3 module.exports = string => {
4 if (typeof string !== 'string') {
5 throw new TypeError('Expected a string');
8 // Escape characters with special meaning either inside or outside character sets.
9 // Use a simple backslash escape when it’s always valid, and a \unnnn escape when the simpler form would be disallowed by Unicode patterns’ stricter grammar.
11 .replace(/[|\\{}()[\]^$+*?.]/g, '\\$&')
12 .replace(/-/g, '\\x2d');