1109577 - Accessing `RegExp.prototype.flags` directly should throw

Status: RESOLVED INVALID

(Core :: JavaScript: Standard Library, defect)

Description

[Mathias Bynens]

Since bug 1108467 the following test was added to the codebase:

    assertEq(RegExp.prototype.flags, "");

However, `RegExp.prototype.flags` should throw since it accesses `RegExp.prototype.global` which throws in step 3 of its algorithm (since `R = RegExp.prototype` in this situation):

    3. If R does not have an [[OriginalFlags]] internal slot throw a TypeError exception.

Consider removing this broken test and behavior.

Comment 1

[ziyunfei]

Oh, indeed!

Comment 2

[Mathias Bynens]

Since none of the major ECMAScript engines seem to implement the part of the algorithm described above, maybe the spec should be changed. I’ve filed https://bugs.ecmascript.org/show_bug.cgi?id=3432.

Comment 3

[Claude Pache]

A recent amendment of the spec (https://github.com/tc39/ecma262/pull/511) made this bug invalid: now RegExp.prototype.flags should produce "".

Comment 4

[Tom S. (please needinfo tschuster)]

Claude is right.