[es6] Implement default parameters

test/mjsunit/harmony/destructuring.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-destructuring
-// Flags: --harmony-arrow-functions --harmony-rest-parameters
+// Flags: --harmony-destructuring --harmony-arrow-functions
+// Flags: --harmony-default-parameters --harmony-rest-parameters
 
 (function TestObjectLiteralPattern() {
   var { x : x, y : y } = { x : 1, y : 2 };
   assertEquals(1, x);
   assertEquals(2, y);
 
   var {z} = { z : 3 };
   assertEquals(3, z);
 
 
@@ skipping 699 matching lines @@
 
   var g2 = ({c, d}, {a, b}) => { return c - d + a - b; };
   assertEquals(7, g2({c : 7, d : 1}, {a : 6, b : 5}));
 
   var g3 = ([{a, b}]) => { return a - b; };
   assertEquals(1, g3([{a : 6, b : 5}]));
 }());
 
 
 (function TestExpressionsInParameters() {
+  function f0(x = eval(0)) { return x }
+  assertEquals(0, f0());
   function f1({a = eval(1)}) { return a }
   assertEquals(1, f1({}));
   function f2([x = eval(2)]) { return x }
   assertEquals(2, f2([]));
   function f3({[eval(7)]: x}) { return x }
   assertEquals(3, f3({7: 3}));
-  // TODO(rossberg, caitp): Add tests for default parameters.
 })();
 
 
 (function TestParameterScoping() {
   var x = 1;
 
   function f1({a = x}) { var x = 2; return a; }
   assertEquals(1, f1({}));
   function f2({a = x}) { function x() {}; return a; }
   assertEquals(1, f2({}));
@@ skipping 69 matching lines @@
   assertEquals(1, f20({a: 1, b: 2}));
   function f21({[eval('y')]: x}) { var y = 'b'; return x; }
   assertEquals(1, f21({a: 1, b: 2}));
   var g20 = ({[y]: x}) => { var y = 'b'; return x; };
   assertEquals(1, g20({a: 1, b: 2}));
   var g21 = ({[eval('y')]: x}) => { var y = 'b'; return x; };
   assertEquals(1, g21({a: 1, b: 2}));
 })();
 
 
-(function TestParameterTDZ() {
+(function TestParameterDestructuringTDZ() {
   function f1({a = x}, x) { return a }
   assertThrows(() => f1({}, 4), ReferenceError);
   assertEquals(4, f1({a: 4}, 5));
   function f2({a = eval("x")}, x) { return a }
   assertThrows(() => f2({}, 4), ReferenceError);
   assertEquals(4, f2({a: 4}, 5));
   function f3({a = eval("x")}, x) { 'use strict'; return a }
   assertThrows(() => f3({}, 4), ReferenceError);
   assertEquals(4, f3({a: 4}, 5));
   function f4({a = eval("'use strict'; x")}, x) { return a }
@@ skipping 103 matching lines @@
   function f4(x, {}) { x = 2; return arguments[0] }
   assertEquals(7, f4(7, {}));
   function f5(x, ...a) { arguments[0] = 0; return x }
   assertEquals(6, f5(6, {}));
   function f6(x, ...a) { x = 2; return arguments[0] }
   assertEquals(6, f6(6, {}));
   function f7({a: x}) { x = 2; return arguments[0].a }
   assertEquals(5, f7({a: 5}));
   function f8(x, ...a) { a = []; return arguments[1] }
   assertEquals(6, f8(5, 6));
-  // TODO(rossberg, caitp): Add cases for default parameters.
 }());
 
 
 (function TestForInOfTDZ() {
   assertThrows("'use strict'; let x = {}; for (let [x, y] of {x});", ReferenceError);
   assertThrows("'use strict'; let x = {}; for (let [y, x] of {x});", ReferenceError);
   assertThrows("'use strict'; let x = {}; for (let [x, y] in {x});", ReferenceError);
   assertThrows("'use strict'; let x = {}; for (let [y, x] in {x});", ReferenceError);
 }());