How to use should_reset_invocations_on_multiple_mocks method of org.mockitousage.basicapi.ResetInvocationsTest class

The Spring Cache Manager relies on Spring managing the application. You can't get that with the PowerMockRunner, you need to use SpringJUnit4Runner. You can still use PowerMock or Mockito programmatically, but not as a Runner.

Typically, you'll turn your unit test into a Spring-style integration test, something like this:

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration
public class SpringTest {

    @Configuration
    @EnableCaching
    static class SpringConfig{
        @Bean
        public CustomerService customerService(){
            return new CustomerServiceImpl(customerRepository());
        }
        @Bean
        public CustomerRepository customerRepository(){
            return Mockito.mock(CustomerRepository.class);
        }
    }

    @Autowired
    CustomerService customerService; // this will contain a proper managed cache

    @Autowired
    CustomerRepository customerRepository; // this is a mockito mock you can fine-tune
}

Figured out.

The method being called was a parameterized method, but could not infer the parameter type from the matcher argument (the last argument was of type Class).

Making the explicit call

when(restTemplate.<Long>exchange(isA(URI.class),eq(HttpMethod.POST),isA(HttpEntity.class), eq(Long.class))).thenThrow(new RestClientException(EXCEPTION_MESSAGE));

fixed my problem.

You can create the future and return it using thenReturn(). In the case below, I create an already completed Future<List<String>> using CompletableFuture.

when(f1.methNew(anyString()))
        .thenReturn(CompletableFuture.completedFuture(Arrays.asList("A", "B", "C")));

Don't mock the InputStream. Instead, transform the String to an array of bytes using the getBytes() method. Then create a ByteArrayInputStream with the array as input, so that it returns the String when consumed, each byte at a time. Next, create a ServletInputStream that wraps a regular InputStream like the one from Spring:

public class DelegatingServletInputStream extends ServletInputStream {

    private final InputStream sourceStream;


    /**
     * Create a DelegatingServletInputStream for the given source stream.
     * @param sourceStream the source stream (never <code>null</code>)
     */
    public DelegatingServletInputStream(InputStream sourceStream) {
        Assert.notNull(sourceStream, "Source InputStream must not be null");
        this.sourceStream = sourceStream;
    }

    /**
     * Return the underlying source stream (never <code>null</code>).
     */
    public final InputStream getSourceStream() {
        return this.sourceStream;
    }


    public int read() throws IOException {
        return this.sourceStream.read();
    }

    public void close() throws IOException {
        super.close();
        this.sourceStream.close();
    }

}

and finally, the HttpServletRequest mock would return this DelegatingServletInputStream object.

To to this, you can use PowerMockito.spy(...) and PowerMockito.doReturn(...).

Moreover, you have to specify the PowerMock runner at your test class, and prepare the class for testing, as follows:

@PrepareForTest(Util.class)
@RunWith(PowerMockRunner.class)
public class UtilTest {

   @Test
   public void testMethod() throws Exception {
      PowerMockito.spy(Util.class);
      PowerMockito.doReturn("abc").when(Util.class, "anotherMethod");

      String retrieved = Util.method();

      Assert.assertNotNull(retrieved);
      Assert.assertEquals(retrieved, "abc");
   }
}

Hope it helps you.

Generally, don't mock the class under test. If your test is for a Person, you shouldn't ever see Mockito.mock(Person.class) in it, as that's a pretty clear sign that you're testing the mocking framework instead of the system-under-test.

Instead, you may want to create a spy(new Person()), which will create a real Person implementation using a real constructor and then copy its data to a Mockito-generated proxy. You can use MockingDetails.getInvocations() to reflectively check that every getter was called.

// This code is untested, but should get the point across. Edits welcome.
// 2016-01-20: Integrated feedback from Georgios Stathis. Thanks Georgios!

@Test
public void callAllGetters() throws Exception {
  Person personSpy = spy(new Person());
  personSpy.getFirstname();
  personSpy.getLastname();

  assertAllGettersCalled(personSpy, Person.class);
}

private static void assertAllGettersCalled(Object spy, Class<?> clazz) {
  BeanInfo beanInfo = Introspector.getBeanInfo(clazz);
  Set<Method> setOfDescriptors = beanInfo.getPropertyDescriptors()
      .stream()
      .map(PropertyDescriptor::getReadMethod)
      .filter(p -> !p.getName().contains("getClass"))
      .collect(Collectors.toSet());
  MockingDetails details = Mockito.mockingDetails(spy);
  Set<Method> setOfTestedMethods = details.getInvocations()
      .stream()
      .map(InvocationOnMock::getMethod)
      .collect(Collectors.toSet());
  setOfDescriptors.removeAll(setOfTestedMethods);
  // The only remaining descriptors are untested.
  assertThat(setOfDescriptors).isEmpty();
}

There might be a way to call verify and invoke on the Mockito-generated spy, but that seems very fragile, and very dependent on Mockito internals.

As an aside, testing bean-style getters seems like an odd use of time/effort. In general focus on testing implementations that are likely to change or break.

You can use ByteArrayOutputStream which writes the data in memory. You can read this with a ByteArrayInputStream.

An alternative is to write an expecting OutputStream which fails as soon as you attempt to write an incorrect byte. This can be helpful to see exactly where/why a test fails.

It sounds like you may want to be using the .expects(1) type methods that mock frameworks usually provide.

Using mockito, if you were testing a List and wanted to verify that clear was called 3 times and add was called at least once with these parameters you do the following:

List mock = mock(List.class);        
someCodeThatInteractsWithMock();                 

verify(mock, times(3)).clear();
verify(mock, atLeastOnce()).add(anyObject());      

Source - MockitoVsEasyMock

As a workaround you may run the tests through the gradle task window:

Use the command that you used for your run configurations:

gradle testDebugUnitTest --tests "your.package*"