Assign and instantiate contextual this type if not present

src/compiler/checker.ts

@@ -4785,9 +4785,6 @@ namespace ts {
 
         function getThisTypeOfSignature(signature: Signature): Type | undefined {
             if (signature.thisParameter) {
-                if (signature.mapper) {
-                    signature = instantiateSignature(signature, signature.mapper);
-                }
                 return getTypeOfSymbol(signature.thisParameter);
             }
         }
@@ -9085,15 +9082,15 @@ namespace ts {
                         return getInferredClassType(classSymbol);
                     }
                 }
-                const type = getContextuallyTypedThisType(container);
-                if (type) {
-                    return type;
-                }
 
                 const thisType = getThisTypeOfDeclaration(container);
                 if (thisType) {
                     return thisType;
                 }
+                const type = getContextuallyTypedThisType(container);
+                if (type) {
+                    return type;
+                }
             }
             if (isClassLike(container.parent)) {
                 const symbol = getSymbolOfNode(container.parent);
@@ -12277,8 +12274,10 @@ namespace ts {
         function assignContextualParameterTypes(signature: Signature, context: Signature, mapper: TypeMapper) {
             const len = signature.parameters.length - (signature.hasRestParameter ? 1 : 0);
             if (context.thisParameter) {
-                // save the mapper in case we need to type `this` later
-                context.mapper = mapper;
+                if (!signature.thisParameter) {
+                    signature.thisParameter = createTransientSymbol(context.thisParameter, undefined);
+                }
+                assignTypeToParameterAndFixTypeParameters(signature.thisParameter, getTypeOfSymbol(context.thisParameter), mapper);
             }
             for (let i = 0; i < len; i++) {
                 const parameter = signature.parameters[i];

tests/baselines/reference/instantiateContextuallyTypedGenericThis.js

@@ -2,7 +2,7 @@
 interface JQuery {
     each<T>(
         collection: T[], callback: (this: T, dit: T) => T
-    ): any;
+    ): T[];
 }
 
 let $: JQuery;

tests/baselines/reference/instantiateContextuallyTypedGenericThis.symbols

@@ -16,7 +16,8 @@ interface JQuery {
 >T : Symbol(T, Decl(instantiateContextuallyTypedGenericThis.ts, 1, 9))
 >T : Symbol(T, Decl(instantiateContextuallyTypedGenericThis.ts, 1, 9))
 
-    ): any;
+    ): T[];
+>T : Symbol(T, Decl(instantiateContextuallyTypedGenericThis.ts, 1, 9))
 }
 
 let $: JQuery;
@@ -38,6 +39,7 @@ $.each(lines, function(dit) {
 >dit : Symbol(dit, Decl(instantiateContextuallyTypedGenericThis.ts, 8, 23))
 >charAt : Symbol(String.charAt, Decl(lib.d.ts, --, --))
 >this.charAt : Symbol(String.charAt, Decl(lib.d.ts, --, --))
+>this : Symbol(this, Decl(instantiateContextuallyTypedGenericThis.ts, 2, 36))
 >charAt : Symbol(String.charAt, Decl(lib.d.ts, --, --))
 
 });

tests/baselines/reference/instantiateContextuallyTypedGenericThis.types

@@ -3,7 +3,7 @@ interface JQuery {
 >JQuery : JQuery
 
     each<T>(
->each : <T>(collection: T[], callback: (this: T, dit: T) => T) => any
+>each : <T>(collection: T[], callback: (this: T, dit: T) => T) => T[]
 >T : T
 
         collection: T[], callback: (this: T, dit: T) => T
@@ -16,7 +16,8 @@ interface JQuery {
 >T : T
 >T : T
 
-    ): any;
+    ): T[];
+>T : T
 }
 
 let $: JQuery;
@@ -27,12 +28,12 @@ let lines: string[];
 >lines : string[]
 
