code: function assertStd (result, std) {
      var message = 'Expected value to match following regexp: ' + std + ', but got: ' + result;
  
      if (typeof std === 'string' || typeof std === 'number') {
        assert.equal(result && result.code || result, std);
      }
      else if (std instanceof RegExp) {
        assert.isNotNull(result.match(std), message);
      }
      else if (typeof std === 'function') {
        assert.ok(std(result));
      }
      else if (typeof result !== 'string' && result !== null) {
        assert.equal(result.code, 0);
      }
    }
docs: In case std is:  * String - Check if result is equal to std * RegExp - Check if result.match(std) != null * Function - call it and assert that return value will be true * Other - Check if result is empty