[proxies] Implement [[Enumerate]] and [[OwnPropertyKeys]]

test/mjsunit/harmony/proxies-ownkeys.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-proxies --harmony-reflect
+
+var target = {
+  "target_one": 1
+};
+target.__proto__ = {
+  "target_proto_two": 2
+};
+var handler = {
+  ownKeys: function(target) {
+    return ["foo", "bar"];
+  }
+}
+
+var proxy = new Proxy(target, handler);
+
+// Simple case.
+assertEquals(["foo", "bar"], Reflect.ownKeys(proxy));
+
+// Test interesting steps of the algorithm:
+
+// Step 6: Fall through to target.[[OwnPropertyKeys]] if the trap is undefined.
+handler.ownKeys = undefined;
+assertEquals(["target_one"], Reflect.ownKeys(proxy));
+
+// Step 7: Throwing traps don't crash.
+handler.ownKeys = function(target) { throw 1; };
+assertThrows("Reflect.ownKeys(proxy)");
+
+// Step 8: CreateListFromArrayLike error cases:
+// Returning a non-Object throws.
+var keys = 1;
+handler.ownKeys = function(target) { return keys; };
+assertThrows("Reflect.ownKeys(proxy)", TypeError);
+keys = "string";
+assertThrows("Reflect.ownKeys(proxy)", TypeError);
+keys = Symbol("foo");
+assertThrows("Reflect.ownKeys(proxy)", TypeError);
+keys = null;
+assertThrows("Reflect.ownKeys(proxy)", TypeError);
+
+// "length" property is honored.
+keys = { 0: "a", 1: "b", 2: "c" };
+keys.length = 0;
+assertEquals([], Reflect.ownKeys(proxy));
+keys.length = 1;
+assertEquals(["a"], Reflect.ownKeys(proxy));
+keys.length = 3;
+assertEquals(["a", "b", "c"], Reflect.ownKeys(proxy));
+// The spec wants to allow lengths up to 2^53, but we can't allocate arrays
+// of that size, so we throw even for smaller values.
+keys.length = Math.pow(2, 33);
+assertThrows("Reflect.ownKeys(proxy)", RangeError);
+
+// Non-Name results throw.
+keys = [1];
+assertThrows("Reflect.ownKeys(proxy)", TypeError);
+keys = [{}];
+assertThrows("Reflect.ownKeys(proxy)", TypeError);
+keys = [{toString: function() { return "foo"; }}];
+assertThrows("Reflect.ownKeys(proxy)", TypeError);
+keys = [null];
+assertThrows("Reflect.ownKeys(proxy)", TypeError);
+
+// Step 17a: The trap result must include all non-configurable keys.
+Object.defineProperty(target, "nonconf", {value: 1, configurable: false});
+keys = ["foo"];
+assertThrows("Reflect.ownKeys(proxy)", TypeError);
+keys = ["nonconf"];
+assertEquals(keys, Reflect.ownKeys(proxy));
+
+// Step 19a: The trap result must all keys of a non-extensible target.
+Object.freeze(target);
+assertThrows("Reflect.ownKeys(proxy)", TypeError);
+keys = ["nonconf", "target_one"];
+assertEquals(keys, Reflect.ownKeys(proxy));
+
+// Step 20: The trap result must not add keys to a non-extensible target.
+keys = ["nonconf", "target_one", "fantasy"];
+assertThrows("Reflect.ownKeys(proxy)", TypeError);