Bug 212887 – Invalid escape sequence with a non-octal-eight

• Status: RESOLVED
• Resolution: MOVED
• Component: JavaScriptCore

[Jefferson Junior]

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

[Ross Kirsling]

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.

[Ross Kirsling]

(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."

[Ross Kirsling]

Closing here but opened https://github.com/tc39/test262/issues/2653 for the remaining work.