Diff Two Array code not working on FCC

**Code is running fine in google chrome but not passing test cases on free code camp, and no error is displayed **

Your code so far

  var items = [];
  var newArr = arr1.concat(arr2);
  items = newArr.filter(function(doge){
    return !arr1.includes(doge) || !arr2.includes(doge);
  });
}

// test here
diffArray([1, 2, 3, 5], [1, 2, 3, 4, 5]);

Your browser information:

Your Browser User Agent is: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/61.0.3163.100 Safari/537.36.

Link to the challenge:
https://www.freecodecamp.org/challenges/diff-two-arrays

Silly mistake i was not returning items array after filtering it