ES6 Katas Level 3 - Tagged Template Strings

Question

I am trying to learn ES6 by solving ES6 Katas.

However, I am stuck at the following line starting with it('expressions are NOT passed to it'...). I am not allowed to change the assert line. I couldn't find a way to concat "two" to the returned strings array.

It might be a really simple question, but I would appreciate any help.

Thanks in advance.

describe('the 1st parameter - receives only the pure strings of the template string', function() {

  function tagFunction(strings) {
    return strings;
  }

  it('the strings are an array', function() {
    var result = ['template string'];
    assert.deepEqual(tagFunction`template string`, result);
  });

  it('expressions are NOT passed to it', function() {
    var tagged = tagFunction`one`;
    assert.deepEqual(tagged, ['one', 'two']);
  });

});