1084019 - ES6 "name" property of functions should be configurable

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Boris Zbarsky [:bzbarsky]]

+++ This bug was initially created as a clone of Bug #911142 +++

Just like bug 911142 but for "name".  Simple tests:

  Object.getOwnPropertyDescriptor(Object, "name").configurable
  Object.getOwnPropertyDescriptor(function foo(){}, "name").configurable

Comment 1

[Till Schneidereit [:till]]

Attachment: Make the "name" property of function objects configurable

We had one really short test covering the previous behavior, it seems.

I removed that and added tests covering everything I could think of.

Slightly bungled (wrong commit message, forgot the reportCompare song-and-dance) try-run without web platform tests here:
https://treeherder.mozilla.org/ui/#/jobs?repo=try&revision=b6348b75b5b7

New try run with issues fixed, but containing just the web platform tests:
https://treeherder.mozilla.org/ui/#/jobs?repo=try&revision=3310bb12900e

This builds on top of the similar patch for "length", so should land after or with that.

Comment 2

[Jason Orendorff [:jorendorff]]

Comment on attachment 8536237 [details] [diff] [review]
Make the "name" property of function objects configurable

Review of attachment 8536237 [details] [diff] [review]:
-----------------------------------------------------------------

Cool. Thanks.

::: js/src/jsfun.cpp
@@ +489,5 @@
>      if (isLength || JSID_IS_ATOM(id, cx->names().name)) {
>          MOZ_ASSERT(!IsInternalFunctionObject(obj));
>  
>          RootedValue v(cx);
> +        // Since f.length and f.name are configurable, they could be resolved

Blank line before this comment, please, as required by the style guide (except when the preceding line ends with '{').

::: js/src/tests/ecma_6/Function/function-name.js
@@ +6,5 @@
> +    assertEq(f.name, '');
> +    assertEq(f.hasOwnProperty('name'), false);
> +    f.name = 'g';
> +    assertEq(f.name, '');
> +    Object.defineProperty(f, 'name', {value: 'g'});

Could add one more assertion after this, since it should succeed in defining a new 'name' property.
    assertEq(f.name, 'g');
or something.

Comment 3

[Till Schneidereit [:till]]

Thanks for the review!

remote: https://hg.mozilla.org/integration/mozilla-inbound/rev/be17c68f88cb

Comment 4

[Phil Ringnalda (:philor)]

https://hg.mozilla.org/mozilla-central/rev/be17c68f88cb

Comment 5

[Florian Scholz (Open Web Docs)]

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function/name
https://developer.mozilla.org/en-US/Firefox/Releases/38#JavaScript