[FIXED] How to mock StorageOptions.newBuilder()

Issue

Can you help me in mocking StorageOptions.newBuilder()

Code to be Mocked:

StorageOptions.newBuilder.setProjectId("Test").build().getService()

Code I have written:

Storage mockStorage = Mockito.mock(Storage.class);

MockedStatic<StorageOptions> storageOptionsMock = Mockito.mockStorage(StorageOptions.class);
storageOptionsMock.when( ()-> StorageOptions.newBuilder().setProjectId("Test").build().getService()).thenReturn(mockStorage);

Error:

org.mockito.exceptions.misusing.WrongTypeOfReturnValue: 
Storage$MockitoMock$1939527098 cannot be returned by newBuilder()
newBuilder() should return Builder

Solution

Since you are chaining a lot of method calls, you can use Mockito.RETURNS_DEEP_STUBS to instruct Mockito to return all the required intermediate stubs/mocks.

Storage mockStorage = Mockito.mock(Storage.class);
MockedStatic<StorageOptions> storageOptionsMock = 
    Mockito.mockStatic(StorageOptions.class, Mockito.RETURNS_DEEP_STUBS);

storageOptionsMock.when(()->  
    StorageOptions.newBuilder()
                  .setProjectId("Test")
                  .build()
                  .getService())
.thenReturn(mockStorage);

assertThat(StorageOptions.newBuilder()
    .setProjectId("Test")
    .build()
    .getService())
.isEqualTo(mockStorage);

But since this is considered an anti pattern, you may want to refactor your code to avoid this.

Answered By - gere
Answer Checked By - David Goodson (JavaFixing Volunteer)