 $.each(lines, function(dit) {
->$.each(lines, function(dit) {    return dit.charAt(0) + this.charAt(1);}) : any
->$.each : <T>(collection: T[], callback: (this: T, dit: T) => T) => any
+>$.each(lines, function(dit) {    return dit.charAt(0) + this.charAt(1);}) : string[]
+>$.each : <T>(collection: T[], callback: (this: T, dit: T) => T) => T[]
 >$ : JQuery
->each : <T>(collection: T[], callback: (this: T, dit: T) => T) => any
+>each : <T>(collection: T[], callback: (this: T, dit: T) => T) => T[]
 >lines : string[]
->function(dit) {    return dit.charAt(0) + this.charAt(1);} : (dit: string) => string
+>function(dit) {    return dit.charAt(0) + this.charAt(1);} : (this: string, dit: string) => string
 >dit : string
 
     return dit.charAt(0) + this.charAt(1);

tests/baselines/reference/thisTypeInFunctions.symbols

@@ -135,7 +135,7 @@ let impl: I = {
 
         return this.a;
 >this.a : Symbol(a, Decl(thisTypeInFunctions.ts, 24, 30))
->this : Symbol(, Decl(thisTypeInFunctions.ts, 24, 28))
+>this : Symbol(this, Decl(thisTypeInFunctions.ts, 24, 23))
 >a : Symbol(a, Decl(thisTypeInFunctions.ts, 24, 30))
 
     },
@@ -144,7 +144,7 @@ let impl: I = {
 
         return this.a;
 >this.a : Symbol(I.a, Decl(thisTypeInFunctions.ts, 20, 13))
->this : Symbol(I, Decl(thisTypeInFunctions.ts, 19, 21))
+>this : Symbol(this, Decl(thisTypeInFunctions.ts, 25, 22))
 >a : Symbol(I.a, Decl(thisTypeInFunctions.ts, 20, 13))
 
     },
@@ -153,7 +153,7 @@ let impl: I = {
 
         return this.a;
 >this.a : Symbol(I.a, Decl(thisTypeInFunctions.ts, 20, 13))
->this : Symbol(I, Decl(thisTypeInFunctions.ts, 19, 21))
+>this : Symbol(this, Decl(thisTypeInFunctions.ts, 26, 17))
 >a : Symbol(I.a, Decl(thisTypeInFunctions.ts, 20, 13))
 
     },
@@ -173,7 +173,7 @@ impl.explicitStructural = function() { return this.a; };
 >impl : Symbol(impl, Decl(thisTypeInFunctions.ts, 37, 3))
 >explicitStructural : Symbol(I.explicitStructural, Decl(thisTypeInFunctions.ts, 23, 38))
 >this.a : Symbol(a, Decl(thisTypeInFunctions.ts, 24, 30))
->this : Symbol(, Decl(thisTypeInFunctions.ts, 24, 28))
+>this : Symbol(this, Decl(thisTypeInFunctions.ts, 24, 23))
 >a : Symbol(a, Decl(thisTypeInFunctions.ts, 24, 30))
 
 impl.explicitInterface = function() { return this.a; };
@@ -181,7 +181,7 @@ impl.explicitInterface = function() { return this.a; };
 >impl : Symbol(impl, Decl(thisTypeInFunctions.ts, 37, 3))
 >explicitInterface : Symbol(I.explicitInterface, Decl(thisTypeInFunctions.ts, 24, 50))
 >this.a : Symbol(I.a, Decl(thisTypeInFunctions.ts, 20, 13))
->this : Symbol(I, Decl(thisTypeInFunctions.ts, 19, 21))
+>this : Symbol(this, Decl(thisTypeInFunctions.ts, 25, 22))
 >a : Symbol(I.a, Decl(thisTypeInFunctions.ts, 20, 13))
 
 impl.explicitStructural = () => 12;
@@ -199,7 +199,7 @@ impl.explicitThis = function () { return this.a; };
 >impl : Symbol(impl, Decl(thisTypeInFunctions.ts, 37, 3))
 >explicitThis : Symbol(I.explicitThis, Decl(thisTypeInFunctions.ts, 25, 39))
 >this.a : Symbol(I.a, Decl(thisTypeInFunctions.ts, 20, 13))
->this : Symbol(I, Decl(thisTypeInFunctions.ts, 19, 21))
+>this : Symbol(this, Decl(thisTypeInFunctions.ts, 26, 17))
 >a : Symbol(I.a, Decl(thisTypeInFunctions.ts, 20, 13))
 
