Add globalThis

src/compiler/binder.ts

@@ -2462,8 +2462,13 @@ namespace ts {
                     declareSymbol(symbolTable, containingClass.symbol, node, SymbolFlags.Property, SymbolFlags.None, /*isReplaceableByMethod*/ true);
                     break;
                 case SyntaxKind.SourceFile:
-                    // this.foo assignment in a source file
-                    // Do not bind. It would be nice to support this someday though.
+                    // this.property = assignment in a source file -- declare symbol in exports for a module, in locals for a script
+                    if ((thisContainer as SourceFile).commonJsModuleIndicator) {
+                        declareSymbol(thisContainer.symbol.exports!, thisContainer.symbol, node, SymbolFlags.Property | SymbolFlags.ExportValue, SymbolFlags.None);
+                    }
+                    else {
+                        declareSymbolAndAddToSymbolTable(node, SymbolFlags.FunctionScopedVariable, SymbolFlags.FunctionScopedVariableExcludes);
+                    }
                     break;
 
                 default:

src/compiler/checker.ts

@@ -87,8 +87,14 @@ namespace ts {
         const emitResolver = createResolver();
         const nodeBuilder = createNodeBuilder();
 
+        const globals = createSymbolTable();
         const undefinedSymbol = createSymbol(SymbolFlags.Property, "undefined" as __String);
         undefinedSymbol.declarations = [];
+
+        const globalThisSymbol = createSymbol(SymbolFlags.ValueModule | SymbolFlags.NamespaceModule, "globalThis" as __String);
+        globalThisSymbol.exports = globals;
+        globalThisSymbol.valueDeclaration = createNode(SyntaxKind.Identifier) as Identifier;
+        (globalThisSymbol.valueDeclaration as Identifier).escapedText = "globalThis" as __String;
         const argumentsSymbol = createSymbol(SymbolFlags.Property, "arguments" as __String);
         const requireSymbol = createSymbol(SymbolFlags.Property, "require" as __String);
 
@@ -458,7 +464,6 @@ namespace ts {
 
         const enumNumberIndexInfo = createIndexInfo(stringType, /*isReadonly*/ true);
 
-        const globals = createSymbolTable();
         interface DuplicateInfoForSymbol {
             readonly firstFileLocations: Node[];
             readonly secondFileLocations: Node[];
@@ -721,6 +726,7 @@ namespace ts {
 
         const builtinGlobals = createSymbolTable();
         builtinGlobals.set(undefinedSymbol.escapedName, undefinedSymbol);
+        builtinGlobals.set(globalThisSymbol.escapedName, globalThisSymbol);
 
         const isNotOverloadAndNotAccessor = and(isNotOverload, isNotAccessor);
 
@@ -9618,7 +9624,7 @@ namespace ts {
         }
 
         function getLiteralTypeFromProperties(type: Type, include: TypeFlags) {
-            return getUnionType(map(getPropertiesOfType(type), t => getLiteralTypeFromProperty(t, include)));
+            return getUnionType(map(getPropertiesOfType(type), p => getLiteralTypeFromProperty(p, include)));
         }
 
         function getNonEnumNumberIndexInfo(type: Type) {
@@ -16695,17 +16701,19 @@ namespace ts {
             }
 
             const type = tryGetThisTypeAt(node, container);
-            if (!type && noImplicitThis) {
-                // With noImplicitThis, functions may not reference 'this' if it has type 'any'
-                const diag = error(
-                    node,
-                    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);
-                if (!isSourceFile(container)) {
-                    const outsideThis = tryGetThisTypeAt(container);
-                    if (outsideThis) {
-                        addRelatedInfo(diag, createDiagnosticForNode(container, Diagnostics.An_outer_value_of_this_is_shadowed_by_this_container));
+            const globalThisType = getTypeOfSymbol(globalThisSymbol);
+            if (noImplicitThis) {
+                if (type === globalThisType && capturedByArrowFunction) {
+                    error(node, Diagnostics.The_containing_arrow_function_captures_the_global_value_of_this);
+                }
+                else if (!type) {
+                    // With noImplicitThis, functions may not reference 'this' if it has type 'any'
+                    const diag = error(node, Diagnostics.this_implicitly_has_type_any_because_it_does_not_have_a_type_annotation);
+                    if (!isSourceFile(container)) {
+                        const outsideThis = tryGetThisTypeAt(container);
+                        if (outsideThis && outsideThis !== globalThisType) {
+                            addRelatedInfo(diag, createDiagnosticForNode(container, Diagnostics.An_outer_value_of_this_is_shadowed_by_this_container));
+                        }
                     }
                 }
             }
@@ -16759,6 +16767,16 @@ namespace ts {
                     return getFlowTypeOfReference(node, type);
                 }
             }
+            if (isSourceFile(container)) {
+                // look up in the source file's locals or exports
+                if (container.commonJsModuleIndicator) {
+                    const fileSymbol = getSymbolOfNode(container);
+                    return fileSymbol && getTypeOfSymbol(fileSymbol);
+                }
+                else {
+                    return getTypeOfSymbol(globalThisSymbol);
+                }
+            }
         }
 
