Bug 138563 – The third parameter of a Map.prototype.forEach callback function is undefined

• Component: JavaScriptCore
• Status: RESOLVED FIXED

[Steve South]

Codepen here:

http://codepen.io/stevesouth/pen/NPKzYz/

According to MDN the callback function of a Map.forEach should get called with three arguments

callback is invoked with three arguments:

    the element value
    the element key
    the Map object being traversed

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map/forEach

However in Webkit the third parameter is undefined.

[Radar WebKit Bug Importer]

<rdar://problem/18943661>

[Diego Pino]

Created attachment 242741 [details]
Patch

[Diego Pino]

The same change is necessary for Set. According to the ES6 spec [1]:

"callbackfn is called with three arguments: the first two arguments are a value contained in the Set. The same value of passed for both arguments. The Set object being traversed is passed as the third argument."

[1] http://people.mozilla.org/~jorendorff/es6-draft.html#sec-set.prototype.foreach

[Matthew Mirman]

Comment on attachment 242741 [details]
Patch

The map part was updated in http://trac.webkit.org/changeset/183374

[Matthew Mirman]

And the set part in https://bugs.webkit.org/show_bug.cgi?id=144188

[Geoffrey Garen]

Comment on attachment 242741 [details]
Patch

r=me