Escape a regular expression in JavaScript

Regular expressions are a powerful tool for pattern matching and string manipulation. However, when you need to use a string as a regular expression, you need to escape special characters to avoid syntax errors.

Luckily, escaping a string for use in a regular expression is not hard, but it requires, you guessed it, a regular expression! By using the String.prototype.replace() method, you can escape special characters in a string.

The regular expression that you can then use to escape special characters is /[.*+?^${}()|[\]\\]/g. This regular expression matches all the special characters used in regular expressions. Then, each match is replaced with the escaped version of the character using \\$&.

const escapeRegExp = str => str.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');

escapeRegExp('(test)'); // \\(test\\)