v8/test/mjsunit/es6/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.

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);

// Check that we allow duplicated keys.
keys  = ['a', 'a', 'a']
assertEquals(keys, Reflect.ownKeys(proxy));

// 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));

// Check that we allow duplicated keys.
keys  = ['nonconf', 'nonconf', 'nonconf']
assertEquals(keys, Reflect.ownKeys(proxy));

// Step 19a: The trap result must all keys of a non-extensible target.
Object.preventExtensions(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);

// Check that we allow duplicated keys.
keys  = ['nonconf', 'target_one', 'nonconf', 'nonconf', 'target_one',]
assertEquals(keys, Reflect.ownKeys(proxy));