HORIZON PROJECT

var escapeHtmlChar = require('./_escapeHtmlChar'),

    toString = require('./toString');

/** Used to match HTML entities and HTML characters. */

var reUnescapedHtml = /[&<>"']/g,

    reHasUnescapedHtml = RegExp(reUnescapedHtml.source);

/**

 * Converts the characters "&", "<", ">", '"', and "'" in `string` to their

 * corresponding HTML entities.

 *

 * **Note:** No other characters are escaped. To escape additional

 * characters use a third-party library like [_he_](https://mths.be/he).

 *

 * Though the ">" character is escaped for symmetry, characters like

 * ">" and "/" don't need escaping in HTML and have no special meaning

 * unless they're part of a tag or unquoted attribute value. See

 * [Mathias Bynens's article](https://mathiasbynens.be/notes/ambiguous-ampersands)

 * (under "semi-related fun fact") for more details.

 *

 * When working with HTML you should always

 * [quote attribute values](http://wonko.com/post/html-escaping) to reduce

 * XSS vectors.

 *

 * @static

 * @since 0.1.0

 * @memberOf _

 * @category String

 * @param {string} [string=''] The string to escape.

 * @returns {string} Returns the escaped string.

 * @example

 *

 * _.escape('fred, barney, & pebbles');

 * // => 'fred, barney, & pebbles'

 */

function escape(string) {

  string = toString(string);

  return (string && reHasUnescapedHtml.test(string))

    ? string.replace(reUnescapedHtml, escapeHtmlChar)

    : string;

}

module.exports = escape;