on 3.1.1-10 AFAIK `Object.preventExtension({})` makes __proto__ immutable.
Since `Object.freeze({})` includes that `preventExtension` call, immutable
should be so no `y` inherited there.On Thu, Jul 4, 2013 at 3:10 PM, David Bruant <[email protected]> wrote: > Hi, > > So, there are standard tests now for ES6! > http://samples.msdn.microsoft.**com/ietestcenter/#javascript<http://samples.msdn.microsoft.com/ietestcenter/#javascript> > > I'd like to discuss some of the __proto__ tests at > http://samples.msdn.microsoft.**com/ietestcenter/Javascript/** > testcases__proto_.html<http://samples.msdn.microsoft.com/ietestcenter/Javascript/testcases__proto_.html> > > > # 3.1.1-10 Object.freeze(Object.**prototype) disables __proto__ > > function testcase() { > Object.freeze(Object.**prototype); > var a = new Object(); > a.__proto__ = { y: 2 }; > return a.y === undefined; > } > > I'm not sure I see why this test should succeed. Freezing "a" should > prevent its [[Prototype]] from being changed, but I don't see why it would > be the case for Object.prototype. > > (same for 3.1.1-9 for Object.seal) > > > # 3.1.1-11 [[DefineOwnProperty]] UnderScoreProtoEnabled is set to true > when Object.prototype is set with default values > > function testcase() { > Object.defineProperty(Object.**prototype, "__proto__", { writable: > true, enumerable: false, configurable: true }); > > var obj = {}; > obj.__proto__ = { x: 10 }; > return obj.x === 10; > } > > I don't fully understand this test case. I think that overriding > Object.prototype.__proto__ with a data attribute should remove its magic. > > (same for 3.1.1-7, 3.1.2-4-1+bcd ) > > > # 3.1.1-4 Object.prototype.__proto__ is data property with > {writable:true, enumerable:false, configurable:true, value:null} attributes > > function testcase() { > var desc = Object.**getOwnPropertyDescriptor(**Object.prototype, > "__proto__"); > return desc.writable === true && > desc.enumerable === false && > desc.configurable === true && > desc.value === null; > } > > ... hmm... I admire the sense of humor of whoever wrote that test. > TC39 Meeting notes from May 2013: > https://github.com/rwldrn/**tc39-notes/blob/master/es6/** > 2013-05/may-21.md#**consensusresolution-5<https://github.com/rwldrn/tc39-notes/blob/master/es6/2013-05/may-21.md#consensusresolution-5>: > >> __proto__ is an accessor on Object.prototype. >> > > > > # 3.1.1-6 Modification of Object.prototype.__proto__ causes > UnderScoreEnabled to be set to false. Setting it to {} > > function testcase() { > Object.defineProperty(Object.**prototype, "__proto__", {}); > > var obj = new Object(); > obj.__proto__ = { y: 2 }; > return obj.y === undefined; > > } > > I believe the Object.defineProperty line is a no-op, so the test should > fail. > > > # 3.1.2-2-14b [[Put]] __proto__ with value {y:2} on window object > > function testcase() { > window.__proto__ = { y: 2 }; > return window.y === undefined; > } > > window is not part of ECMAScript. This test might as well throw a > ReferenceError. > As far as the global object, I don't think it's status on [[Prototype]] is > very clear from a standard standpoint, so I would recommend not having > tests for that. > > > I only looked at the tests failing in Firefox, there are probably other > errors. > It would be good if the tests were reviewed carefully *before* becoming > part of any sort of "conformance" test suite. > > David > ______________________________**_________________ > es-discuss mailing list > [email protected] > https://mail.mozilla.org/**listinfo/es-discuss<https://mail.mozilla.org/listinfo/es-discuss> >
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