Not intentional. I forgot that getDate was Annex B.
On Wed, Jan 21, 2015 at 6:01 PM, Allen Wirfs-Brock <[email protected]> wrote: > > On Jan 21, 2015, at 2:09 PM, Mark S. Miller wrote: > > // old ES5 code > > function f(allegedDate) { > if (({}).toString.call(allegedDate) === "[object Date]") { > JSON.stringify(allegedDate); // "[]" impossible in ES5 > Array.isArray(allegedDate); // true impossible in ES5 > Date.prototype.getYear.call(allegedDate); // error impossible in ES5 > } > } > > > // new ES6 code > > const fakeDate = []; > const defProp = Object.defineProperty; > defProp(fakeDate, Symbol.toStringTag, { value: "[object Date]" }); > f(fakeDate); // all ES5 impossible behaviors happen > > > not quite. The last of your tests (getYear) will still fail because > fakeDate is not internally branded as a date. > > See > http://people.mozilla.org/~jorendorff/es6-draft.html#sec-date.prototype.getyear > step > 1 and the definition of "this time value" in > http://people.mozilla.org/~jorendorff/es6-draft.html#sec-properties-of-the-date-prototype-object > > > (BTW, did you intentionally pick an Annex B Date method?) > > Allen > -- Cheers, --MarkM
_______________________________________________ es-discuss mailing list [email protected] https://mail.mozilla.org/listinfo/es-discuss
