212887 2020-06-07 20:14:54 -0700 Invalid escape sequence with a non-octal-eight 2020-06-08 14:21:18 -0700 1 1 1 Unclassified WebKit JavaScriptCore Other PC Linux RESOLVED MOVED P2 Normal --- 1 junior.jefferson webkit-unassigned ross.kirsling oldest_to_newest 1660118 0 junior.jefferson 2020-06-07 20:14:54 -0700 Hi everyone, maybe is a case of an invalid numeric escape (non-octal-eight) in strict mode, but the same occurs using the strict mode and without it. Is this an expected behavior of JavaScriptCore? (implementation-dependent) version: 262693 OS: Linux Ubuntu 19.10 x64 Steps to reproduce: print(`\8`); Actual results: SyntaxError: untagged template literal contains invalid escape sequence Expected results: 8 The same occurs in strict mode "use strict"; print(`\8`); V8, SpiderMonkey, Chakra works as expected. cinfuzz 1660354 1 ross.kirsling 2020-06-08 13:39:59 -0700 Based on the spec: https://tc39.es/ecma262/#sec-literals-string-literals https://tc39.es/ecma262/#sec-additional-syntax-string-literals https://tc39.es/ecma262/#sec-template-literal-lexical-components https://tc39.es/ecma262/#sec-static-semantics-template-early-errors It would appear that our behavior is correct -- namely, it's only non-template strings that should support numeric escapes other than '\0'. If so, then the thing to do here would be to add test262 cases for the other engines to fix. 1660357 2 ross.kirsling 2020-06-08 13:40:45 -0700 (In reply to Ross Kirsling from comment #1) > It would appear that our behavior is correct -- namely, it's only > non-template strings that should support numeric escapes other than '\0'. Oops, I ended my sentence too early. Should be "... in sloppy mode." 1660386 3 ross.kirsling 2020-06-08 14:21:18 -0700 Closing here but opened https://github.com/tc39/test262/issues/2653 for the remaining work.