JezK
Edit File: object-seal.js
// Copyright 2010 the V8 project authors. All rights reserved. // Redistribution and use in source and binary forms, with or without // modification, are permitted provided that the following conditions are // met: // // * Redistributions of source code must retain the above copyright // notice, this list of conditions and the following disclaimer. // * Redistributions in binary form must reproduce the above // copyright notice, this list of conditions and the following // disclaimer in the documentation and/or other materials provided // with the distribution. // * Neither the name of Google Inc. nor the names of its // contributors may be used to endorse or promote products derived // from this software without specific prior written permission. // // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. // Tests the Object.seal and Object.isSealed methods - ES 15.2.3.9 and // ES 15.2.3.12 // Test that we throw an error if an object is not passed as argument. var non_objects = new Array(undefined, null, 1, -1, 0, 42.43); for (var key in non_objects) { var exception = false; try { Object.seal(non_objects[key]); } catch(e) { exception = true; assertTrue(/Object.seal called on non-object/.test(e)); } assertTrue(exception); } for (var key in non_objects) { exception = false; try { Object.isSealed(non_objects[key]); } catch(e) { exception = true; assertTrue(/Object.isSealed called on non-object/.test(e)); } assertTrue(exception); } // Test normal data properties. var obj = { x: 42, z: 'foobar' }; var desc = Object.getOwnPropertyDescriptor(obj, 'x'); assertTrue(desc.writable); assertTrue(desc.configurable); assertEquals(42, desc.value); desc = Object.getOwnPropertyDescriptor(obj, 'z'); assertTrue(desc.writable); assertTrue(desc.configurable); assertEquals('foobar', desc.value); assertTrue(Object.isExtensible(obj)); assertFalse(Object.isSealed(obj)); Object.seal(obj); // Make sure we are no longer extensible. assertFalse(Object.isExtensible(obj)); assertTrue(Object.isSealed(obj)); // We should not be frozen, since we are still able to // update values. assertFalse(Object.isFrozen(obj)); // We should not allow new properties to be added. obj.foo = 42; assertEquals(obj.foo, undefined); desc = Object.getOwnPropertyDescriptor(obj, 'x'); assertTrue(desc.writable); assertFalse(desc.configurable); assertEquals(42, desc.value); desc = Object.getOwnPropertyDescriptor(obj, 'z'); assertTrue(desc.writable); assertFalse(desc.configurable); assertEquals("foobar", desc.value); // Since writable is not affected by seal we should still be able to // update the values. obj.x = "43"; assertEquals("43", obj.x); // Test on accessors. var obj2 = {}; function get() { return 43; }; function set() {}; Object.defineProperty(obj2, 'x', { get: get, set: set, configurable: true }); desc = Object.getOwnPropertyDescriptor(obj2, 'x'); assertTrue(desc.configurable); assertEquals(undefined, desc.value); assertEquals(set, desc.set); assertEquals(get, desc.get); assertTrue(Object.isExtensible(obj2)); assertFalse(Object.isSealed(obj2)); Object.seal(obj2); // Since this is an accessor property the object is now effectively both // sealed and frozen (accessors has no writable attribute). assertTrue(Object.isFrozen(obj2)); assertFalse(Object.isExtensible(obj2)); assertTrue(Object.isSealed(obj2)); desc = Object.getOwnPropertyDescriptor(obj2, 'x'); assertFalse(desc.configurable); assertEquals(undefined, desc.value); assertEquals(set, desc.set); assertEquals(get, desc.get); obj2.foo = 42; assertEquals(obj2.foo, undefined); // Test seal on arrays. var arr = new Array(42,43); desc = Object.getOwnPropertyDescriptor(arr, '0'); assertTrue(desc.configurable); assertTrue(desc.writable); assertEquals(42, desc.value); desc = Object.getOwnPropertyDescriptor(arr, '1'); assertTrue(desc.configurable); assertTrue(desc.writable); assertEquals(43, desc.value); assertTrue(Object.isExtensible(arr)); assertFalse(Object.isSealed(arr)); Object.seal(arr); assertTrue(Object.isSealed(arr)); assertFalse(Object.isExtensible(arr)); // Since the values in the array is still writable this object // is not frozen. assertFalse(Object.isFrozen(arr)); desc = Object.getOwnPropertyDescriptor(arr, '0'); assertFalse(desc.configurable); assertTrue(desc.writable); assertEquals(42, desc.value); desc = Object.getOwnPropertyDescriptor(arr, '1'); assertFalse(desc.configurable); assertTrue(desc.writable); assertEquals(43, desc.value); arr[0] = 'foo'; // We should be able to overwrite the existing value. assertEquals('foo', arr[0]); // Test that isSealed returns the correct value even if configurable // has been set to false on all properties manually and the extensible // flag has also been set to false manually. var obj3 = { x: 42, y: 'foo' }; assertFalse(Object.isFrozen(obj3)); Object.defineProperty(obj3, 'x', {configurable: false, writable: true}); Object.defineProperty(obj3, 'y', {configurable: false, writable: false}); Object.preventExtensions(obj3); assertTrue(Object.isSealed(obj3)); // Make sure that an object that has a configurable property // is not classified as sealed. var obj4 = {}; Object.defineProperty(obj4, 'x', {configurable: true, writable: false}); Object.defineProperty(obj4, 'y', {configurable: false, writable: false}); Object.preventExtensions(obj4); assertFalse(Object.isSealed(obj4)); // Make sure that Object.seal returns the sealed object. var obj4 = {}; assertTrue(obj4 === Object.seal(obj4));