 // parameter checking
@@ -536,7 +536,7 @@ c.explicitC = function(m) { return this.n + m };
 >explicitC : Symbol(C.explicitC, Decl(thisTypeInFunctions.ts, 8, 5))
 >m : Symbol(m, Decl(thisTypeInFunctions.ts, 126, 23))
 >this.n : Symbol(C.n, Decl(thisTypeInFunctions.ts, 4, 9))
->this : Symbol(C, Decl(thisTypeInFunctions.ts, 3, 1))
+>this : Symbol(this, Decl(thisTypeInFunctions.ts, 9, 14))
 >n : Symbol(C.n, Decl(thisTypeInFunctions.ts, 4, 9))
 >m : Symbol(m, Decl(thisTypeInFunctions.ts, 126, 23))
 
@@ -546,7 +546,7 @@ c.explicitProperty = function(m) { return this.n + m };
 >explicitProperty : Symbol(C.explicitProperty, Decl(thisTypeInFunctions.ts, 11, 5))
 >m : Symbol(m, Decl(thisTypeInFunctions.ts, 127, 30))
 >this.n : Symbol(n, Decl(thisTypeInFunctions.ts, 12, 28))
->this : Symbol(, Decl(thisTypeInFunctions.ts, 12, 26))
+>this : Symbol(this, Decl(thisTypeInFunctions.ts, 12, 21))
 >n : Symbol(n, Decl(thisTypeInFunctions.ts, 12, 28))
 >m : Symbol(m, Decl(thisTypeInFunctions.ts, 127, 30))
 
@@ -556,7 +556,7 @@ c.explicitThis = function(m) { return this.n + m };
 >explicitThis : Symbol(C.explicitThis, Decl(thisTypeInFunctions.ts, 5, 14))
 >m : Symbol(m, Decl(thisTypeInFunctions.ts, 128, 26))
 >this.n : Symbol(C.n, Decl(thisTypeInFunctions.ts, 4, 9))
->this : Symbol(C, Decl(thisTypeInFunctions.ts, 3, 1))
+>this : Symbol(this, Decl(thisTypeInFunctions.ts, 6, 17))
 >n : Symbol(C.n, Decl(thisTypeInFunctions.ts, 4, 9))
 >m : Symbol(m, Decl(thisTypeInFunctions.ts, 128, 26))
 

tests/baselines/reference/thisTypeInFunctions.types

@@ -132,7 +132,7 @@ function implicitThis(n: number): number {
 let impl: I = {
 >impl : I
 >I : I
->{    a: 12,    explicitVoid2: () => this.a, // ok, this: any because it refers to some outer object (window?)    explicitVoid1() { return 12; },    explicitStructural() {        return this.a;    },    explicitInterface() {        return this.a;    },    explicitThis() {        return this.a;    },} : { a: number; explicitVoid2: () => any; explicitVoid1(): number; explicitStructural(): number; explicitInterface(): number; explicitThis(): number; }
+>{    a: 12,    explicitVoid2: () => this.a, // ok, this: any because it refers to some outer object (window?)    explicitVoid1() { return 12; },    explicitStructural() {        return this.a;    },    explicitInterface() {        return this.a;    },    explicitThis() {        return this.a;    },} : { a: number; explicitVoid2: () => any; explicitVoid1(this: void): number; explicitStructural(this: { a: number; }): number; explicitInterface(this: I): number; explicitThis(this: I): number; }
 
     a: 12,
 >a : number
@@ -146,11 +146,11 @@ let impl: I = {
 >a : any
 
     explicitVoid1() { return 12; },
->explicitVoid1 : () => number
+>explicitVoid1 : (this: void) => number
 >12 : number
 
     explicitStructural() {
->explicitStructural : () => number
+>explicitStructural : (this: { a: number; }) => number
 
