Test Driven Development For Android

Question

Can we use JUnit for test driven development in Android ? If not, is there an alternative similar to JUnit ?

I searched a bit on google and also read a SO post Android Test Driven Development It looks like Android was never made with TDD in mind. I wanted to be sure before I begin learning TDD and doing Android development at the same time.

Answer 1

Yeah we can use JUnit for test driven development. To initiate with you can refer to following link : http://developer.android.com/tools/testing/testing_android.html#JUnit Following the documentation we can use the junit.framework to have unit testing done.

Answer 2

I think you can completely rely on Robolectric for running your tests in JVM. You get to use JUnit4 for testing your POJOs and Robolectric provides you the support for testing the Android components.

I am also a beginner in TDD for Android Development. I find Robolectric really useful for test driving my code.

This video will tell you almost everything it provides you for unit testing the Android code.

UPDATE: With the Android studio support and the new Android ecosystem, now unit testing can be done as a first class practice. Refer http://developer.android.com/training/testing/unit-testing/local-unit-tests.html for more details.

There are couple of good approaches to test drive the android code. The most effective ones I have found so far is using MVVM(model-view-viewmodel) or MVP(model-view-presenter) approach, where the business logic as well as presentation logic is decoupled from the view and can be easily be unit tested.

Answer 3

Here is a bit of explanation of the problem space: http://www.techwell.com/2013/04/applying-test-driven-development-android-development

The conclusion is you should use Robolectric. Unfortunately Robolectric is slow, and if you follow TDD even on a pragmatic level, you will end up with a couple of hundreds of test, that will run for couple of 10 seconds. And that is not you want to do with TDD. TDD test package should run at most in seconds.

My advise is:

• Create wrapper classes around Android classes that simply call the Android class.
• Write your app logic in pure Java.
• Use Junit (or TestNG or whatever pleases you) to test you model/business logic
• Use occasionally Robolectric for the wrapper classes (probably you won't have to use)
• (You can write integration tests that use multiple classes, Robolectric, etc. but only run it on a separate Continous Integration server eg. hourly)

With this approach your logic will be more portable as well.