iOS Unit Testing by Example

Make a Place to Play

You know the drill. Create a new project by following the steps for ​Create a Place to Play with Tests​, but give it the name TextField. Delete its initial test file.

Let’s use the predefined storyboard-based view controller. Edit ViewController.swift, adding two text field outlets. We’ll use them to enter the username and password for a simple login simulation. Declare these outlets private(set) so that our tests can reach them:

TextField/TextField/ViewController.swift

@IBOutlet private(set) var usernameField: UITextField!
@IBOutlet private(set) var passwordField: UITextField!

We need something to serve as the delegate for the text fields. Let’s follow the common practice of using the view controller. ...