v8/test/mjsunit/object-define-property.js

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// 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.defineProperty method - ES 15.2.3.6
// Flags: --allow-natives-syntax
// Check that an exception is thrown when null is passed as object.
try {
Object.defineProperty(null, null, null);
assertTrue(false);
} catch (e) {
assertTrue(/called on non-object/.test(e));
}
// Check that an exception is thrown when undefined is passed as object.
try {
Object.defineProperty(undefined, undefined, undefined);
assertTrue(false);
} catch (e) {
assertTrue(/called on non-object/.test(e));
}
// Check that an exception is thrown when non-object is passed as object.
try {
Object.defineProperty(0, "foo", undefined);
assertTrue(false);
} catch (e) {
assertTrue(/called on non-object/.test(e));
}
// Object.
var obj1 = {};
// Values.
var val1 = 0;
var val2 = 0;
var val3 = 0;
function setter1() {val1++; }
function getter1() {return val1; }
function setter2() {val2++; }
function getter2() {return val2; }
function setter3() {val3++; }
function getter3() {return val3; }
// Descriptors.
var emptyDesc = {};
var accessorConfigurable = {
set: setter1,
get: getter1,
configurable: true
};
var accessorNoConfigurable = {
set: setter2,
get: getter2,
configurable: false
};
var accessorOnlySet = {
set: setter3,
configurable: true
};
var accessorOnlyGet = {
get: getter3,
configurable: true
};
var accessorDefault = {set: function(){} };
var dataConfigurable = { value: 1000, configurable: true };
var dataNoConfigurable = { value: 2000, configurable: false };
var dataWritable = { value: 3000, writable: true};
// Check that we can't add property with undefined attributes.
try {
Object.defineProperty(obj1, "foo", undefined);
assertTrue(false);
} catch (e) {
assertTrue(/must be an object/.test(e));
}
// Make sure that we can add a property with an empty descriptor and
// that it has the default descriptor values.
Object.defineProperty(obj1, "foo", emptyDesc);
// foo should be undefined as it has no get, set or value
assertEquals(undefined, obj1.foo);
// We should, however, be able to retrieve the propertydescriptor which should
// have all default values (according to 8.6.1).
var desc = Object.getOwnPropertyDescriptor(obj1, "foo");
assertFalse(desc.configurable);
assertFalse(desc.enumerable);
assertFalse(desc.writable);
assertEquals(desc.get, undefined);
assertEquals(desc.set, undefined);
assertEquals(desc.value, undefined);
// Make sure that getOwnPropertyDescriptor does not return a descriptor
// with default values if called with non existing property (otherwise
// the test above is invalid).
desc = Object.getOwnPropertyDescriptor(obj1, "bar");
assertEquals(desc, undefined);
// Make sure that foo can't be reset (as configurable is false).
try {
Object.defineProperty(obj1, "foo", accessorConfigurable);
} catch (e) {
assertTrue(/Cannot redefine property/.test(e));
}
// Accessor properties
Object.defineProperty(obj1, "bar", accessorConfigurable);
desc = Object.getOwnPropertyDescriptor(obj1, "bar");
assertTrue(desc.configurable);
assertFalse(desc.enumerable);
assertEquals(desc.writable, undefined);
assertEquals(desc.get, accessorConfigurable.get);
assertEquals(desc.set, accessorConfigurable.set);
assertEquals(desc.value, undefined);
assertEquals(1, obj1.bar = 1);
assertEquals(1, val1);
assertEquals(1, obj1.bar = 1);
assertEquals(2, val1);
assertEquals(2, obj1.bar);
// Redefine bar with non configurable test
Object.defineProperty(obj1, "bar", accessorNoConfigurable);
desc = Object.getOwnPropertyDescriptor(obj1, "bar");
assertFalse(desc.configurable);
assertFalse(desc.enumerable);
assertEquals(desc.writable, undefined);
assertEquals(desc.get, accessorNoConfigurable.get);
assertEquals(desc.set, accessorNoConfigurable.set);
assertEquals(desc.value, undefined);
assertEquals(1, obj1.bar = 1);
assertEquals(2, val1);
assertEquals(1, val2);
assertEquals(1, obj1.bar = 1)
assertEquals(2, val1);
assertEquals(2, val2);
assertEquals(2, obj1.bar);
// Try to redefine bar again - should fail as configurable is false.
