Which Tests Should I Write?

So, which should we use? Instrumented tests? Unit tests? Both?

If you only wanted to worry about one, choose instrumented tests. Everything can be tested using instrumented tests, while unit tests cannot readily test everything.

For larger projects — particularly those where tests will be run frequently — the speed gain from unit tests can be significant. So, a typical philosophy is:

• Test what you can with unit tests
• Test the other stuff with instrumented tests

We will return to this question later in the chapter, after exploring the various testing options at our disposal.