string/escapeRegExp.js

define(['../internal/baseToString'], function(baseToString) {

  /**
   * Used to match `RegExp` special characters.
   * See this [article on `RegExp` characters](http://www.regular-expressions.info/characters.html#special)
   * for more details.
   */
  var reRegExpChars = /[.*+?^${}()|[\]\/\\]/g,
      reHasRegExpChars = RegExp(reRegExpChars.source);

  /**
   * Escapes the `RegExp` special characters "\", "^", "$", ".", "|", "?", "*",
   * "+", "(", ")", "[", "]", "{" and "}" in `string`.
   *
   * @static
   * @memberOf _
   * @category String
   * @param {string} [string=''] The string to escape.
   * @returns {string} Returns the escaped string.
   * @example
   *
   * _.escapeRegExp('[lodash](https://lodash.com/)');
   * // => '\[lodash\]\(https://lodash\.com/\)'
   */
  function escapeRegExp(string) {
    string = baseToString(string);
    return (string && reHasRegExpChars.test(string))
      ? string.replace(reRegExpChars, '\\$&')
      : string;
  }

  return escapeRegExp;
});