try {
Object.defineProperty(obj1, "bar", accessorConfigurable);
assertTrue(false);
} catch(e) {
assertTrue(/Cannot redefine property/.test(e));
}
// Try to redefine bar again using the data descriptor - should fail.
try {
Object.defineProperty(obj1, "bar", dataConfigurable);
assertTrue(false);
} catch(e) {
assertTrue(/Cannot redefine property/.test(e));
}
// Redefine using same descriptor - should succeed.
Object.defineProperty(obj1, "bar", accessorNoConfigurable);
desc = Object.getOwnPropertyDescriptor(obj1, "bar");
assertFalse(desc.configurable);
assertFalse(desc.enumerable);
assertEquals(desc.writable, undefined);
assertEquals(desc.get, accessorNoConfigurable.get);
assertEquals(desc.set, accessorNoConfigurable.set);
assertEquals(desc.value, undefined);
assertEquals(1, obj1.bar = 1);
assertEquals(2, val1);
assertEquals(3, val2);
assertEquals(1, obj1.bar = 1)
assertEquals(2, val1);
assertEquals(4, val2);
assertEquals(4, obj1.bar);
// Define an accessor that has only a setter.
Object.defineProperty(obj1, "setOnly", accessorOnlySet);
desc = Object.getOwnPropertyDescriptor(obj1, "setOnly");
assertTrue(desc.configurable);
assertFalse(desc.enumerable);
assertEquals(desc.set, accessorOnlySet.set);
assertEquals(desc.writable, undefined);
assertEquals(desc.value, undefined);
assertEquals(desc.get, undefined);
assertEquals(1, obj1.setOnly = 1);
assertEquals(1, val3);
// Add a getter - should not touch the setter.
Object.defineProperty(obj1, "setOnly", accessorOnlyGet);
desc = Object.getOwnPropertyDescriptor(obj1, "setOnly");
assertTrue(desc.configurable);
assertFalse(desc.enumerable);
assertEquals(desc.get, accessorOnlyGet.get);
assertEquals(desc.set, accessorOnlySet.set);
assertEquals(desc.writable, undefined);
assertEquals(desc.value, undefined);
assertEquals(1, obj1.setOnly = 1);
assertEquals(2, val3);
// The above should also work if redefining just a getter or setter on
// an existing property with both a getter and a setter.
Object.defineProperty(obj1, "both", accessorConfigurable);
Object.defineProperty(obj1, "both", accessorOnlySet);
desc = Object.getOwnPropertyDescriptor(obj1, "both");
assertTrue(desc.configurable);
assertFalse(desc.enumerable);
assertEquals(desc.set, accessorOnlySet.set);
assertEquals(desc.get, accessorConfigurable.get);
assertEquals(desc.writable, undefined);
assertEquals(desc.value, undefined);
assertEquals(1, obj1.both = 1);
assertEquals(3, val3);
// Data properties
Object.defineProperty(obj1, "foobar", dataConfigurable);
desc = Object.getOwnPropertyDescriptor(obj1, "foobar");
assertEquals(obj1.foobar, 1000);
assertEquals(desc.value, 1000);
assertTrue(desc.configurable);
assertFalse(desc.writable);
assertFalse(desc.enumerable);
assertEquals(desc.get, undefined);
assertEquals(desc.set, undefined);
//Try writing to non writable attribute - should remain 1000
obj1.foobar = 1001;
assertEquals(obj1.foobar, 1000);
// Redefine to writable descriptor - now writing to foobar should be allowed.