         return this.a;
 >this.a : number
@@ -159,7 +159,7 @@ let impl: I = {
 
     },
     explicitInterface() {
->explicitInterface : () => number
+>explicitInterface : (this: I) => number
 
         return this.a;
 >this.a : number
@@ -168,7 +168,7 @@ let impl: I = {
 
     },
     explicitThis() {
->explicitThis : () => number
+>explicitThis : (this: I) => number
 
         return this.a;
 >this.a : number
@@ -178,11 +178,11 @@ let impl: I = {
     },
 }
 impl.explicitVoid1 = function () { return 12; };
->impl.explicitVoid1 = function () { return 12; } : () => number
+>impl.explicitVoid1 = function () { return 12; } : (this: void) => number
 >impl.explicitVoid1 : (this: void) => number
 >impl : I
 >explicitVoid1 : (this: void) => number
->function () { return 12; } : () => number
+>function () { return 12; } : (this: void) => number
 >12 : number
 
 impl.explicitVoid2 = () => 12;
@@ -194,21 +194,21 @@ impl.explicitVoid2 = () => 12;
 >12 : number
 
 impl.explicitStructural = function() { return this.a; };
->impl.explicitStructural = function() { return this.a; } : () => number
+>impl.explicitStructural = function() { return this.a; } : (this: { a: number; }) => number
 >impl.explicitStructural : (this: { a: number; }) => number
 >impl : I
 >explicitStructural : (this: { a: number; }) => number
->function() { return this.a; } : () => number
+>function() { return this.a; } : (this: { a: number; }) => number
 >this.a : number
 >this : { a: number; }
 >a : number
 
 impl.explicitInterface = function() { return this.a; };
->impl.explicitInterface = function() { return this.a; } : () => number
+>impl.explicitInterface = function() { return this.a; } : (this: I) => number
 >impl.explicitInterface : (this: I) => number
 >impl : I
 >explicitInterface : (this: I) => number
->function() { return this.a; } : () => number
+>function() { return this.a; } : (this: I) => number
 >this.a : number
 >this : I
 >a : number
@@ -230,11 +230,11 @@ impl.explicitInterface = () => 12;
 >12 : number
 
 impl.explicitThis = function () { return this.a; };
->impl.explicitThis = function () { return this.a; } : () => number
+>impl.explicitThis = function () { return this.a; } : (this: I) => number
 >impl.explicitThis : (this: I) => number
 >impl : I
 >explicitThis : (this: I) => number
->function () { return this.a; } : () => number
+>function () { return this.a; } : (this: I) => number
 >this.a : number
 >this : I
 >a : number
@@ -433,7 +433,7 @@ let unboundToSpecified: (this: { y: number }, x: number) => number = x => x + th
 >this : { y: number; }
 >y : number
 >x : number
->x => x + this.y : (x: number) => any
+>x => x + this.y : (this: { y: number; }, x: number) => any
 >x : number
 >x + this.y : any
 >x : number
@@ -472,7 +472,7 @@ let specifiedLambda: (this: void, x: number) => number = x => x + 12;
 >specifiedLambda : (this: void, x: number) => number
 >this : void
 >x : number
->x => x + 12 : (x: number) => number
+>x => x + 12 : (this: void, x: number) => number
 >x : number
 >x + 12 : number
 >x : number
@@ -560,40 +560,40 @@ c.explicitProperty = reconstructed.explicitProperty;
 
 // lambdas are assignable to anything
 c.explicitC = m => m;
->c.explicitC = m => m : (m: number) => number
+>c.explicitC = m => m : (this: C, m: number) => number
 >c.explicitC : (this: C, m: number) => number
 >c : C
 >explicitC : (this: C, m: number) => number
->m => m : (m: number) => number
+>m => m : (this: C, m: number) => number
 >m : number
 >m : number
 
 c.explicitThis = m => m;
->c.explicitThis = m => m : (m: number) => number
+>c.explicitThis = m => m : (this: C, m: number) => number
 >c.explicitThis : (this: C, m: number) => number
 >c : C
 >explicitThis : (this: C, m: number) => number
->m => m : (m: number) => number
+>m => m : (this: C, m: number) => number
 >m : number
 >m : number
 
