Fix #2929: relax the check for export= in ES6 if it is resulting from an ambient declaration

src/compiler/checker.ts

@@ -10689,7 +10689,7 @@ module ts {
             }
             checkExternalModuleExports(container);
 
-            if (node.isExportEquals) {
+            if (node.isExportEquals && !isInAmbientContext(node)) {
                 if (languageVersion >= ScriptTarget.ES6) {
                     // export assignment is deprecated in es6 or above
                     grammarErrorOnNode(node, Diagnostics.Export_assignment_cannot_be_used_when_targeting_ECMAScript_6_or_higher_Consider_using_export_default_instead);

tests/baselines/reference/es6ExportAssignment2.errors.txt

@@ -0,0 +1,13 @@
+tests/cases/compiler/a.ts(3,1): error TS1203: Export assignment cannot be used when targeting ECMAScript 6 or higher. Consider using 'export default' instead.
+
+
+==== tests/cases/compiler/a.ts (1 errors) ====
+    
+    var a = 10;
+    export = a;  // Error: export = not allowed in ES6
+    ~~~~~~~~~~~
+!!! error TS1203: Export assignment cannot be used when targeting ECMAScript 6 or higher. Consider using 'export default' instead.
+    
+==== tests/cases/compiler/b.ts (0 errors) ====
+    import * as a from "a";
+    

tests/baselines/reference/es6ExportAssignment2.js

@@ -0,0 +1,14 @@
+//// [tests/cases/compiler/es6ExportAssignment2.ts] ////
+
+//// [a.ts]
+
+var a = 10;
+export = a;  // Error: export = not allowed in ES6
+
+//// [b.ts]
+import * as a from "a";
+
+
+//// [a.js]
+var a = 10;
+//// [b.js]

tests/baselines/reference/es6ExportAssignment3.js

@@ -0,0 +1,12 @@
+//// [tests/cases/compiler/es6ExportAssignment3.ts] ////
+
+//// [a.d.ts]
+
+declare var a: number;
+export = a;  // OK, in ambient context
+
+//// [b.ts]
+import * as a from "a";
+
+
+//// [b.js]

tests/baselines/reference/es6ExportAssignment3.symbols

@@ -0,0 +1,12 @@
+=== tests/cases/compiler/a.d.ts ===
+
+declare var a: number;
+>a : Symbol(a, Decl(a.d.ts, 1, 11))
+
+export = a;  // OK, in ambient context
+>a : Symbol(a, Decl(a.d.ts, 1, 11))
+
+=== tests/cases/compiler/b.ts ===
+import * as a from "a";
+>a : Symbol(a, Decl(b.ts, 0, 6))
+

tests/baselines/reference/es6ExportAssignment3.types

@@ -0,0 +1,12 @@
+=== tests/cases/compiler/a.d.ts ===
+
+declare var a: number;
+>a : number
+
+export = a;  // OK, in ambient context
+>a : number
+
+=== tests/cases/compiler/b.ts ===
+import * as a from "a";
+>a : number
+

tests/baselines/reference/es6ExportAssignment4.js

@@ -0,0 +1,14 @@
+//// [tests/cases/compiler/es6ExportAssignment4.ts] ////
+
+//// [modules.d.ts]
+
+declare module "a" {
+    var a: number;
+    export = a;  // OK, in ambient context
+}
+
+//// [b.ts]
+import * as a from "a";
+
+
+//// [b.js]

tests/baselines/reference/es6ExportAssignment4.symbols

@@ -0,0 +1,14 @@
+=== tests/cases/compiler/modules.d.ts ===
+
+declare module "a" {
+    var a: number;
+>a : Symbol(a, Decl(modules.d.ts, 2, 7))
+
+    export = a;  // OK, in ambient context
+>a : Symbol(a, Decl(modules.d.ts, 2, 7))
+}
+
+=== tests/cases/compiler/b.ts ===
+import * as a from "a";
+>a : Symbol(a, Decl(b.ts, 0, 6))
+

tests/baselines/reference/es6ExportAssignment4.types

@@ -0,0 +1,14 @@
+=== tests/cases/compiler/modules.d.ts ===
+
+declare module "a" {
+    var a: number;
+>a : number
+
+    export = a;  // OK, in ambient context
+>a : number
+}
+
+=== tests/cases/compiler/b.ts ===
+import * as a from "a";
+>a : number
+

tests/baselines/reference/systemExportAssignment.js

@@ -0,0 +1,19 @@
+//// [tests/cases/compiler/systemExportAssignment.ts] ////
+
+//// [a.d.ts]
+
+declare var a: number;
+export = a;  // OK, in ambient context
+
+//// [b.ts]
+import * as a from "a";
+
+
+//// [b.js]
+System.register([], function(exports_1) {
+    return {
+        setters:[],
+        execute: function() {
+        }
+    }
+});

tests/baselines/reference/systemExportAssignment.symbols

@@ -0,0 +1,12 @@
+=== tests/cases/compiler/a.d.ts ===
+
+declare var a: number;
+>a : Symbol(a, Decl(a.d.ts, 1, 11))
+
+export = a;  // OK, in ambient context
+>a : Symbol(a, Decl(a.d.ts, 1, 11))
+
+=== tests/cases/compiler/b.ts ===
+import * as a from "a";
+>a : Symbol(a, Decl(b.ts, 0, 6))
+

tests/baselines/reference/systemExportAssignment.types

@@ -0,0 +1,12 @@
+=== tests/cases/compiler/a.d.ts ===
+
+declare var a: number;
+>a : number
+
+export = a;  // OK, in ambient context
+>a : number
+
+=== tests/cases/compiler/b.ts ===
+import * as a from "a";
+>a : number
+

tests/baselines/reference/systemExportAssignment2.errors.txt

@@ -0,0 +1,13 @@
+tests/cases/compiler/a.ts(3,1): error TS1218: Export assignment is not supported when '--module' flag is 'system'.
+
+
+==== tests/cases/compiler/a.ts (1 errors) ====
+    
+    var a = 10;
+    export = a;  // Error: export = not allowed in ES6
+    ~~~~~~~~~~~
+!!! error TS1218: Export assignment is not supported when '--module' flag is 'system'.
+    
+==== tests/cases/compiler/b.ts (0 errors) ====
+    import * as a from "a";
+    

