Running tests
Xcode provides many different ways to execute tests. You have already seen two ways to execute all the tests in the test suite: go to the Project | Test menu item or use the ⌘U keyboard shortcut.
Running one specific test
In TDD, you normally want to run all the tests as often as possible. Running the tests gives you confidence that the code does what you intended when you wrote the tests. In addition to this, you want immediate feedback (that is, a failing test) whenever new code breaks a seemingly unrelated feature. Immediate feedback means that your memory of the changes that broke the feature is fresh, and the fix is made quickly.
Nevertheless, sometimes, you need to run one specific test, but don't let it become a habit. To run one specific test, you can click on the diamond visible next to the test method:
Figure 3.6 – Run one specific test by clicking the diamond next to the test method in the gutter
When you...
