I am telling PowerMockito spy to return a value, so why is it calling the actual method?

Question

I am trying to test some code using a PowerMockito spy, and I am stubbing a method (getRootTagMap--see below) to return a value constructed in the tester, (Using PowerMockito, because the method is private .)

However instead of returning the value, it is always invoking the actual method, rather than returning the constructed value.

Not sure what I am doing wrong

import org.junit.Test;
import org.junit.runner.RunWith;
import org.powermock.core.classloader.annotations.PrepareForTest;
import org.powermock.modules.junit4.PowerMockRunner;

import static org.powermock.api.mockito.PowerMockito.spy;


@RunWith(PowerMockRunner.class)
@PrepareForTest({JsonAppMessageProcessor.class})
public class TestPropStoreAppController {
    @Test public void testSaveJsonAppTagChangesToPropStore() throws Exception {
        JsonAppMessageProcessor messageProcessorSpy = spy(new JsonAppMessageProcessor());
        when(messageProcessorSpy, "getRootTagMap", any(JsonAppTag.class)).thenReturn(constructReturnValue());
        // I tried it this way too...
        //  doReturn(constructReturnValue()).when(messageProcessorSpy, "getRootTagMap", any(JsonAppTag.class));
        // the following call calls the real getRootTagMap(JsonAppTag) method instead of returning the stub
        messageProcessorSpy.saveChanges(constructParameterForChanges());
    }
}

did you ever find out what was the problem ? I'm having the same problem right now and don't know what to do .. https://stackoverflow.com/questions/38155092/powermockito-is-calling-the-method-when-i-use-doreturn-when — Ahmad, Jul 01 '16 at 23:55

score 2 · Answer 1 · answered Jan 07 '15 at 20:55

I dont know what is the PowerMockito version you are using, but the following scenario works for me:

doReturn(constructReturnValue()).when(messageProcessorSpy).getRootTagMap(any(JsonAppTag.class));

The call of the method that you are mocking on a spy object should be called in the instance returned by the when method, and not inside it like in a regular mock object.

I am telling PowerMockito spy to return a value, so why is it calling the actual method?

1 Answers1

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