         function getClassNameFromPrototypeMethod(container: Node) {
@@ -19017,6 +19035,12 @@ namespace ts {
                     if (isJSLiteralType(leftType)) {
                         return anyType;
                     }
+                    if (leftType.symbol === globalThisSymbol) {
+                        if (noImplicitAny) {
+                            error(right, Diagnostics.Element_implicitly_has_an_any_type_because_type_0_has_no_index_signature, typeToString(leftType));
+                        }
+                        return anyType;
+                    }
                     if (right.escapedText && !checkAndReportErrorForExtendingInterface(node)) {
                         reportNonexistentProperty(right, leftType.flags & TypeFlags.TypeParameter && (leftType as TypeParameter).isThisType ? apparentType : leftType);
                     }

src/compiler/diagnosticMessages.json

@@ -4097,7 +4097,7 @@
         "category": "Error",
         "code": 7040
     },
-    "The containing arrow function captures the global value of 'this' which implicitly has type 'any'.": {
+    "The containing arrow function captures the global value of 'this'.": {
         "category": "Error",
         "code": 7041
     },

src/lib/esnext.globalthis.d.ts

@@ -0,0 +1 @@
+declare var globalThis: typeof globalThis;

src/services/completions.ts

@@ -1029,7 +1029,7 @@ namespace ts.Completions {
             // Need to insert 'this.' before properties of `this` type, so only do that if `includeInsertTextCompletions`
             if (preferences.includeCompletionsWithInsertText && scopeNode.kind !== SyntaxKind.SourceFile) {
                 const thisType = typeChecker.tryGetThisTypeAt(scopeNode);
-                if (thisType) {
+                if (thisType && thisType.symbol.name !== "globalThis") {
                     for (const symbol of getPropertiesForCompletion(thisType, typeChecker)) {
                         symbolToOriginInfoMap[getSymbolId(symbol)] = { kind: SymbolOriginInfoKind.ThisType };
                         symbols.push(symbol);

tests/baselines/reference/assignmentLHSIsValue.symbols

@@ -27,6 +27,7 @@ function foo() { this = value; }
 >value : Symbol(value, Decl(assignmentLHSIsValue.ts, 1, 3))
 
 this = value;
+>this : Symbol(globalThis)
 >value : Symbol(value, Decl(assignmentLHSIsValue.ts, 1, 3))
 
 // identifiers: module, class, enum, function
@@ -116,6 +117,7 @@ foo() = value;
 
 // parentheses, the containted expression is value
 (this) = value;
+>this : Symbol(globalThis)
 >value : Symbol(value, Decl(assignmentLHSIsValue.ts, 1, 3))
 
 (M) = value;

tests/baselines/reference/assignmentLHSIsValue.types

@@ -33,7 +33,7 @@ function foo() { this = value; }
 
 this = value;
 >this = value : any
->this : any
+>this : typeof globalThis
 >value : any
 
 // identifiers: module, class, enum, function
@@ -159,8 +159,8 @@ foo() = value;
 // parentheses, the containted expression is value
 (this) = value;
 >(this) = value : any
->(this) : any
->this : any
+>(this) : typeof globalThis
+>this : typeof globalThis
 >value : any
 
