如何使用Google Drive API（Java客户端）对应用程序进行单元测试

Question

What is the best way to unit test an application using the Google Drive API (Java client) ?

It seems like applications written rely heavily on the Drive class, but short of either...

• creating a really extensive mock (which, itself, would likely need to be tested), or
• writing an integration test dependent on the actual Drive service

...how could such an application be tested?

Using mock frameworks like Mockito are a bit tedious with the Drive API (Java client), since usage of the Drive Java client rely on making so many chained calls (eg, from the documentation):

Drive service = getDriveService(req, resp);
service.files().get(fileId).execute();

Answer 1

It shouldn't be that tedious in Mockito in fact, with the help of deep stub:

Drive mockDrive = mock(Drive.class, RETURNS_DEEP_STUBS);

....
// stubbing
when(service.files().get(anyString()).execute()).thenReturn(something);

// verify
verify(service.files().get("Some Field ID").execute();

Learn more from documentation of Mockito

It is fine if you write integration test to test against the actual Drive service, but it simply cannot replace unit testing.