 c.explicitProperty = m => m;
->c.explicitProperty = m => m : (m: number) => number
+>c.explicitProperty = m => m : (this: { n: number; }, m: number) => number
 >c.explicitProperty : (this: { n: number; }, m: number) => number
 >c : C
 >explicitProperty : (this: { n: number; }, m: number) => number
->m => m : (m: number) => number
+>m => m : (this: { n: number; }, m: number) => number
 >m : number
 >m : number
 
 // this inside lambdas refer to outer scope
 // the outer-scoped lambda at top-level is still just `any`
 c.explicitC = m => m + this.n;
->c.explicitC = m => m + this.n : (m: number) => any
+>c.explicitC = m => m + this.n : (this: C, m: number) => any
 >c.explicitC : (this: C, m: number) => number
 >c : C
 >explicitC : (this: C, m: number) => number
->m => m + this.n : (m: number) => any
+>m => m + this.n : (this: C, m: number) => any
 >m : number
 >m + this.n : any
 >m : number
@@ -602,11 +602,11 @@ c.explicitC = m => m + this.n;
 >n : any
 
 c.explicitThis = m => m + this.n;
->c.explicitThis = m => m + this.n : (m: number) => any
+>c.explicitThis = m => m + this.n : (this: C, m: number) => any
 >c.explicitThis : (this: C, m: number) => number
 >c : C
 >explicitThis : (this: C, m: number) => number
->m => m + this.n : (m: number) => any
+>m => m + this.n : (this: C, m: number) => any
 >m : number
 >m + this.n : any
 >m : number
@@ -615,11 +615,11 @@ c.explicitThis = m => m + this.n;
 >n : any
 
 c.explicitProperty = m => m + this.n;
->c.explicitProperty = m => m + this.n : (m: number) => any
+>c.explicitProperty = m => m + this.n : (this: { n: number; }, m: number) => any
 >c.explicitProperty : (this: { n: number; }, m: number) => number
 >c : C
 >explicitProperty : (this: { n: number; }, m: number) => number
->m => m + this.n : (m: number) => any
+>m => m + this.n : (this: { n: number; }, m: number) => any
 >m : number
 >m + this.n : any
 >m : number
@@ -652,11 +652,11 @@ c.explicitThis = function(this: C, m: number) { return this.n + m };
 
 // this:any compatibility
 c.explicitC = function(m) { return this.n + m };
->c.explicitC = function(m) { return this.n + m } : (m: number) => number
+>c.explicitC = function(m) { return this.n + m } : (this: C, m: number) => number
 >c.explicitC : (this: C, m: number) => number
 >c : C
 >explicitC : (this: C, m: number) => number
->function(m) { return this.n + m } : (m: number) => number
+>function(m) { return this.n + m } : (this: C, m: number) => number
 >m : number
 >this.n + m : number
 >this.n : number
@@ -665,11 +665,11 @@ c.explicitC = function(m) { return this.n + m };
 >m : number
 
 c.explicitProperty = function(m) { return this.n + m };
->c.explicitProperty = function(m) { return this.n + m } : (m: number) => number
+>c.explicitProperty = function(m) { return this.n + m } : (this: { n: number; }, m: number) => number
 >c.explicitProperty : (this: { n: number; }, m: number) => number
 >c : C
 >explicitProperty : (this: { n: number; }, m: number) => number
->function(m) { return this.n + m } : (m: number) => number
+>function(m) { return this.n + m } : (this: { n: number; }, m: number) => number
 >m : number
 >this.n + m : number
 >this.n : number
@@ -678,11 +678,11 @@ c.explicitProperty = function(m) { return this.n + m };
 >m : number
 
 c.explicitThis = function(m) { return this.n + m };
->c.explicitThis = function(m) { return this.n + m } : (m: number) => number
+>c.explicitThis = function(m) { return this.n + m } : (this: C, m: number) => number
 >c.explicitThis : (this: C, m: number) => number
 >c : C
 >explicitThis : (this: C, m: number) => number
->function(m) { return this.n + m } : (m: number) => number
+>function(m) { return this.n + m } : (this: C, m: number) => number
 >m : number
 >this.n + m : number
 >this.n : number
@@ -723,11 +723,11 @@ c.explicitC = function(this: B, m: number) { return this.n + m };
 
