iOS Unit Testing by Example

Test the Submit Button

The behavior of the Submit button is defined in the changePassword method. This is a big one. The method has 116 lines with three sections. The first section checks the inputs. The second sets up the appearance of the view while we wait for the password call to finish. The third section passes the inputs to the password changer and handles success or failure. Let’s test this, step by step.

Since our tests will be tapping the Submit button, let’s add a helper to TestHelpers.swift to make these tests more expressive:

Refactoring/RefactoringTests/TestHelpers.swift

func tap(_ button: UIButton) {
    button.sendActions(for: .touchUpInside)
}

The Submit button interacts with the password changer. We created a MockPasswordChanger ...