EasyMock throwing incompatible return value type on final method

Question

Basically, I'm trying to set the result of a final method. The method is simple, like this:

@NotNull
public final Server getServer() {
    return this.server;
}

I mock it like this:

EasyMock.expect(object.getServer()).andReturn(server);

Where server is a POJO. This throws this:

java.lang.IllegalStateException: incompatible return value type
    at org.easymock.internal.MocksControl.andReturn(MocksControl.java:281)

For that line. I tried not using a POJO for server, and mocking it instead.

@Mock
private Server server = mock(Server.class);

Yet still the same error. I'm absolutely positive that they are the exact same type. Why is this happening?

Now, for some reason I get a different error:

java.lang.IllegalStateException: no last call on a mock available

Same code, all I have is this:

@Test
public void test() {
    EasyMock.expect(object.getServer()).andReturn(server);
    replayAll();
    TestedObject.useObject(object);
}

Answer 1

The reason you get an error when mocking a final method is that it is not supported by EasyMock. https://easymock.org/user-guide.html#mocking-limitations

Final methods cannot be mocked. If called, their normal code will be executed.

You can use PowerMock to mock final and static methods.