ClassCastException exception when running Robolectric test with Power Mock on multiple files

Question

So I set up the power mock based on the reference guide here. It all seems to run perfectly fine with a single test class. But when executing multiple JUnit tests I am getti

Answer 1

I would suggest to disable ClassCache of Mockito as suggested in the exception message . Here is how I disable Mockito ClassCache by adding a MockitoConfiguration class in Android Studio.

1. Under your unit test directory, src/test/java, create a package directory that is exactly the same as Mockito configuration package, org/mockito/configuration.

2. So under the full test directory src/test/java/org/mockito/configuration, add a new class named MockitoConfiguration.

3. Overwrite the enableClassCache() method as following.

   package org.mockito.configuration;
   
       public class MockitoConfiguration extends DefaultMockitoConfiguration {
   
       @Override
       public boolean enableClassCache() {
           return false;
       }
   }
   

4. When you run your Unit test under src/java/test, your MockitoConfiguration should be loaded and Mockito class cache should be disabled.

Hope it helps.

Answer 2

So I solved this problem by adding

@PowerMockIgnore({ "*.*" }) 
@PrepareForTest({ StaticClass1.class,StaticClass2.class })

That will make Power mock ignore all the classes. For my case PowerMock was classloading the Bus which in my code was actually mocked by Mockito.Once I added the annotations above all the classes in the testsuite worked without any errors.