>>(x: S) => T): T;
+>f3 : <T>(cb: <S extends S[]>(x: S) => T) => T
+>T : T
+>cb : <S extends S[]>(x: S) => T
+>S : S
+>Array : T[]
+>S : S
+>x : S
+>S : S
+>T : T
+>T : T
+
+let x1 = f1(x => x);  // {}
+>x1 : {}
+>f1(x => x) : {}
+>f1 : <T>(cb: <S>(x: S) => T) => T
+>x => x : <S>(x: S) => S
+>x : S
+>x : S
+
+let x2 = f2(x => x);  // number
+>x2 : number
+>f2(x => x) : number
+>f2 : <T>(cb: <S extends number>(x: S) => T) => T
+>x => x : <S extends number>(x: S) => S
+>x : S
+>x : S
+
+let x3 = f3(x => x);  // Array<any>
+>x3 : any[]
+>f3(x => x) : any[]
+>f3 : <T>(cb: <S extends S[]>(x: S) => T) => T
+>x => x : <S extends S[]>(x: S) => S
+>x : S
+>x : S
+
+// Repro from #19345
+
+declare const s: <R>(go: <S>(ops: { init(): S; }) => R) => R;
+>s : <R>(go: <S>(ops: { init(): S; }) => R) => R
+>R : R
+>go : <S>(ops: { init(): S; }) => R
+>S : S
+>ops : { init(): S; }
+>init : () => S
+>S : S
+>R : R
+>R : R
+
+const x = s(a => a.init());  // x is any, should have been {}
+>x : {}
+>s(a => a.init()) : {}
+>s : <R>(go: <S>(ops: { init(): S; }) => R) => R
+>a => a.init() : <S>(a: { init(): S; }) => S
+>a : { init(): S; }
+>a.init() : S
+>a.init : () => S
+>a : { init(): S; }
+>init : () => S
+
diff --git a/tests/cases/conformance/types/typeRelationships/typeInference/genericFunctionParameters.ts b/tests/cases/conformance/types/typeRelationships/typeInference/genericFunctionParameters.ts
new file mode 100644
index 00000000000..e639f6b62b3
--- /dev/null
+++ b/tests/cases/conformance/types/typeRelationships/typeInference/genericFunctionParameters.ts
@@ -0,0 +1,15 @@
+// @strict: true
+// @declaration: true
+
+declare function f1<T>(cb: <S>(x: S) => T): T;
+declare function f2<T>(cb: <S extends number>(x: S) => T): T;
+declare function f3<T>(cb: <S extends Array<S>>(x: S) => T): T;
+
+let x1 = f1(x => x);  // {}
+let x2 = f2(x => x);  // number
+let x3 = f3(x => x);  // Array<any>
+
+// Repro from #19345
+
+declare const s: <R>(go: <S>(ops: { init(): S; }) => R) => R;
+const x = s(a => a.init());  // x is any, should have been {}

From a9ffe0daeb74ed16ec67d6e147a8e2d95baf0e41 Mon Sep 17 00:00:00 2001
From: Andy <anhans@microsoft.com>
Date: Mon, 23 Oct 2017 13:35:53 -0700
Subject: [PATCH 4/7] Update issue_template to ts2.7 (#19422)

---
 issue_template.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/issue_template.md b/issue_template.md
index ddc1d070bc9..dbc021c28ad 100644
--- a/issue_template.md
+++ b/issue_template.md
@@ -3,7 +3,7 @@
 <!-- SUGGESTIONS: See https://github.com/Microsoft/TypeScript-wiki/blob/master/Writing-Good-Design-Proposals.md -->
 
 <!-- Please try to reproduce the issue with `typescript@next`. It may have already been fixed. -->
-**TypeScript Version:**  2.6.0-dev.201xxxxx
+**TypeScript Version:**  2.7.0-dev.201xxxxx
 
 **Code**
 

From f916e38015648a412bc90c748dd08a5ef106a48a Mon Sep 17 00:00:00 2001
From: Andy <anhans@microsoft.com>
Date: Mon, 23 Oct 2017 13:36:36 -0700
Subject: [PATCH 5/7] For @types installing quickfix, only activate for
 implicit-any module (#19394)

