200638 2019-08-12 11:50:36 -0700 jsc errors on unicode escapes in keywords in non-keyword positions 2020-12-06 07:38:22 -0800 1 1 1 Unclassified WebKit JavaScriptCore Other Unspecified Windows 10 RESOLVED DUPLICATE 219575 InRadar P2 Normal --- 1 wwigham webkit-unassigned ashvayka fpizlo keith_miller mark.lam webkit-bug-importer ysuzuki oldest_to_newest 1560497 0 wwigham 2019-08-12 11:50:36 -0700 Steps to reproduce the problem: 1. Paste `const a = {def\u0061ult: 12}` into interpreter What is the expected behavior? No errors, `a` is an object with a member named `default` with value `12`. What went wrong? `Uncaught SyntaxError: Keyword must not contain escaped characters` Relevant spec section: https://tc39.es/ecma262/#prod-IdentifierName This works in chakra-based edge and firefox, however chrome exhibits the same [bug](https://bugs.chromium.org/p/chromium/issues/detail?id=993000&can=2&q=unicode%20escape). I happened to find this while working on https://github.com/microsoft/TypeScript/pull/32718. 1560498 1 wwigham 2019-08-12 11:51:56 -0700 Apologies, the error in JSC isn't the one listed above, but rather `SyntaxError: Unexpected escaped characters in keyword token: 'def\u0061ult'`. 1560607 2 wwigham 2019-08-12 16:56:21 -0700 Relevant test262 issue, since there doesn't seem to be a test covering it yet: https://github.com/tc39/test262/issues/2285 1560988 3 webkit-bug-importer 2019-08-13 15:36:21 -0700 <rdar://problem/54277270> 1712320 4 ashvayka 2020-12-06 07:38:22 -0800 (In reply to Wesley Wigham from comment #2) > Relevant test262 issue, since there doesn't seem to be a test covering it > yet: https://github.com/tc39/test262/issues/2285 Thank you Wesley for discovering this and filing the issues. It's so great there so many projects contributing back to test262! Yusuke fixed this in r270481. *** This bug has been marked as a duplicate of bug 219575 ***