Object.defineProperty(obj1, "foobar", dataWritable);
desc = Object.getOwnPropertyDescriptor(obj1, "foobar");
assertEquals(obj1.foobar, 3000);
assertEquals(desc.value, 3000);
// Note that since dataWritable does not define configurable the configurable
// setting from the redefined property (in this case true) is used.
assertTrue(desc.configurable);
assertTrue(desc.writable);
assertFalse(desc.enumerable);
assertEquals(desc.get, undefined);
assertEquals(desc.set, undefined);
// Writing to the property should now be allowed
obj1.foobar = 1001;
assertEquals(obj1.foobar, 1001);
// Redefine with non configurable data property.
Object.defineProperty(obj1, "foobar", dataNoConfigurable);
desc = Object.getOwnPropertyDescriptor(obj1, "foobar");
assertEquals(obj1.foobar, 2000);
assertEquals(desc.value, 2000);
assertFalse(desc.configurable);
assertTrue(desc.writable);
assertFalse(desc.enumerable);
assertEquals(desc.get, undefined);
assertEquals(desc.set, undefined);
// Try redefine again - shold fail because configurable is now false.
try {
Object.defineProperty(obj1, "foobar", dataConfigurable);
assertTrue(false);
} catch (e) {
assertTrue(/Cannot redefine property/.test(e));
}
// Try redefine again with accessor property - shold also fail.
try {
Object.defineProperty(obj1, "foobar", dataConfigurable);
assertTrue(false);
} catch (e) {
assertTrue(/Cannot redefine property/.test(e));
}
// Redifine with the same descriptor - should succeed (step 6).
Object.defineProperty(obj1, "foobar", dataNoConfigurable);
desc = Object.getOwnPropertyDescriptor(obj1, "foobar");
assertEquals(obj1.foobar, 2000);
assertEquals(desc.value, 2000);
assertFalse(desc.configurable);
assertTrue(desc.writable);
assertFalse(desc.enumerable);
assertEquals(desc.get, undefined);
assertEquals(desc.set, undefined);
// New object
var obj2 = {};
// Make accessor - redefine to data
Object.defineProperty(obj2, "foo", accessorConfigurable);
// Redefine to data property
Object.defineProperty(obj2, "foo", dataConfigurable);
desc = Object.getOwnPropertyDescriptor(obj2, "foo");
assertEquals(obj2.foo, 1000);
assertEquals(desc.value, 1000);
assertTrue(desc.configurable);
assertFalse(desc.writable);
assertFalse(desc.enumerable);
assertEquals(desc.get, undefined);
assertEquals(desc.set, undefined);
// Redefine back to accessor
Object.defineProperty(obj2, "foo", accessorConfigurable);
desc = Object.getOwnPropertyDescriptor(obj2, "foo");
assertTrue(desc.configurable);
assertFalse(desc.enumerable);
assertEquals(desc.writable, undefined);
assertEquals(desc.get, accessorConfigurable.get);
assertEquals(desc.set, accessorConfigurable.set);
assertEquals(desc.value, undefined);
assertEquals(1, obj2.foo = 1);
assertEquals(3, val1);
assertEquals(4, val2);
assertEquals(3, obj2.foo);
// Make data - redefine to accessor
Object.defineProperty(obj2, "bar", dataConfigurable)
// Redefine to accessor property
Object.defineProperty(obj2, "bar", accessorConfigurable);
desc = Object.getOwnPropertyDescriptor(obj2, "bar");
assertTrue(desc.configurable);
assertFalse(desc.enumerable);
assertEquals(desc.writable, undefined);
assertEquals(desc.get, accessorConfigurable.get);
assertEquals(desc.set, accessorConfigurable.set);
assertEquals(desc.value, undefined);
assertEquals(1, obj2.bar = 1);
assertEquals(4, val1);
assertEquals(4, val2);
assertEquals(4, obj2.foo);
// Redefine back to data property
Object.defineProperty(obj2, "bar", dataConfigurable);
desc = Object.getOwnPropertyDescriptor(obj2, "bar");
assertEquals(obj2.bar, 1000);
assertEquals(desc.value, 1000);
assertTrue(desc.configurable);
assertFalse(desc.writable);
assertFalse(desc.enumerable);
assertEquals(desc.get, undefined);
assertEquals(desc.set, undefined);
// Redefinition of an accessor defined using __defineGetter__ and
// __defineSetter__.