---
 src/services/codefixes/fixCannotFindModule.ts         |  1 -
 tests/cases/fourslash/codeFixCannotFindModule.ts      | 11 ++++++++++-
 .../fourslash/codeFixCannotFindModule_notIfMissing.ts | 11 +++++++++++
 3 files changed, 21 insertions(+), 2 deletions(-)
 create mode 100644 tests/cases/fourslash/codeFixCannotFindModule_notIfMissing.ts

diff --git a/src/services/codefixes/fixCannotFindModule.ts b/src/services/codefixes/fixCannotFindModule.ts
index b7fde9d917e..c15ca341cb4 100644
--- a/src/services/codefixes/fixCannotFindModule.ts
+++ b/src/services/codefixes/fixCannotFindModule.ts
@@ -2,7 +2,6 @@
 namespace ts.codefix {
     registerCodeFix({
         errorCodes: [
-            Diagnostics.Cannot_find_module_0.code,
             Diagnostics.Could_not_find_a_declaration_file_for_module_0_1_implicitly_has_an_any_type.code,
         ],
         getCodeActions: context => {
diff --git a/tests/cases/fourslash/codeFixCannotFindModule.ts b/tests/cases/fourslash/codeFixCannotFindModule.ts
index 96e5c201644..d0ace09909e 100644
--- a/tests/cases/fourslash/codeFixCannotFindModule.ts
+++ b/tests/cases/fourslash/codeFixCannotFindModule.ts
@@ -1,11 +1,20 @@
 /// <reference path='fourslash.ts' />
 
-////import * as abs from "abs";
+// @moduleResolution: node
+// @noImplicitAny: true
+
+// @Filename: /node_modules/abs/index.js
+////not read
+
+// @Filename: /a.ts
+/////**/import * as abs from "abs";
 
 test.setTypesRegistry({
     "abs": undefined,
 });
 
+goTo.marker();
+
 verify.codeFixAvailable([{
     description: "Install '@types/abs'",
     commands: [{
diff --git a/tests/cases/fourslash/codeFixCannotFindModule_notIfMissing.ts b/tests/cases/fourslash/codeFixCannotFindModule_notIfMissing.ts
new file mode 100644
index 00000000000..f446c643542
--- /dev/null
+++ b/tests/cases/fourslash/codeFixCannotFindModule_notIfMissing.ts
@@ -0,0 +1,11 @@
+/// <reference path='fourslash.ts' />
+
+// @Filename: /a.ts
+////import * as abs from "abs";
+
+test.setTypesRegistry({
+    "abs": undefined,
+});
+
+// We only give the fix for an implicit-any module, not for a missing module.
+verify.not.codeFixAvailable();

From 159a0a21973cd882fb04d01335aaf7a12bc7ad45 Mon Sep 17 00:00:00 2001
From: Andy <anhans@microsoft.com>
Date: Mon, 23 Oct 2017 13:38:50 -0700
Subject: [PATCH 6/7] Use NodeFlags to detect nodes inside with statements
 instead of climbing ancestors (#17721)

* Use NodeFlags to detect nodes inside with statements instead of climbing ancestors

* Add to ContextFlags
---
 src/compiler/checker.ts | 23 +++++------------------
 src/compiler/parser.ts  |  2 +-
 src/compiler/types.ts   |  3 ++-
 3 files changed, 8 insertions(+), 20 deletions(-)

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 6938ed8d77f..aaaa0ed50b8 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -13440,7 +13440,7 @@ namespace ts {
         // exists. Otherwise, it is the type of the string index signature in T, if one exists.
         function getContextualTypeForObjectLiteralMethod(node: MethodDeclaration): Type {
             Debug.assert(isObjectLiteralMethod(node));
-            if (isInsideWithStatementBody(node)) {
+            if (node.flags & NodeFlags.InWithStatement) {
                 // We cannot answer semantic questions within a with block, do not proceed any further
                 return undefined;
             }
@@ -13559,7 +13559,7 @@ namespace ts {
          * @returns the contextual type of an expression.
          */
         function getContextualType(node: Expression): Type | undefined {
-            if (isInsideWithStatementBody(node)) {
+            if (node.flags & NodeFlags.InWithStatement) {
                 // We cannot answer semantic questions within a with block, do not proceed any further
                 return undefined;
             }
@@ -23124,21 +23124,8 @@ namespace ts {
 
         // Language service support
 
-        function isInsideWithStatementBody(node: Node): boolean {
-            if (node) {
-                while (node.parent) {
-                    if (node.parent.kind === SyntaxKind.WithStatement && (<WithStatement>node.parent).statement === node) {
-                        return true;
-                    }
-                    node = node.parent;
-                }
-            }
-
-            return false;
-        }
-
         function getSymbolsInScope(location: Node, meaning: SymbolFlags): Symbol[] {
-            if (isInsideWithStatementBody(location)) {
+            if (location.flags & NodeFlags.InWithStatement) {
                 // We cannot answer semantic questions within a with block, do not proceed any further
                 return [];
             }
@@ -23438,7 +23425,7 @@ namespace ts {
                 return isExternalModule(<SourceFile>node) ? getMergedSymbol(node.symbol) : undefined;
             }
 
