is-textcontent-of-script.js : script要素の内容が正しいかを検査する(HTML5準拠)

is-textcontent-of-script.js

/**
 * is-textcontent-of-script.js
 *
 * @version 1.0.1
 * @author think49
 * @see <a href="http://www.whatwg.org/specs/web-apps/current-work/multipage/scripting-1.html#restrictions-for-contents-of-script-elements">4.3.1.2 Restrictions for contents of script elements - HTML5 Standard</a>
 */

'use strict';

function isTextcontentOfScript (textContent) {
  var script, escape, data1, not_data1, data2, not_data2, data3, not_data3, script_start, script_end, lt, slash, s, c, r, i, p, t, tag_end;

  lt = '\x3C';
  slash = '/';

  s = '[Ss]';
  c = '[Cc]';
  r = '[Rr]';
  i = '[Ii]';
  p = '[Pp]';
  t = '[Tt]';

  tag_end = '[\x09\x0A\x0C\x20\x2F\x3E]';

  script_start = lt + s + c + r + i + p + t + tag_end;
  script_end = lt + slash + s + c + r + i + p + t + tag_end;

  not_data1 = '\x3C--';
  data1 = '(?:(?!' + not_data1 + ')[\\s\\S])*';

  not_data2 = '(?:' + script_start + '|--\x3E)';
  data2 = '(?:(?!' + not_data2 + ')[\\s\\S])*';

  not_data3 = '(?:' + script_end + '|--\x3E)';
  data3 = '(?:(?!' + not_data3 + ')[\\s\\S])*';

  escape = '\x3C--' + data2 + '(?:' + script_start + data3 + script_end + data2 + ')*';

  script = data1 + '(?:' + escape + '(?:' + script_start + data3 + ')?--\x3E' + data1 + ')*(?:' + escape + ')?';

  return new RegExp('^' + script + '$').test(textContent);
}

参考リンク。

• 4.3.1.2 Restrictions for contents of script elements - HTML 5 Standard