function get(){return this.x}
function set(x){this.x=x};
var obj3 = {x:1000};
obj3.__defineGetter__("foo", get);
obj3.__defineSetter__("foo", set);
desc = Object.getOwnPropertyDescriptor(obj3, "foo");
assertTrue(desc.configurable);
assertTrue(desc.enumerable);
assertEquals(desc.writable, undefined);
assertEquals(desc.get, get);
assertEquals(desc.set, set);
assertEquals(desc.value, undefined);
assertEquals(1, obj3.foo = 1);
assertEquals(1, obj3.x);
assertEquals(1, obj3.foo);
// Redefine to accessor property (non configurable) - note that enumerable
// which we do not redefine should remain the same (true).
Object.defineProperty(obj3, "foo", accessorNoConfigurable);
desc = Object.getOwnPropertyDescriptor(obj3, "foo");
assertFalse(desc.configurable);
assertTrue(desc.enumerable);
assertEquals(desc.writable, undefined);
assertEquals(desc.get, accessorNoConfigurable.get);
assertEquals(desc.set, accessorNoConfigurable.set);
assertEquals(desc.value, undefined);
assertEquals(1, obj3.foo = 1);
assertEquals(5, val2);
assertEquals(5, obj3.foo);
obj3.__defineGetter__("bar", get);
obj3.__defineSetter__("bar", set);
// Redefine back to data property
Object.defineProperty(obj3, "bar", dataConfigurable);
desc = Object.getOwnPropertyDescriptor(obj3, "bar");
assertEquals(obj3.bar, 1000);
assertEquals(desc.value, 1000);
assertTrue(desc.configurable);
assertFalse(desc.writable);
assertTrue(desc.enumerable);
assertEquals(desc.get, undefined);
assertEquals(desc.set, undefined);
var obj4 = {};
var func = function (){return 42;};
obj4.bar = func;
assertEquals(42, obj4.bar());
Object.defineProperty(obj4, "bar", accessorConfigurable);
desc = Object.getOwnPropertyDescriptor(obj4, "bar");
assertTrue(desc.configurable);
assertTrue(desc.enumerable);
assertEquals(desc.writable, undefined);
assertEquals(desc.get, accessorConfigurable.get);
assertEquals(desc.set, accessorConfigurable.set);
assertEquals(desc.value, undefined);
assertEquals(1, obj4.bar = 1);
assertEquals(5, val1);
assertEquals(5, obj4.bar);
// Make sure an error is thrown when trying to access to redefined function.
try {
obj4.bar();
assertTrue(false);
} catch (e) {
assertTrue(/is not a function/.test(e));
}
// Test runtime calls to DefineOrRedefineDataProperty and
// DefineOrRedefineAccessorProperty - make sure we don't
// crash.
try {
%DefineOrRedefineAccessorProperty(0, 0, 0, 0, 0);
} catch (e) {
assertTrue(/illegal access/.test(e));
}
try {
%DefineOrRedefineDataProperty(0, 0, 0, 0);
} catch (e) {
assertTrue(/illegal access/.test(e));
}
try {
%DefineOrRedefineDataProperty(null, null, null, null);
} catch (e) {
assertTrue(/illegal access/.test(e));
}
try {
%DefineOrRedefineAccessorProperty(null, null, null, null, null);
} catch (e) {
assertTrue(/illegal access/.test(e));
}
try {
%DefineOrRedefineDataProperty({}, null, null, null);
} catch (e) {
assertTrue(/illegal access/.test(e));
}
// Defining properties null should fail even when we have
// other allowed values
try {
%DefineOrRedefineAccessorProperty(null, 'foo', 0, func, 0);
} catch (e) {
assertTrue(/illegal access/.test(e));
}
try {
%DefineOrRedefineDataProperty(null, 'foo', 0, 0);
} catch (e) {
assertTrue(/illegal access/.test(e));
}
// Test that all possible differences in step 6 in DefineOwnProperty are
// exercised, i.e., any difference in the given property descriptor and the
// existing properties should not return true, but throw an error if the
// existing configurable property is false.
var obj5 = {};
// Enumerable will default to false.