-            if (isInsideWithStatementBody(node)) {
+            if (node.flags & NodeFlags.InWithStatement) {
                 // We cannot answer semantic questions within a with block, do not proceed any further
                 return undefined;
             }
@@ -23546,7 +23533,7 @@ namespace ts {
         }
 
         function getTypeOfNode(node: Node): Type {
-            if (isInsideWithStatementBody(node)) {
+            if (node.flags & NodeFlags.InWithStatement) {
                 // We cannot answer semantic questions within a with block, do not proceed any further
                 return unknownType;
             }
diff --git a/src/compiler/parser.ts b/src/compiler/parser.ts
index e2bae71e6bf..b27d4811ecb 100644
--- a/src/compiler/parser.ts
+++ b/src/compiler/parser.ts
@@ -4724,7 +4724,7 @@ namespace ts {
             parseExpected(SyntaxKind.OpenParenToken);
             node.expression = allowInAnd(parseExpression);
             parseExpected(SyntaxKind.CloseParenToken);
-            node.statement = parseStatement();
+            node.statement = doInsideOfContext(NodeFlags.InWithStatement, parseStatement);
             return finishNode(node);
         }
 
diff --git a/src/compiler/types.ts b/src/compiler/types.ts
index fb59c9eb881..c7030450a75 100644
--- a/src/compiler/types.ts
+++ b/src/compiler/types.ts
@@ -451,6 +451,7 @@ namespace ts {
         /* @internal */
         PossiblyContainsDynamicImport = 1 << 19,
         JSDoc =              1 << 20, // If node was parsed inside jsdoc
+        InWithStatement =    1 << 21, // If any ancestor of node was the `statement` of a WithStatement (not the `expression`)
 
         BlockScoped = Let | Const,
 
@@ -458,7 +459,7 @@ namespace ts {
         ReachabilityAndEmitFlags = ReachabilityCheckFlags | HasAsyncFunctions,
 
         // Parsing context flags
-        ContextFlags = DisallowInContext | YieldContext | DecoratorContext | AwaitContext | JavaScriptFile,
+        ContextFlags = DisallowInContext | YieldContext | DecoratorContext | AwaitContext | JavaScriptFile | InWithStatement,
 
         // Exclude these flags when parsing a Type
         TypeExcludesFlags = YieldContext | AwaitContext,

From fa3ce9fe6ca9c8b8d12ecd35cdceebdd3cec10fc Mon Sep 17 00:00:00 2001
From: Wesley Wigham <wwigham@gmail.com>
Date: Mon, 23 Oct 2017 14:28:20 -0700
Subject: [PATCH 7/7] Fix build break (#19431)

---
 src/compiler/types.ts                              | 2 +-
 tests/baselines/reference/api/tsserverlibrary.d.ts | 2 +-
 tests/baselines/reference/api/typescript.d.ts      | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/compiler/types.ts b/src/compiler/types.ts
index c7030450a75..ff2a33266ed 100644
--- a/src/compiler/types.ts
+++ b/src/compiler/types.ts
@@ -451,7 +451,7 @@ namespace ts {
         /* @internal */
         PossiblyContainsDynamicImport = 1 << 19,
         JSDoc =              1 << 20, // If node was parsed inside jsdoc
-        InWithStatement =    1 << 21, // If any ancestor of node was the `statement` of a WithStatement (not the `expression`)
+        /* @internal */ InWithStatement =    1 << 21, // If any ancestor of node was the `statement` of a WithStatement (not the `expression`)
 
         BlockScoped = Let | Const,
 
diff --git a/tests/baselines/reference/api/tsserverlibrary.d.ts b/tests/baselines/reference/api/tsserverlibrary.d.ts
index 62f4f68d148..0f20bfc8687 100644
--- a/tests/baselines/reference/api/tsserverlibrary.d.ts
+++ b/tests/baselines/reference/api/tsserverlibrary.d.ts
@@ -408,7 +408,7 @@ declare namespace ts {
         BlockScoped = 3,
         ReachabilityCheckFlags = 384,
         ReachabilityAndEmitFlags = 1408,
-        ContextFlags = 96256,
+        ContextFlags = 2193408,
         TypeExcludesFlags = 20480,
     }
     enum ModifierFlags {
diff --git a/tests/baselines/reference/api/typescript.d.ts b/tests/baselines/reference/api/typescript.d.ts
index c7c8ba88d72..67a30bcd371 100644
--- a/tests/baselines/reference/api/typescript.d.ts
+++ b/tests/baselines/reference/api/typescript.d.ts
@@ -408,7 +408,7 @@ declare namespace ts {
         BlockScoped = 3,
         ReachabilityCheckFlags = 384,
         ReachabilityAndEmitFlags = 1408,
-        ContextFlags = 96256,
+        ContextFlags = 2193408,
         TypeExcludesFlags = 20480,
     }
     enum ModifierFlags {