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load(libdir + "asserts.js");
function testNonExtensible() {
var a = [1, 2, 3, , 5];
Object.preventExtensions(a);
// Can change the value.
Object.defineProperty(a, 1, {value:7, enumerable: true, configurable: true, writable: true});
assertEq(JSON.stringify(Object.getOwnPropertyDescriptor(a, 1)),
`{"value":7,"writable":true,"enumerable":true,"configurable":true}`);
// Can make non-writable, non-configurable, non-enumerable.
Object.defineProperty(a, 1, {value:9, enumerable: true, configurable: true, writable: false});
assertEq(JSON.stringify(Object.getOwnPropertyDescriptor(a, 1)),
`{"value":9,"writable":false,"enumerable":true,"configurable":true}`);
Object.defineProperty(a, 0, {value:4, enumerable: true, configurable: false, writable: true});
assertEq(JSON.stringify(Object.getOwnPropertyDescriptor(a, 0)),
`{"value":4,"writable":true,"enumerable":true,"configurable":false}`);
Object.defineProperty(a, 2, {value:3, enumerable: false, configurable: true, writable: true});
assertEq(JSON.stringify(Object.getOwnPropertyDescriptor(a, 2)),
`{"value":3,"writable":true,"enumerable":false,"configurable":true}`);
// Turn into an accessor.
Object.defineProperty(a, 4, {get:() => -2, enumerable: true, configurable: true});
// Can't add new properties.
assertThrowsInstanceOf(() => Object.defineProperty(a, 3,
{value:4, enumerable: true,
configurable: true,
writable: true}),
TypeError);
assertThrowsInstanceOf(() => Object.defineProperty(a, 10,
{value:4,
enumerable: true,
configurable: true,
writable: true}),
TypeError);
assertEq(a.toString(), "4,9,3,,-2");
}
for (var i = 0; i < 15; i++)
testNonExtensible();
function testSealed() {
var a = [1, 2, 3, , 5];
Object.seal(a);
// Can change the value.
Object.defineProperty(a, 1, {value:7, enumerable: true, configurable: false, writable: true});
assertEq(JSON.stringify(Object.getOwnPropertyDescriptor(a, 1)),
`{"value":7,"writable":true,"enumerable":true,"configurable":false}`);
// Can make non-writable.
Object.defineProperty(a, 0, {value:4, enumerable: true, configurable: false, writable: false});
// Can't make configurable, non-enumerable.
assertThrowsInstanceOf(() => Object.defineProperty(a, 2,
{value:7,
enumerable: true,
configurable: true,
writable: true}),
TypeError);
assertThrowsInstanceOf(() => Object.defineProperty(a, 2,
{value:7,
enumerable: false,
configurable: false,
writable: true}),
TypeError);
// Can't turn into an accessor.
assertThrowsInstanceOf(() => Object.defineProperty(a, 4, {get:() => -2,
enumerable: true,
configurable: true}),
TypeError);
// Can't add new properties.
assertThrowsInstanceOf(() => Object.defineProperty(a, 3,
{value:4, enumerable: true,
configurable: true,
writable: true}),
TypeError);
assertThrowsInstanceOf(() => Object.defineProperty(a, 10,
{value:4,
enumerable: true,
configurable: true,
writable: true}),
TypeError);
assertEq(a.toString(), "4,7,3,,5");
}
for (var i = 0; i < 15; i++)
testSealed();
function testFrozen() {
var a = [1, 2, 3, , 5];
Object.freeze(a);
// Can redefine with same value/attributes.
Object.defineProperty(a, 0, {value:1, enumerable: true, configurable: false, writable: false});
// Can't change the value.
assertThrowsInstanceOf(() => Object.defineProperty(a, 1,
{value:7,
enumerable: true,
configurable: false,
writable: false}),
TypeError);
// Can't make configurable, non-enumerable.
assertThrowsInstanceOf(() => Object.defineProperty(a, 2,
{value:3,
enumerable: true,
configurable: true,
writable: false}),
TypeError);
assertThrowsInstanceOf(() => Object.defineProperty(a, 2,
{value:3,
enumerable: false,
configurable: false,
writable: false}),
TypeError);
// Can't turn into an accessor.
assertThrowsInstanceOf(() => Object.defineProperty(a, 4, {get:() => -2,
enumerable: true,
configurable: true}),
TypeError);
// Can't add new properties.
assertThrowsInstanceOf(() => Object.defineProperty(a, 3,
{value:4, enumerable: true,
configurable: true,
writable: true}),
TypeError);
assertThrowsInstanceOf(() => Object.defineProperty(a, 10,
{value:4,
enumerable: true,
configurable: true,
writable: true}),
TypeError);
assertEq(a.toString(), "1,2,3,,5");
}
for (var i = 0; i < 15; i++)
testFrozen();