Merge pull request #26473 from Microsoft/doGlobalImplicitThisRight

Fix bad message for captured global 'this'.

Author: DanielRosenwasser

src/compiler/checker.ts

@@ -15497,9 +15497,9 @@ namespace ts {
                 // With noImplicitThis, functions may not reference 'this' if it has type 'any'
                 error(
                     node,
-                    capturedByArrowFunction ?
-                        Diagnostics.this_implicitly_has_type_any_because_it_does_not_have_a_type_annotation :
-                        Diagnostics.The_containing_arrow_function_captures_the_global_value_of_this_which_implicitly_has_type_any);
+                    capturedByArrowFunction && container.kind === SyntaxKind.SourceFile ?
+                        Diagnostics.The_containing_arrow_function_captures_the_global_value_of_this_which_implicitly_has_type_any :
+                        Diagnostics.this_implicitly_has_type_any_because_it_does_not_have_a_type_annotation);
             }
             return type || anyType;
         }

tests/baselines/reference/noImplicitThisFunctions.errors.txt

@@ -1,8 +1,11 @@
-tests/cases/compiler/noImplicitThisFunctions.ts(13,12): error TS7041: The containing arrow function captures the global value of 'this' which implicitly has type 'any'.
-tests/cases/compiler/noImplicitThisFunctions.ts(17,38): error TS2683: 'this' implicitly has type 'any' because it does not have a type annotation.
+tests/cases/compiler/noImplicitThisFunctions.ts(13,12): error TS2683: 'this' implicitly has type 'any' because it does not have a type annotation.
+tests/cases/compiler/noImplicitThisFunctions.ts(17,38): error TS7041: The containing arrow function captures the global value of 'this' which implicitly has type 'any'.
+tests/cases/compiler/noImplicitThisFunctions.ts(18,22): error TS7041: The containing arrow function captures the global value of 'this' which implicitly has type 'any'.
+tests/cases/compiler/noImplicitThisFunctions.ts(20,36): error TS2683: 'this' implicitly has type 'any' because it does not have a type annotation.
+tests/cases/compiler/noImplicitThisFunctions.ts(21,50): error TS2683: 'this' implicitly has type 'any' because it does not have a type annotation.
 
 
-==== tests/cases/compiler/noImplicitThisFunctions.ts (2 errors) ====
+==== tests/cases/compiler/noImplicitThisFunctions.ts (5 errors) ====
     function f1(x) {
         // implicit any is still allowed
         return x + 1;
@@ -17,11 +20,21 @@ tests/cases/compiler/noImplicitThisFunctions.ts(17,38): error TS2683: 'this' imp
         // error: this is implicitly any
         return this.a + z;
                ~~~~
-!!! error TS7041: The containing arrow function captures the global value of 'this' which implicitly has type 'any'.
+!!! error TS2683: 'this' implicitly has type 'any' because it does not have a type annotation.
     }
 
     // error: `this` is `window`, but is still of type `any`
     let f4: (b: number) => number = b => this.c + b;
                                          ~~~~
+!!! error TS7041: The containing arrow function captures the global value of 'this' which implicitly has type 'any'.
+    let f5 = () => () => this;
+                         ~~~~
+!!! error TS7041: The containing arrow function captures the global value of 'this' which implicitly has type 'any'.
+    
+    let f6 = function() { return () => this; };
+                                       ~~~~
+!!! error TS2683: 'this' implicitly has type 'any' because it does not have a type annotation.
+    let f7 = function() { return function() { return this } };
+                                                     ~~~~
 !!! error TS2683: 'this' implicitly has type 'any' because it does not have a type annotation.
 

tests/baselines/reference/noImplicitThisFunctions.js

@@ -16,6 +16,10 @@ function f3(z: number): number {
 
 // error: `this` is `window`, but is still of type `any`
 let f4: (b: number) => number = b => this.c + b;
+let f5 = () => () => this;
+
+let f6 = function() { return () => this; };
+let f7 = function() { return function() { return this } };
 
 
 //// [noImplicitThisFunctions.js]
@@ -34,3 +38,9 @@ function f3(z) {
 }
 // error: `this` is `window`, but is still of type `any`
 var f4 = function (b) { return _this.c + b; };
+var f5 = function () { return function () { return _this; }; };
+var f6 = function () {
+    var _this = this;
+    return function () { return _this; };
+};
+var f7 = function () { return function () { return this; }; };

tests/baselines/reference/noImplicitThisFunctions.symbols

@@ -33,3 +33,12 @@ let f4: (b: number) => number = b => this.c + b;
 >b : Symbol(b, Decl(noImplicitThisFunctions.ts, 16, 31))
 >b : Symbol(b, Decl(noImplicitThisFunctions.ts, 16, 31))
 
+let f5 = () => () => this;
+>f5 : Symbol(f5, Decl(noImplicitThisFunctions.ts, 17, 3))
+
+let f6 = function() { return () => this; };
+>f6 : Symbol(f6, Decl(noImplicitThisFunctions.ts, 19, 3))
+
+let f7 = function() { return function() { return this } };
+>f7 : Symbol(f7, Decl(noImplicitThisFunctions.ts, 20, 3))
+

tests/baselines/reference/noImplicitThisFunctions.types

@@ -46,3 +46,21 @@ let f4: (b: number) => number = b => this.c + b;
 >c : any
 >b : number
 
+let f5 = () => () => this;
+>f5 : () => () => any
+>() => () => this : () => () => any
+>() => this : () => any
+>this : any
+
+let f6 = function() { return () => this; };
+>f6 : () => () => any
+>function() { return () => this; } : () => () => any
+>() => this : () => any
+>this : any
+
+let f7 = function() { return function() { return this } };
+>f7 : () => () => any
+>function() { return function() { return this } } : () => () => any
+>function() { return this } : () => any
+>this : any
+

tests/baselines/reference/thisBinding2.errors.txt

@@ -1,4 +1,4 @@
-tests/cases/compiler/thisBinding2.ts(10,11): error TS7041: The containing arrow function captures the global value of 'this' which implicitly has type 'any'.
+tests/cases/compiler/thisBinding2.ts(10,11): error TS2683: 'this' implicitly has type 'any' because it does not have a type annotation.
 
 
 ==== tests/cases/compiler/thisBinding2.ts (1 errors) ====
@@ -13,7 +13,7 @@ tests/cases/compiler/thisBinding2.ts(10,11): error TS7041: The containing arrow
        var x = 1;
        return this.x;
               ~~~~
-!!! error TS7041: The containing arrow function captures the global value of 'this' which implicitly has type 'any'.
+!!! error TS2683: 'this' implicitly has type 'any' because it does not have a type annotation.
       }();
         }  
     }

tests/cases/compiler/noImplicitThisFunctions.ts

@@ -17,3 +17,7 @@ function f3(z: number): number {
 
 // error: `this` is `window`, but is still of type `any`
 let f4: (b: number) => number = b => this.c + b;
+let f5 = () => () => this;
+
+let f6 = function() { return () => this; };
+let f7 = function() { return function() { return this } };