1var escapeHtmlChar = require('./_escapeHtmlChar'),
2    toString = require('./toString');
3
4/** Used to match HTML entities and HTML characters. */
5var reUnescapedHtml = /[&<>"']/g,
6    reHasUnescapedHtml = RegExp(reUnescapedHtml.source);
7
8/**
9 * Converts the characters "&", "<", ">", '"', and "'" in `string` to their
10 * corresponding HTML entities.
11 *
12 * **Note:** No other characters are escaped. To escape additional
13 * characters use a third-party library like [_he_](https://mths.be/he).
14 *
15 * Though the ">" character is escaped for symmetry, characters like
16 * ">" and "/" don't need escaping in HTML and have no special meaning
17 * unless they're part of a tag or unquoted attribute value. See
18 * [Mathias Bynens's article](https://mathiasbynens.be/notes/ambiguous-ampersands)
19 * (under "semi-related fun fact") for more details.
20 *
21 * When working with HTML you should always
22 * [quote attribute values](http://wonko.com/post/html-escaping) to reduce
23 * XSS vectors.
24 *
25 * @static
26 * @since 0.1.0
27 * @memberOf _
28 * @category String
29 * @param {string} [string=''] The string to escape.
30 * @returns {string} Returns the escaped string.
31 * @example
32 *
33 * _.escape('fred, barney, & pebbles');
34 * // => 'fred, barney, &amp; pebbles'
35 */
36function escape(string) {
37  string = toString(string);
38  return (string && reHasUnescapedHtml.test(string))
39    ? string.replace(reUnescapedHtml, escapeHtmlChar)
40    : string;
41}
42
43module.exports = escape;
44