Bug 205783 – RegExp.prototype[Symbol.replace] does not support named capture groups

• Status: RESOLVED
• Resolution: FIXED
• Component: JavaScriptCore

[Alexey Shvayka]

While String.prototype.replace() works as expected with named capture groups, slow path is not implemented.

Test case:
  /(?<a>.)/[Symbol.replace]("b", "$<a>")

Expected:
  "b"

Actual:
  "$<a>"

ECMA262:
  https://tc39.es/ecma262/#sec-regexp.prototype-@@replace (step 14.j)

Test262:
  https://test262.report/browse/built-ins/RegExp/named-groups/groups-object-subclass-sans.js
  https://test262.report/browse/built-ins/RegExp/named-groups/groups-object-subclass.js

[Alexey Shvayka]

Created attachment 386803 [details]
Patch

[Ross Kirsling]

Comment on attachment 386803 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=386803&action=review

r=me with nits

> Source/JavaScriptCore/ChangeLog:10
> +        (step 14.j of https://tc39.es/ecma262/#sec-regexp.prototype-@@replace)

Probably better to indicate that it's not just 14.j but 14.j-l.

> Source/JavaScriptCore/builtins/RegExpPrototype.js:360
> +                namedCaptures = @toObject(namedCaptures, "RegExp.prototype[Symbol.replace] requires result.group not be null or undefined");

Hmm, this is meant to be `result.groups`, right?  Though that still seems a bit problematic since `result` is an internal name. And I guess we've verified that it's not undefined.

How about this?
"RegExp.prototype.@@replace does not allow matches to have a null 'groups' property."

[Alexey Shvayka]

Created attachment 387020 [details]
Patch

Set reviewer, tweak ChangeLog and error message.

[Alexey Shvayka]

(In reply to Ross Kirsling from comment #2)
> How about this?
> "RegExp.prototype.@@replace does not allow matches to have a null 'groups'
> property."

Thank you for review, I went with "RegExp.prototype[Symbol.replace] requires 'groups' property of a match not be null" to avoid @@ notation (because of https://github.com/tc39/ecma262/pull/1314) and for consistency with other @toObject error messages.

[Ross Kirsling]

Guess there's a rebase conflict here.

[Alexey Shvayka]

Created attachment 387075 [details]
Patch

Rebase patch.

[WebKit Commit Bot]

Comment on attachment 387075 [details]
Patch

Clearing flags on attachment: 387075

Committed r254195: <https://trac.webkit.org/changeset/254195>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.

[Radar WebKit Bug Importer]

<rdar://problem/58406622>