A story about trying to get along with Mokit

This is the first post. Do you use "Mockito"?

I used Android Studio for business to create an application, and when I did a Unit Test, I had a fight with Mockito, so I will post it to make friends with Mockito and as my memorandum.

usage environment

macOS Catalina(10.15.6)
Android Studio 4.0.1
Android 9.0(sdk:28)
Mockito Core 3.5.9
Mockito Inline 3.5.9
Robolectric 4.3.1

About the part that quarreled with Mockito

The application I was creating was provided with an interface by aidl and was an application that binds to the service. Initially, I used Robolectric's ShadowApplication.setComponentNameAndServiceForBindService () to pass a Mocked IBinder, but when I retrieve the interface with ʻIBinder.Stub.asInterface ()`, it becomes a different object. I wasn't able to make it into a Mock. (Maybe my Mock was simply wrong.)

It seems that static methods can also be Mocked from Mockito 3.4.0, but I could not find any useful information on the Web, so I will show it below.

How to mock static methods

ʻHow to mock static methods such as IBinder.Stub.asInterface ()`. You can make it a Mock by the following usage.

final IMyService mockMyService = mock(IMyService.class); // ⭐︎1
try(final MockedStatic<IMyService.Stub> mockedStatic = mockStatic(IMyService.Stub.class)) {

// ↓ The return value of IMyService.Stub.asInterface () will be the mocked IMyService (⭐︎1). mockedStatic.when(() -> IMyService.Stub.asInterface(any())).thenReturn(mockMyService); // Please test with bindService () in Activity etc. below. final ActivityController controller = buildActivity(MainActivity.class); controller.create; ... }

By performing the above operation, you can make a static method into a Mock. In the above, it is described as try-with-resources, but if it is not described as try-with-resources, please perform close ().

final MockedStatic<IMyService.Stub> mockedStatic = mockStatic(IMyService.Stub.class);
...
mockedStatic.close();

By the way

You can also Mock a class that is new in a method with Mockito.

final MockedConstruction<SubClass> mockedConstruction = mockConstruction(SubClass.class);

// You can get the new class below // Since the acquired class is Mocked, you can change the return value etc. using when (). List constructed = mockedConstruction.constructed(); mockedConstruction.close();

Finally

Since this is my first post, I'm not sure if I can explain it well. I hope it helps someone even a little. The Mock conversion method introduced this time is only a part. Both MockedStatic andMockedConstruction have several types of constructors, so [Mockito's official documentation](https://javadoc.io/static/org.mockito/mockito-core/3.5.9/org/mockito/ Please refer to Mockito.html) and try various things with IDE such as Android Studio.