Document inability to match lone low surrogates accurately #17
Description
var regex = /^a[\u{D800}-\u{DBFF}\u{DC00}-\u{DFFF}]b$/u;
console.log(
regex.test('a\uD800b'),
regex.test('a\uDC00b')
);Expected: true, true
Actual: true, false
Ref. mathiasbynens/regenerate#28 (comment).
https://esdiscuss.org/topic/q-lonely-surrogates-and-unicode-regexps#content-3