phpjs/experimental/misc/php_check_syntax.js

php.js offers community built php functions in javascript

function php_check_syntax(filename, error_message) {
  // http://kevin.vanzonneveld.net
  // +   original by: Brett Zamir (http://brett-zamir.me)
  // -    depends on: ob_start
  // -    depends on: file_get_contents
  // -    depends on: ob_end_clean
  // %          note 1: Relies on eval(), so use, if at all, with caution
  // %          note 2: error_message, if used, must be a string referring to a global variable name
  // *     example 1: var myErr = '';
  // *     example 1: php_check_syntax('http://kevin.vanzonneveld.net/pj_test_supportfile_1.htm', 'myErr');
  // *     returns 1: false

  // Should not output contents, but will evaluate, as per PHP
  this.ob_start();
  try {
    eval(file_get_contents(filename));
  }
  catch (e) {
    if (error_message) {
      this.window[error_message] = e.message;
    }
    return false;
  }
  this.ob_end_clean();
  return true;
}