tests/baselines/reference/systemExportAssignment2.js

@@ -0,0 +1,29 @@
+//// [tests/cases/compiler/systemExportAssignment2.ts] ////
+
+//// [a.ts]
+
+var a = 10;
+export = a;  // Error: export = not allowed in ES6
+
+//// [b.ts]
+import * as a from "a";
+
+
+//// [a.js]
+System.register([], function(exports_1) {
+    var a;
+    return {
+        setters:[],
+        execute: function() {
+            a = 10;
+        }
+    }
+});
+//// [b.js]
+System.register([], function(exports_1) {
+    return {
+        setters:[],
+        execute: function() {
+        }
+    }
+});

tests/baselines/reference/systemExportAssignment3.js

@@ -0,0 +1,21 @@
+//// [tests/cases/compiler/systemExportAssignment3.ts] ////
+
+//// [modules.d.ts]
+
+declare module "a" {
+    var a: number;
+    export = a;  // OK, in ambient context
+}
+
+//// [b.ts]
+import * as a from "a";
+
+
+//// [b.js]
+System.register([], function(exports_1) {
+    return {
+        setters:[],
+        execute: function() {
+        }
+    }
+});

tests/baselines/reference/systemExportAssignment3.symbols

@@ -0,0 +1,14 @@
+=== tests/cases/compiler/modules.d.ts ===
+
+declare module "a" {
+    var a: number;
+>a : Symbol(a, Decl(modules.d.ts, 2, 7))
+
+    export = a;  // OK, in ambient context
+>a : Symbol(a, Decl(modules.d.ts, 2, 7))
+}
+
+=== tests/cases/compiler/b.ts ===
+import * as a from "a";
+>a : Symbol(a, Decl(b.ts, 0, 6))
+

tests/baselines/reference/systemExportAssignment3.types

@@ -0,0 +1,14 @@
+=== tests/cases/compiler/modules.d.ts ===
+
+declare module "a" {
+    var a: number;
+>a : number
+
+    export = a;  // OK, in ambient context
+>a : number
+}
+
+=== tests/cases/compiler/b.ts ===
+import * as a from "a";
+>a : number
+

tests/cases/compiler/es6ExportAssignment2.ts

@@ -0,0 +1,8 @@
+// @target: es6
+
+// @filename: a.ts
+var a = 10;
+export = a;  // Error: export = not allowed in ES6
+
+// @filename: b.ts
+import * as a from "a";

tests/cases/compiler/es6ExportAssignment3.ts

@@ -0,0 +1,8 @@
+// @target: es6
+
+// @filename: a.d.ts
+declare var a: number;
+export = a;  // OK, in ambient context
+
+// @filename: b.ts
+import * as a from "a";

tests/cases/compiler/es6ExportAssignment4.ts

@@ -0,0 +1,10 @@
+// @target: es6
+
+// @filename: modules.d.ts
+declare module "a" {
+    var a: number;
+    export = a;  // OK, in ambient context
+}
+
+// @filename: b.ts
+import * as a from "a";

tests/cases/compiler/systemExportAssignment.ts

@@ -0,0 +1,9 @@
+// @target: es5
+// @module: system
+
+// @filename: a.d.ts
+declare var a: number;
+export = a;  // OK, in ambient context
+
+// @filename: b.ts
+import * as a from "a";

tests/cases/compiler/systemExportAssignment2.ts

@@ -0,0 +1,9 @@
+// @target: es5
+// @module: system
+
+// @filename: a.ts
+var a = 10;
+export = a;  // Error: export = not allowed in ES6
+
+// @filename: b.ts
+import * as a from "a";

tests/cases/compiler/systemExportAssignment3.ts

@@ -0,0 +1,11 @@
+// @target: es5
+// @module: system
+
+// @filename: modules.d.ts
+declare module "a" {
+    var a: number;
+    export = a;  // OK, in ambient context
+}
+
+// @filename: b.ts
+import * as a from "a";