Object.defineProperty(obj5, 'foo', accessorNoConfigurable);
desc = Object.getOwnPropertyDescriptor(obj5, 'foo');
// First, test that we are actually allowed to set the accessor if all
// values are of the descriptor are the same as the existing one.
Object.defineProperty(obj5, 'foo', accessorNoConfigurable);
// Different setter.
var descDifferent = {
configurable:false,
enumerable:false,
set: setter1,
get: getter2
};
try {
Object.defineProperty(obj5, 'foo', descDifferent);
assertTrue(false);
} catch (e) {
assertTrue(/Cannot redefine property/.test(e));
}
// Different getter.
descDifferent = {
configurable:false,
enumerable:false,
set: setter2,
get: getter1
};
try {
Object.defineProperty(obj5, 'foo', descDifferent);
assertTrue(false);
} catch (e) {
assertTrue(/Cannot redefine property/.test(e));
}
// Different enumerable.
descDifferent = {
configurable:false,
enumerable:true,
set: setter2,
get: getter2
};
try {
Object.defineProperty(obj5, 'foo', descDifferent);
assertTrue(false);
} catch (e) {
assertTrue(/Cannot redefine property/.test(e));
}
// Different configurable.
descDifferent = {
configurable:false,
enumerable:true,
set: setter2,
get: getter2
};
try {
Object.defineProperty(obj5, 'foo', descDifferent);
assertTrue(false);
} catch (e) {
assertTrue(/Cannot redefine property/.test(e));
}
// No difference.
descDifferent = {
configurable:false,
enumerable:false,
set: setter2,
get: getter2
};
// Make sure we can still redefine if all properties are the same.
Object.defineProperty(obj5, 'foo', descDifferent);
// Make sure that obj5 still holds the original values.
desc = Object.getOwnPropertyDescriptor(obj5, 'foo');
assertEquals(desc.get, getter2);
assertEquals(desc.set, setter2);
assertFalse(desc.enumerable);
assertFalse(desc.configurable);
// Also exercise step 6 on data property, writable and enumerable
// defaults to false.
Object.defineProperty(obj5, 'bar', dataNoConfigurable);
// Test that redefinition with the same property descriptor is possible
Object.defineProperty(obj5, 'bar', dataNoConfigurable);
// Different value.
descDifferent = {
configurable:false,
enumerable:false,
writable: false,
value: 1999
};
try {
Object.defineProperty(obj5, 'bar', descDifferent);
assertTrue(false);
} catch (e) {
assertTrue(/Cannot redefine property/.test(e));
}
// Different writable.
descDifferent = {
configurable:false,
enumerable:false,
writable: true,
value: 2000
};
try {
Object.defineProperty(obj5, 'bar', descDifferent);
assertTrue(false);
} catch (e) {
assertTrue(/Cannot redefine property/.test(e));
}
// Different enumerable.
descDifferent = {
configurable:false,
enumerable:true ,
writable:false,
value: 2000
};
try {
Object.defineProperty(obj5, 'bar', descDifferent);
assertTrue(false);
} catch (e) {
assertTrue(/Cannot redefine property/.test(e));
}
// Different configurable.
descDifferent = {
configurable:true,
enumerable:false,
writable:false,
value: 2000
};
try {
Object.defineProperty(obj5, 'bar', descDifferent);
assertTrue(false);
} catch (e) {
assertTrue(/Cannot redefine property/.test(e));
}
// No difference.
descDifferent = {
configurable:false,
enumerable:false,
writable:false,
value:2000
};
// Make sure we can still redefine if all properties are the same.
Object.defineProperty(obj5, 'bar', descDifferent);
// Make sure that obj5 still holds the original values.
desc = Object.getOwnPropertyDescriptor(obj5, 'bar');
assertEquals(desc.value, 2000);
assertFalse(desc.writable);
assertFalse(desc.enumerable);
assertFalse(desc.configurable);
// Make sure that we can't overwrite +0 with -0 and vice versa.
var descMinusZero = {value: -0, configurable: false};
var descPlusZero = {value: +0, configurable: false};
Object.defineProperty(obj5, 'minuszero', descMinusZero);
// Make sure we can redefine with -0.
