In this talk, you will learn: - how to take advantage of Mockito and other libraries to write good JVM and Espresso tests - how to use DaggerMock (an open source library available on github https://github.com/fabioCollini/DaggerMock) to avoid boilerplate code in tests - how to test asynchronous RxJava code using a JVM test Writing reliable tests is not easy for many reasons, especially when asynchronous code is involved. Some libraries can be used to create a testable architecture (for example Dagger and RxJava) and to simplify testing (Mockito, AssertJ and DaggerMock). In this talk we’ll see how to write JVM and Espresso tests with particular attention on how to replace real objects with mocks and how to test asynchronous RxJava code.