public void Should_Add_Elements_To_Array() { var arrayOfInts = new int[] { 1, 2, 3, 4, 5 }; var arrayToBeAdded = new int[] { 6, 7, 8 }; var arrayOfIntsWithAdd = arrayOfInts.AddElements(arrayToBeAdded); foreach (var i in arrayOfIntsWithAdd) { Assert.Contains(i, arrayOfIntsWithAdd); } }