[keys] Trigger [[getOwnPropertyDescriptor]] trap for Object.keys

test/mjsunit/es6/proxies-keys.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.
 
-var target = {
-  target: 1
-};
-target.__proto__ = {
-  target_proto: 2
-};
+(function testObjectKeys() {
+  var target = {
+    target: 1
+  };
+  target.__proto__ = {
+    target_proto: 2
+  };
 
-var handler = {
-  ownKeys: function(target) {
-    return ["foo", "bar", Symbol("baz"), "non-enum", "not-found"];
-  },
-  getOwnPropertyDescriptor: function(target, name) {
-    if (name == "non-enum") return {configurable: true};
-    if (name == "not-found") return undefined;
-    return {enumerable: true, configurable: true};
+  var handler = {
+    ownKeys: function(target) {
+      return ["foo", "bar", Symbol("baz"), "non-enum", "not-found"];
+    },
+    getOwnPropertyDescriptor: function(target, name) {
+      if (name == "non-enum") return {configurable: true};
+      if (name == "not-found") return undefined;
+      return {enumerable: true, configurable: true};
+    }
   }
-}
 
-var proxy = new Proxy(target, handler);
+  var proxy = new Proxy(target, handler);
 
-// Object.keys() ignores symbols and non-enumerable keys.
-assertEquals(["foo", "bar"], Object.keys(proxy));
+  // Object.keys() ignores symbols and non-enumerable keys.
+  assertEquals(["foo", "bar"], Object.keys(proxy));
 
-// Edge case: no properties left after filtering.
-handler.getOwnPropertyDescriptor = undefined;
-assertEquals([], Object.keys(proxy));
+  // Edge case: no properties left after filtering.
+  handler.getOwnPropertyDescriptor = undefined;
+  assertEquals([], Object.keys(proxy));
 
-// Throwing shouldn't crash.
-handler.getOwnPropertyDescriptor = function() { throw new Number(1); };
-assertThrows("Object.keys(proxy)", Number);
+  // Throwing shouldn't crash.
+  handler.getOwnPropertyDescriptor = function() { throw new Number(1); };
+  assertThrows("Object.keys(proxy)", Number);
 
-// Fall through to target if there is no trap.
-handler.ownKeys = undefined;
-assertEquals(["target"], Object.keys(proxy));
-assertEquals(["target"], Object.keys(target));
+  // Fall through to target if there is no trap.

[adamk, 2016/07/29 21:09:30]

This comment should go below, and this comment should say "Fall through to
getOwnPropertyDescriptor if there is no trap"

+  handler.ownKeys = undefined;
+  assertThrows("Object.keys(proxy)", Number);
 
-var proxy2 = new Proxy(proxy, {});
-assertEquals(["target"], Object.keys(proxy2));
+  handler.getOwnPropertyDescriptor = undefined;
+  assertEquals(["target"], Object.keys(proxy));
+  assertEquals(["target"], Object.keys(target));
 
+  var proxy2 = new Proxy(proxy, {});
+  assertEquals(["target"], Object.keys(proxy2));
+})();
 
 (function testForSymbols() {
   var symbol = Symbol();
   var p = new Proxy({}, {ownKeys() { return ["1", symbol, "2"] }});
   assertEquals(["1","2"], Object.getOwnPropertyNames(p));
   assertEquals([symbol], Object.getOwnPropertySymbols(p));
 })();
 
 (function testNoProxyTraps() {
   var test_sym = Symbol("sym1");
@@ skipping 15 matching lines @@
   Object.defineProperty(
       target.__proto__, "non-enum2",
       { enumerable: false, value: "nope", configurable: true, writable: true });
   var proxy = new Proxy(target, {});
 
   assertEquals(["0", "one", "two"], Object.keys(proxy));
   assertEquals(["0", "one", "two", "non-enum"],
                Object.getOwnPropertyNames(proxy));
   assertEquals([test_sym], Object.getOwnPropertySymbols(proxy));
 })();