Object.defineProperty(obj5, 'minuszero', descMinusZero);
try {
Object.defineProperty(obj5, 'minuszero', descPlusZero);
assertUnreachable();
} catch (e) {
assertTrue(/Cannot redefine property/.test(e));
}
Object.defineProperty(obj5, 'pluszero', descPlusZero);
// Make sure we can redefine with +0.
Object.defineProperty(obj5, 'pluszero', descPlusZero);
try {
Object.defineProperty(obj5, 'pluszero', descMinusZero);
assertUnreachable();
} catch (e) {
assertTrue(/Cannot redefine property/.test(e));
}
var obj6 = {};
obj6[1] = 'foo';
obj6[2] = 'bar';
obj6[3] = '42';
obj6[4] = '43';
obj6[5] = '44';
var descElement = { value: 'foobar' };
var descElementNonConfigurable = { value: 'barfoo', configurable: false };
var descElementNonWritable = { value: 'foofoo', writable: false };
var descElementNonEnumerable = { value: 'barbar', enumerable: false };
var descElementAllFalse = { value: 'foofalse',
configurable: false,
writable: false,
enumerable: false };
// Redefine existing property.
Object.defineProperty(obj6, '1', descElement);
desc = Object.getOwnPropertyDescriptor(obj6, '1');
assertEquals(desc.value, 'foobar');
assertTrue(desc.writable);
assertTrue(desc.enumerable);
assertTrue(desc.configurable);
// Redefine existing property with configurable: false.
Object.defineProperty(obj6, '2', descElementNonConfigurable);
desc = Object.getOwnPropertyDescriptor(obj6, '2');
assertEquals(desc.value, 'barfoo');
assertTrue(desc.writable);
assertTrue(desc.enumerable);
assertFalse(desc.configurable);
// Can use defineProperty to change the value of a non
// configurable property.
try {
Object.defineProperty(obj6, '2', descElement);
desc = Object.getOwnPropertyDescriptor(obj6, '2');
assertEquals(desc.value, 'foobar');
} catch (e) {
assertUnreachable();
}
// Ensure that we can't change the descriptor of a
// non configurable property.
try {
var descAccessor = { get: function() { return 0; } };
Object.defineProperty(obj6, '2', descAccessor);
assertUnreachable();
} catch (e) {
assertTrue(/Cannot redefine property/.test(e));
}
Object.defineProperty(obj6, '2', descElementNonWritable);
desc = Object.getOwnPropertyDescriptor(obj6, '2');
assertEquals(desc.value, 'foofoo');
assertFalse(desc.writable);
assertTrue(desc.enumerable);
assertFalse(desc.configurable);
Object.defineProperty(obj6, '3', descElementNonWritable);
desc = Object.getOwnPropertyDescriptor(obj6, '3');
assertEquals(desc.value, 'foofoo');
assertFalse(desc.writable);
assertTrue(desc.enumerable);
assertTrue(desc.configurable);
// Redefine existing property with configurable: false.
Object.defineProperty(obj6, '4', descElementNonEnumerable);
desc = Object.getOwnPropertyDescriptor(obj6, '4');
assertEquals(desc.value, 'barbar');
assertTrue(desc.writable);
assertFalse(desc.enumerable);
assertTrue(desc.configurable);
// Redefine existing property with configurable: false.
Object.defineProperty(obj6, '5', descElementAllFalse);
desc = Object.getOwnPropertyDescriptor(obj6, '5');
assertEquals(desc.value, 'foofalse');
assertFalse(desc.writable);
assertFalse(desc.enumerable);
assertFalse(desc.configurable);
// Define non existing property - all attributes should default to false.
