public void ItShouldFilterTasks() { TaskList testList = new TaskList(); Task testTask1 = new Task(); testTask1.TaskDescription = "First task"; Task testTask2 = new Task(); testTask2.TaskDescription = "Second"; Task testTask3 = new Task(); testTask3.TaskDescription = "Third task"; testList.AddTask(ref testTask1); testList.AddTask(ref testTask2); testList.AddTask(ref testTask3); List<Task> filteredList = testList.FilterTasks("task"); var actual = filteredList; var expected = new List<Task>(); expected.Add(testTask1); expected.Add(testTask3); CollectionAssert.AreEqual(expected, actual); }