 (M) = value;

tests/baselines/reference/castExpressionParentheses.symbols

@@ -21,7 +21,11 @@ declare var a;
 (<any>null); 
 // names and dotted names
 (<any>this); 
+>this : Symbol(globalThis)
+
 (<any>this.x); 
+>this : Symbol(globalThis)
+
 (<any>(<any>a).x);
 >a : Symbol(a, Decl(castExpressionParentheses.ts, 0, 11))
 

tests/baselines/reference/castExpressionParentheses.types

@@ -77,13 +77,13 @@ declare var a;
 (<any>this); 
 >(<any>this) : any
 ><any>this : any
->this : any
+>this : typeof globalThis
 
 (<any>this.x); 
 >(<any>this.x) : any
 ><any>this.x : any
 >this.x : any
->this : any
+>this : typeof globalThis
 >x : any
 
 (<any>(<any>a).x);

tests/baselines/reference/collisionThisExpressionAndAliasInGlobal.symbols

@@ -7,6 +7,7 @@ module a {
 }
 var f = () => this;
 >f : Symbol(f, Decl(collisionThisExpressionAndAliasInGlobal.ts, 3, 3))
+>this : Symbol(globalThis)
 
 import _this = a; // Error
 >_this : Symbol(_this, Decl(collisionThisExpressionAndAliasInGlobal.ts, 3, 19))

tests/baselines/reference/collisionThisExpressionAndAliasInGlobal.types

@@ -7,9 +7,9 @@ module a {
 >10 : 10
 }
 var f = () => this;
->f : () => any
->() => this : () => any
->this : any
+>f : () => typeof globalThis
+>() => this : () => typeof globalThis
+>this : typeof globalThis
 
 import _this = a; // Error
 >_this : typeof a

tests/baselines/reference/collisionThisExpressionAndAmbientClassInGlobal.symbols

@@ -4,6 +4,7 @@ declare class _this { // no error - as no code generation
 }
 var f = () => this;
 >f : Symbol(f, Decl(collisionThisExpressionAndAmbientClassInGlobal.ts, 2, 3))
+>this : Symbol(globalThis)
 
 var a = new _this(); // Error
 >a : Symbol(a, Decl(collisionThisExpressionAndAmbientClassInGlobal.ts, 3, 3))

tests/baselines/reference/collisionThisExpressionAndAmbientClassInGlobal.types

@@ -3,9 +3,9 @@ declare class _this { // no error - as no code generation
 >_this : _this
 }
 var f = () => this;
->f : () => any
->() => this : () => any
->this : any
+>f : () => typeof globalThis
+>() => this : () => typeof globalThis
+>this : typeof globalThis
 
 var a = new _this(); // Error
 >a : _this

tests/baselines/reference/collisionThisExpressionAndAmbientVarInGlobal.symbols

@@ -4,6 +4,7 @@ declare var _this: number; // no error as no code gen
 
 var f = () => this;
 >f : Symbol(f, Decl(collisionThisExpressionAndAmbientVarInGlobal.ts, 1, 3))
+>this : Symbol(globalThis)
 
 _this = 10; // Error
 >_this : Symbol(_this, Decl(collisionThisExpressionAndAmbientVarInGlobal.ts, 0, 11))

tests/baselines/reference/collisionThisExpressionAndAmbientVarInGlobal.types

@@ -3,9 +3,9 @@ declare var _this: number; // no error as no code gen
 >_this : number
 
 var f = () => this;
->f : () => any
->() => this : () => any
->this : any
+>f : () => typeof globalThis
+>() => this : () => typeof globalThis
+>this : typeof globalThis
 
 _this = 10; // Error
 >_this = 10 : 10

tests/baselines/reference/collisionThisExpressionAndClassInGlobal.symbols

@@ -4,4 +4,5 @@ class _this {
 }
 var f = () => this;
 >f : Symbol(f, Decl(collisionThisExpressionAndClassInGlobal.ts, 2, 3))
+>this : Symbol(globalThis)
 

tests/baselines/reference/collisionThisExpressionAndClassInGlobal.types

@@ -3,7 +3,7 @@ class _this {
 >_this : _this
 }
 var f = () => this;
->f : () => any
->() => this : () => any
->this : any
+>f : () => typeof globalThis
+>() => this : () => typeof globalThis
+>this : typeof globalThis
 

tests/baselines/reference/collisionThisExpressionAndEnumInGlobal.symbols

@@ -10,4 +10,5 @@ enum _this { // Error
 }
 var f = () => this;
 >f : Symbol(f, Decl(collisionThisExpressionAndEnumInGlobal.ts, 4, 3))
+>this : Symbol(globalThis)
 

