quick-lint-js

Find bugs in JavaScript programs.

E0207: code point in Unicode escape sequence must not be greater than U+10FFFF

Identifiers, string literals, and template literals can contain Unicode escape sequences starting with \u. It is a syntax error for a Unicode escape sequence to refer to a character which is beyond the range of valid Unicode code points (U+0000 to U+10FFFF):

class ChirpSound {}
let bird\u{360000} = new ChirpSound();

let x = "hello\u{abcdef}";

To fix this error, make sure that the escaped code point is between U+0000 and U+10FFFF inclusive.

class ChirpSound {}
let bird\u{3600} = new ChirpSound();

let x = "hello\u{abcde}";

Documentation for other errors