public void AddLinesToListBoxTest() { //arrange ListBox box = new ListBox(); Display display = new Display(); RepeatedLine line1 = new RepeatedLine(3, "This is some content", new List <string> { "file1", "file2", "file3" }); RepeatedLine line2 = new RepeatedLine(8, "This is some more content", new List <string> { "file2", "file3" }); //act display.AddLinesToListBox(box, new List <RepeatedLine> { line1, line2 }); List <RepeatedLine> actual = (List <RepeatedLine>)box.DataSource; List <RepeatedLine> expected = new List <RepeatedLine> { line2, line1 }; //assert Assert.IsTrue(actual.SequenceEqual(expected)); }