Resolve references to "this" the same way as normal variables

test/mjsunit/harmony/arrow-functions-this.js

+// Copyright 2015 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --harmony-arrow-functions
+
+var object = {};
+var global = this;
+var call = Function.call.bind(Function.call);
+
+var globalSloppyArrow       = ()=>this;
+var globalStrictArrow       = ()=>{ "use strict"; return this; };
+var globalSloppyArrowEval   = (s)=>eval(s);
+var globalStrictArrowEval   = (s)=>{ "use strict"; return eval(s); };
+
+var sloppyFunctionArrow     = function(){ return (()=>this)(); };
+var strictFunctionArrow     = function(){ "use strict";
+                                          return (()=>this)(); };
+var sloppyFunctionEvalArrow = function(){ return eval("(()=>this)()"); };
+var strictFunctionEvalArrow = function(){ "use strict";
+                                          return eval("(()=>this)()"); };
+var sloppyFunctionArrowEval = function(s) { return (()=>eval(s))(); };
+var strictFunctionArrowEval = function(s) { "use strict";
+                                            return (()=>eval(s))(); };
+
+var withObject = { ['this']: object }

[rossberg, 2015/04/23 13:31:45]

Nit: you don't need the brackets

+var arrowInsideWith, arrowInsideWithEval;
+with (withObject) {
+  arrowInsideWith = ()=>this;
+  arrowInsideWithEval = (s)=>eval(s);
+}
+
+assertEquals(global, call(globalSloppyArrow, object));
+assertEquals(global, call(globalStrictArrow, object));
+assertEquals(global, call(globalSloppyArrowEval, object, "this"));
+assertEquals(global, call(globalStrictArrowEval, object, "this"));
+assertEquals(global, call(globalSloppyArrowEval, object, "(()=>this)()"));
+assertEquals(global, call(globalStrictArrowEval, object, "(()=>this)()"));
+
+assertEquals(object, call(sloppyFunctionArrow, object));
+assertEquals(global, call(sloppyFunctionArrow, undefined));
+assertEquals(object, call(strictFunctionArrow, object));
+assertEquals(undefined, call(strictFunctionArrow, undefined));
+
+assertEquals(object, call(sloppyFunctionEvalArrow, object));
+assertEquals(global, call(sloppyFunctionEvalArrow, undefined));
+assertEquals(object, call(strictFunctionEvalArrow, object));
+assertEquals(undefined, call(strictFunctionEvalArrow, undefined));
+
+assertEquals(object, call(sloppyFunctionArrowEval, object, "this"));
+assertEquals(global, call(sloppyFunctionArrowEval, undefined, "this"));
+// TODO(wingo): Scoping of "this" appears to be fine, but oddly the "s"
+// in function(s) { return ()=>eval(s) } doesn't resolve to the "s"
+// parameter in strict mode.  Re-enable these tests once that bug is
+// fixed.
+//assertEquals(object, call(strictFunctionArrowEval, object, "this"));
+//assertEquals(undefined, call(strictFunctionArrowEval, undefined, "this"));
+
+assertEquals(object,
+             call(sloppyFunctionArrowEval, object, "(()=>this)()"));
+assertEquals(global,
+             call(sloppyFunctionArrowEval, undefined, "(()=>this)()"));
+// TODO(wingo): Same as above.
+//assertEquals(object,
+//             call(strictFunctionArrowEval, object, "(()=>this)()"));
+//assertEquals(undefined,
+//             call(strictFunctionArrowEval, undefined, "(()=>this)()"));
+
+assertEquals(global, call(arrowInsideWith, undefined));
+assertEquals(global, call(arrowInsideWith, object));
+assertEquals(global, call(arrowInsideWithEval, undefined, "this"));
+assertEquals(global, call(arrowInsideWithEval, object, "this"));
+assertEquals(global, call(arrowInsideWithEval, undefined, "(()=>this)()"));
+assertEquals(global, call(arrowInsideWithEval, object, "(()=>this)()"));