Merge pull request #2701 from Microsoft/superAnnoyingEmitInEs6Classes

Don't emit '_this' when encountering 'super' in ES6 emit

Author: DanielRosenwasser

src/compiler/checker.ts

@@ -5582,7 +5582,7 @@ module ts {
                     needToCaptureLexicalThis = false;
                     while (container && container.kind === SyntaxKind.ArrowFunction) {
                         container = getSuperContainer(container, /*includeFunctions*/ true);
-                        needToCaptureLexicalThis = true;
+                        needToCaptureLexicalThis = languageVersion < ScriptTarget.ES6;
                     }
 
                     // topmost container must be something that is directly nested in the class declaration

tests/baselines/reference/computedPropertyNames31_ES6.js

@@ -23,7 +23,6 @@ class Base {
 }
 class C extends Base {
     foo() {
-        var _this = this;
         (() => {
             var obj = {
                 [super.bar()]() { } // needs capture

tests/baselines/reference/emitClassDeclarationWithSuperMethodCall01.js

@@ -0,0 +1,23 @@
+//// [emitClassDeclarationWithSuperMethodCall01.ts]
+
+class Parent {
+    foo() {
+    }
+}
+
+class Foo extends Parent {
+    foo() {
+        var x = () => super.foo();
+    }
+}
+
+//// [emitClassDeclarationWithSuperMethodCall01.js]
+class Parent {
+    foo() {
+    }
+}
+class Foo extends Parent {
+    foo() {
+        var x = () => super.foo();
+    }
+}

tests/baselines/reference/emitClassDeclarationWithSuperMethodCall01.types

@@ -0,0 +1,26 @@
+=== tests/cases/conformance/es6/classDeclaration/emitClassDeclarationWithSuperMethodCall01.ts ===
+
+class Parent {
+>Parent : Parent
+
+    foo() {
+>foo : () => void
+    }
+}
+
+class Foo extends Parent {
+>Foo : Foo
+>Parent : Parent
+
+    foo() {
+>foo : () => void
+
+        var x = () => super.foo();
+>x : () => void
+>() => super.foo() : () => void
+>super.foo() : void
+>super.foo : () => void
+>super : Parent
+>foo : () => void
+    }
+}

tests/cases/conformance/decorators/class/method/decoratorOnClassMethod11.ts

@@ -1,9 +1,9 @@
-// @target: ES5
-module M {
-    class C {
-        decorator(target: Object, key: string): void { }
-
-        @this.decorator
-        method() { }
-    }
+// @target: ES5
+module M {
+    class C {
+        decorator(target: Object, key: string): void { }
+
+        @this.decorator
+        method() { }
+    }
 }

tests/cases/conformance/es6/classDeclaration/emitClassDeclarationWithSuperMethodCall01.ts

@@ -0,0 +1,12 @@
+//@target: es6
+
+class Parent {
+    foo() {
+    }
+}
+
+class Foo extends Parent {
+    foo() {
+        var x = () => super.foo();
+    }
+}