index.js

'use strict';

module.exports = string => {
	if (typeof string !== 'string') {
		throw new TypeError('Expected a string');
	}

	// Escape characters with special meaning either inside or outside character sets.
	// 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.
	return string
		.replace(/[|\\{}()[\]^$+*?.]/g, '\\$&')
		.replace(/-/g, '\\x2d');
};