The Java testing framework is the backbone of Android testing, and sometimes, you can get away without writing Android-specific code. This can be a good thing, because as we continue on our testing quest, you will notice that we deploy Android framework tests to a device, and this has an impact on the speed of our tests, that is, the speed we get feedback from a pass or a fail.

If you architect your app in a clever way, you can create pure Java classes that can be tested in isolation away from Android. The two main benefits of this are increased speed of feedback from test results, and also, to quickly plug together libraries and code snippets to create powerful test suites, you can use the near ten years of experience of other programmers doing Java testing.