Object.defineProperty(obj6, '15', descElement);
desc = Object.getOwnPropertyDescriptor(obj6, '15');
assertEquals(desc.value, 'foobar');
assertFalse(desc.writable);
assertFalse(desc.enumerable);
assertFalse(desc.configurable);
// Make sure that we can't redefine using direct access.
obj6[15] ='overwrite';
assertEquals(obj6[15],'foobar');
// Repeat the above tests on an array.
var arr = new Array();
arr[1] = 'foo';
arr[2] = 'bar';
arr[3] = '42';
arr[4] = '43';
arr[5] = '44';
var descElement = { value: 'foobar' };
var descElementNonConfigurable = { value: 'barfoo', configurable: false };
var descElementNonWritable = { value: 'foofoo', writable: false };
var descElementNonEnumerable = { value: 'barbar', enumerable: false };
var descElementAllFalse = { value: 'foofalse',
configurable: false,
writable: false,
enumerable: false };
// Redefine existing property.
Object.defineProperty(arr, '1', descElement);
desc = Object.getOwnPropertyDescriptor(arr, '1');
assertEquals(desc.value, 'foobar');
assertTrue(desc.writable);
assertTrue(desc.enumerable);
assertTrue(desc.configurable);
// Redefine existing property with configurable: false.
Object.defineProperty(arr, '2', descElementNonConfigurable);
desc = Object.getOwnPropertyDescriptor(arr, '2');
assertEquals(desc.value, 'barfoo');
assertTrue(desc.writable);
assertTrue(desc.enumerable);
assertFalse(desc.configurable);
// Can use defineProperty to change the value of a non
// configurable property of an array.
try {
Object.defineProperty(arr, '2', descElement);
desc = Object.getOwnPropertyDescriptor(arr, '2');
assertEquals(desc.value, 'foobar');
} catch (e) {
assertUnreachable();
}
// Ensure that we can't change the descriptor of a
// non configurable property.
try {
var descAccessor = { get: function() { return 0; } };
Object.defineProperty(arr, '2', descAccessor);
assertUnreachable();
} catch (e) {
assertTrue(/Cannot redefine property/.test(e));
}
Object.defineProperty(arr, '2', descElementNonWritable);
desc = Object.getOwnPropertyDescriptor(arr, '2');
assertEquals(desc.value, 'foofoo');
assertFalse(desc.writable);
assertTrue(desc.enumerable);
assertFalse(desc.configurable);
Object.defineProperty(arr, '3', descElementNonWritable);
desc = Object.getOwnPropertyDescriptor(arr, '3');
assertEquals(desc.value, 'foofoo');
assertFalse(desc.writable);
assertTrue(desc.enumerable);
assertTrue(desc.configurable);
// Redefine existing property with configurable: false.
Object.defineProperty(arr, '4', descElementNonEnumerable);
desc = Object.getOwnPropertyDescriptor(arr, '4');
assertEquals(desc.value, 'barbar');
assertTrue(desc.writable);
assertFalse(desc.enumerable);
assertTrue(desc.configurable);
// Redefine existing property with configurable: false.
Object.defineProperty(arr, '5', descElementAllFalse);
desc = Object.getOwnPropertyDescriptor(arr, '5');
assertEquals(desc.value, 'foofalse');
assertFalse(desc.writable);
assertFalse(desc.enumerable);
assertFalse(desc.configurable);
// Define non existing property - all attributes should default to false.
Object.defineProperty(arr, '15', descElement);
desc = Object.getOwnPropertyDescriptor(arr, '15');
assertEquals(desc.value, 'foobar');
assertFalse(desc.writable);
assertFalse(desc.enumerable);
assertFalse(desc.configurable);
// See issue 968: http://code.google.com/p/v8/issues/detail?id=968
var o = { x : 42 };
Object.defineProperty(o, "x", { writable: false });
assertEquals(42, o.x);
o.x = 37;
assertEquals(42, o.x);
o = { x : 42 };
Object.defineProperty(o, "x", {});
assertEquals(42, o.x);
o.x = 37;
// Writability is preserved.
