Merge pull request #2718 from Microsoft/fixEmitDecorate

Fix for __decorate emit on undecorated file following a decorated file

src/compiler/checker.ts

@@ -10848,6 +10848,8 @@ module ts {
                 checkGrammarSourceFile(node);
 
                 emitExtends = false;
+                emitDecorate = false;
+                emitParam = false;
                 potentialThisCollisions.length = 0;
 
                 forEach(node.statements, checkSourceElement);

tests/baselines/reference/decoratedClassFromExternalModule.js

@@ -0,0 +1,28 @@
+//// [tests/cases/conformance/decorators/class/decoratedClassFromExternalModule.ts] ////
+
+//// [decorated.ts]
+function decorate() { }
+
+@decorate
+export default class Decorated { }
+
+//// [undecorated.ts]
+import Decorated from 'decorated';
+
+//// [decorated.js]
+var __decorate = this.__decorate || (typeof Reflect === "object" && Reflect.decorate) || function (decorators, target, key, desc) {
+    switch (arguments.length) {
+        case 2: return decorators.reduceRight(function(o, d) { return (d && d(o)) || o; }, target);
+        case 3: return decorators.reduceRight(function(o, d) { return (d && d(target, key)), void 0; }, void 0);
+        case 4: return decorators.reduceRight(function(o, d) { return (d && d(target, key, o)) || o; }, desc);
+    }
+};
+function decorate() { }
+let Decorated = class {
+};
+Object.defineProperty(Decorated, "name", { value: "Decorated", configurable: true });
+Decorated = __decorate([
+    decorate
+], Decorated);
+export default Decorated;
+//// [undecorated.js]

tests/baselines/reference/decoratedClassFromExternalModule.types

@@ -0,0 +1,14 @@
+=== tests/cases/conformance/decorators/class/decorated.ts ===
+function decorate() { }
+>decorate : () => void
+
+@decorate
+>decorate : () => void
+
+export default class Decorated { }
+>Decorated : Decorated
+
+=== tests/cases/conformance/decorators/class/undecorated.ts ===
+import Decorated from 'decorated';
+>Decorated : typeof Decorated
+

tests/cases/conformance/decorators/class/decoratedClassFromExternalModule.ts

@@ -0,0 +1,9 @@
+// @target: es6
+// @Filename: decorated.ts
+function decorate() { }
+
+@decorate
+export default class Decorated { }
+
+// @Filename: undecorated.ts
+import Decorated from 'decorated';