 // this:void compatibility
 c.explicitVoid = n => n;
->c.explicitVoid = n => n : (n: number) => number
+>c.explicitVoid = n => n : (this: void, n: number) => number
 >c.explicitVoid : (this: void, m: number) => number
 >c : C
 >explicitVoid : (this: void, m: number) => number
->n => n : (n: number) => number
+>n => n : (this: void, n: number) => number
 >n : number
 >n : number
 

tests/baselines/reference/thisTypeInFunctions2.symbols

@@ -61,12 +61,12 @@ extend1({
 >init : Symbol(init, Decl(thisTypeInFunctions2.ts, 20, 9))
 
         this // this: IndexedWithThis because of contextual typing.
->this : Symbol(IndexedWithThis, Decl(thisTypeInFunctions2.ts, 0, 0))
+>this : Symbol(this, Decl(thisTypeInFunctions2.ts, 2, 12))
 
         // this.mine
         this.willDestroy
 >this.willDestroy : Symbol(IndexedWithThis.willDestroy, Decl(thisTypeInFunctions2.ts, 2, 32))
->this : Symbol(IndexedWithThis, Decl(thisTypeInFunctions2.ts, 0, 0))
+>this : Symbol(this, Decl(thisTypeInFunctions2.ts, 2, 12))
 >willDestroy : Symbol(IndexedWithThis.willDestroy, Decl(thisTypeInFunctions2.ts, 2, 32))
 
     },
@@ -77,7 +77,10 @@ extend1({
 >foo : Symbol(foo, Decl(thisTypeInFunctions2.ts, 26, 13))
 
         this.url; // this: any because 'foo' matches the string indexer
+>this : Symbol(this, Decl(thisTypeInFunctions2.ts, 4, 87))
+
         this.willDestroy;
+>this : Symbol(this, Decl(thisTypeInFunctions2.ts, 4, 87))
     }
 });
 extend2({

tests/baselines/reference/thisTypeInFunctions2.types

@@ -58,10 +58,10 @@ declare function simple(arg: SimpleInterface): void;
 extend1({
 >extend1({    init() {        this // this: IndexedWithThis because of contextual typing.        // this.mine        this.willDestroy    },    mine: 12,    foo() {        this.url; // this: any because 'foo' matches the string indexer        this.willDestroy;    }}) : void
 >extend1 : (args: IndexedWithThis) => void
->{    init() {        this // this: IndexedWithThis because of contextual typing.        // this.mine        this.willDestroy    },    mine: 12,    foo() {        this.url; // this: any because 'foo' matches the string indexer        this.willDestroy;    }} : { init(): void; mine: number; foo(): void; }
+>{    init() {        this // this: IndexedWithThis because of contextual typing.        // this.mine        this.willDestroy    },    mine: 12,    foo() {        this.url; // this: any because 'foo' matches the string indexer        this.willDestroy;    }} : { init(this: IndexedWithThis): void; mine: number; foo(this: any): void; }
 
     init() {
->init : () => void
+>init : (this: IndexedWithThis) => void
 
         this // this: IndexedWithThis because of contextual typing.
 >this : IndexedWithThis
@@ -78,7 +78,7 @@ extend1({
 >12 : number
 
     foo() {
->foo : () => void
+>foo : (this: any) => void
 
         this.url; // this: any because 'foo' matches the string indexer
 >this.url : any

tests/cases/compiler/instantiateContextuallyTypedGenericThis.ts

@@ -1,7 +1,7 @@
 interface JQuery {
     each<T>(
         collection: T[], callback: (this: T, dit: T) => T
-    ): any;
+    ): T[];
 }
 
 let $: JQuery;