assertEquals(37, o.x);
var o = { };
Object.defineProperty(o, "x", { writable: false });
assertEquals(undefined, o.x);
o.x = 37;
assertEquals(undefined, o.x);
o = { get x() { return 87; } };
Object.defineProperty(o, "x", { writable: false });
assertEquals(undefined, o.x);
o.x = 37;
assertEquals(undefined, o.x);
// Ignore inherited properties.
o = { __proto__ : { x : 87 } };
Object.defineProperty(o, "x", { writable: false });
assertEquals(undefined, o.x);
o.x = 37;
assertEquals(undefined, o.x);
function testDefineProperty(obj, propertyName, desc, resultDesc) {
Object.defineProperty(obj, propertyName, desc);
var actualDesc = Object.getOwnPropertyDescriptor(obj, propertyName);
assertEquals(resultDesc.enumerable, actualDesc.enumerable);
assertEquals(resultDesc.configurable, actualDesc.configurable);
if (resultDesc.hasOwnProperty('value')) {
assertEquals(resultDesc.value, actualDesc.value);
assertEquals(resultDesc.writable, actualDesc.writable);
assertFalse(resultDesc.hasOwnProperty('get'));
assertFalse(resultDesc.hasOwnProperty('set'));
} else {
assertEquals(resultDesc.get, actualDesc.get);
assertEquals(resultDesc.set, actualDesc.set);
assertFalse(resultDesc.hasOwnProperty('value'));
assertFalse(resultDesc.hasOwnProperty('writable'));
}
}
// tests redefining existing property with a generic descriptor
o = { p : 42 };
testDefineProperty(o, 'p',
{ },
{ value : 42, writable : true, enumerable : true, configurable : true });
o = { p : 42 };
testDefineProperty(o, 'p',
{ enumerable : true },
{ value : 42, writable : true, enumerable : true, configurable : true });
o = { p : 42 };
testDefineProperty(o, 'p',
{ configurable : true },
{ value : 42, writable : true, enumerable : true, configurable : true });
o = { p : 42 };
testDefineProperty(o, 'p',
{ enumerable : false },
{ value : 42, writable : true, enumerable : false, configurable : true });
o = { p : 42 };
testDefineProperty(o, 'p',
{ configurable : false },
{ value : 42, writable : true, enumerable : true, configurable : false });
o = { p : 42 };
testDefineProperty(o, 'p',
{ enumerable : true, configurable : true },
{ value : 42, writable : true, enumerable : true, configurable : true });
o = { p : 42 };
testDefineProperty(o, 'p',
{ enumerable : false, configurable : true },
{ value : 42, writable : true, enumerable : false, configurable : true });
o = { p : 42 };
testDefineProperty(o, 'p',
{ enumerable : true, configurable : false },
{ value : 42, writable : true, enumerable : true, configurable : false });
o = { p : 42 };
testDefineProperty(o, 'p',
{ enumerable : false, configurable : false },
{ value : 42, writable : true, enumerable : false, configurable : false });
// can make a writable, non-configurable field non-writable
o = { p : 42 };
Object.defineProperty(o, 'p', { configurable: false });
testDefineProperty(o, 'p',
{ writable: false },
{ value : 42, writable : false, enumerable : true, configurable : false });
// redefine of get only property with generic descriptor
o = {};
Object.defineProperty(o, 'p',
{ get : getter1, enumerable: true, configurable: true });
testDefineProperty(o, 'p',
{ enumerable : false, configurable : false },
{ get: getter1, set: undefined, enumerable : false, configurable : false });
// redefine of get/set only property with generic descriptor
o = {};
Object.defineProperty(o, 'p',
{ get: getter1, set: setter1, enumerable: true, configurable: true });
testDefineProperty(o, 'p',
{ enumerable : false, configurable : false },
{ get: getter1, set: setter1, enumerable : false, configurable : false });
// redefine of set only property with generic descriptor
o = {};
Object.defineProperty(o, 'p',
{ set : setter1, enumerable: true, configurable: true });
testDefineProperty(o, 'p',
{ enumerable : false, configurable : false },
{ get: undefined, set: setter1, enumerable : false, configurable : false });