Implementing the ItemManager class

The to-do app will show all the to-do items in a list. The list of items will be managed by a class called ItemManager. It will expose an interface to get, add, and remove items.

Open Project Navigator and select the ToDoTests group. Go to iOS | Source | Unit Test Case Class to create a test case class with the name, ItemManagerTests, and put it in the Model folder. Import the ToDo module (@testable import ToDo) and remove the two test method templates.

Count

The requirements from Chapter 2, Planning and Structuring Your Test-Driven iOS App, ask for a list with unchecked to-do items at the top and checked to-do items at the bottom of the list in the app. How the items are presented is not a matter of concern with regard to the model. But it has to be possible to get the number of unchecked and checked to-do items from the item manager.

Add the following code to ItemManagerTests:

func testToDoCount_Initially_ShouldBeZero() {
    let sut = ItemManager()
}

The...