tests/baselines/reference/collisionThisExpressionAndEnumInGlobal.types

@@ -9,7 +9,7 @@ enum _this { // Error
 >_thisVal2 : _this._thisVal2
 }
 var f = () => this;
->f : () => any
->() => this : () => any
->this : any
+>f : () => typeof globalThis
+>() => this : () => typeof globalThis
+>this : typeof globalThis
 

tests/baselines/reference/collisionThisExpressionAndFunctionInGlobal.symbols

@@ -6,4 +6,5 @@ function _this() { //Error
 }
 var f = () => this;
 >f : Symbol(f, Decl(collisionThisExpressionAndFunctionInGlobal.ts, 3, 3))
+>this : Symbol(globalThis)
 

tests/baselines/reference/collisionThisExpressionAndFunctionInGlobal.types

@@ -6,7 +6,7 @@ function _this() { //Error
 >10 : 10
 }
 var f = () => this;
->f : () => any
->() => this : () => any
->this : any
+>f : () => typeof globalThis
+>() => this : () => typeof globalThis
+>this : typeof globalThis
 

tests/baselines/reference/collisionThisExpressionAndLocalVarInLambda.symbols

@@ -15,6 +15,7 @@ var x = {
 
         return callback(this);
 >callback : Symbol(callback, Decl(collisionThisExpressionAndLocalVarInLambda.ts, 3, 14))
+>this : Symbol(globalThis)
     }
 }
 alert(x.doStuff(x => alert(x)));

tests/baselines/reference/collisionThisExpressionAndLocalVarInLambda.types

@@ -20,7 +20,7 @@ var x = {
         return callback(this);
 >callback(this) : any
 >callback : any
->this : any
+>this : typeof globalThis
     }
 }
 alert(x.doStuff(x => alert(x)));

tests/baselines/reference/collisionThisExpressionAndModuleInGlobal.symbols

@@ -8,4 +8,5 @@ module _this { //Error
 }
 var f = () => this;
 >f : Symbol(f, Decl(collisionThisExpressionAndModuleInGlobal.ts, 4, 3))
+>this : Symbol(globalThis)
 

tests/baselines/reference/collisionThisExpressionAndModuleInGlobal.types

@@ -7,7 +7,7 @@ module _this { //Error
     }
 }
 var f = () => this;
->f : () => any
->() => this : () => any
->this : any
+>f : () => typeof globalThis
+>() => this : () => typeof globalThis
+>this : typeof globalThis
 

tests/baselines/reference/collisionThisExpressionAndVarInGlobal.symbols

@@ -4,4 +4,5 @@ var _this = 1;
 
 var f = () => this;
 >f : Symbol(f, Decl(collisionThisExpressionAndVarInGlobal.ts, 1, 3))
+>this : Symbol(globalThis)
 

tests/baselines/reference/collisionThisExpressionAndVarInGlobal.types

@@ -4,7 +4,7 @@ var _this = 1;
 >1 : 1
 
 var f = () => this;
->f : () => any
->() => this : () => any
->this : any
+>f : () => typeof globalThis
+>() => this : () => typeof globalThis
+>this : typeof globalThis
 

tests/baselines/reference/commentsInterface.symbols

@@ -187,19 +187,25 @@ i3_i = {
 
     l: this.f,
 >l : Symbol(l, Decl(commentsInterface.ts, 56, 56))
+>this : Symbol(globalThis)
 
     /** own x*/
     x: this.f(10),
 >x : Symbol(x, Decl(commentsInterface.ts, 57, 14))
+>this : Symbol(globalThis)
 
     nc_x: this.l(this.x),
 >nc_x : Symbol(nc_x, Decl(commentsInterface.ts, 59, 18))
+>this : Symbol(globalThis)
+>this : Symbol(globalThis)
 
     nc_f: this.f,
 >nc_f : Symbol(nc_f, Decl(commentsInterface.ts, 60, 25))
+>this : Symbol(globalThis)
 
     nc_l: this.l
 >nc_l : Symbol(nc_l, Decl(commentsInterface.ts, 61, 17))
+>this : Symbol(globalThis)
 
 };
 i3_i.f(10);