Mockito/PowerMock when....then not being invoked? - junit

Question

When I execute the following test, the original object is being returned and not the mock, so the real method getLevelCriteriaForLevel(level) is being executed (I observed that with the debugger). Why is that so? I'm pretty sure that this already worked yesterday and I didn't change anything there.
I already tried
#PrepareForTest({LevelCriteria.class, LevelGenerator.class})
or used the MockitoJunitRunner as I did before, but this doesn't help either.
Here is the code (generateConcreteLevel is a private method. The expected exception is only thrown when I pass this data from the mock. Otherwise it's not thrown. The test fails because the exception is not thrown, because the test doesn't use the mock object but the real object):
public class LevelGenerator
{
public void createLevel(int level)
{
generateConcreteLevel(levelCriteria.getLevelCriteriaForLevel(level));
}
private void generateConcreteLevel(LevelCriterion levelCriterion)
{
int entryGroupCount = levelCriterion.getEntryGroupCount();
int exitGroupCount = levelCriterion.getExitGroupCount();
int exitsWhileEntries = levelCriterion.getExitsWhileEntries();
int maxGroupSize = levelCriterion.getMaxGroupSize();
List<Question> questions = levelCriterion.getQuestions();
int speed = levelCriterion.getSpeed();
Range blueItemsCount = levelCriterion.getBlueItemsCount();
Range brownItemsCount = levelCriterion.getBrownItemsCount();
Range greenItemsCount = levelCriterion.getGreenItemsCount();
Range redItemsCount = levelCriterion.getRedItemsCount();
Range whiteItemsCount = levelCriterion.getWhiteItemsCount();
Range timespanBetweenGroups = levelCriterion.getTimespanBetweenGroups();
float fractionOfCarAmountToLeave = levelCriterion.getFractionOfCarAmountToLeave();
float fractionOfMinimumItemsAmountInCarParkToStartExits = levelCriterion.getFractionOfMinimumItemsAmountInCarParkToStartExits();
checkItemsFitInEntryGroups(entryGroupCount, maxGroupSize, blueItemsCount, brownItemsCount, greenItemsCount, redItemsCount, whiteItemsCount);
}
private void checkItemsFitInEntryGroups(int entryGroupCount, int maxGroupSize, Range... ranges)
{
int totalRangeCount = 0;
for (Range range : ranges)
{
totalRangeCount += range.getMaximum();
}
if (totalRangeCount > entryGroupCount * maxGroupSize)
{
throw new UnsupportedOperationException("Error in level criterion: Not enough entry groups for Items.");
}
}
}
and the test...
#RunWith(PowerMockRunner.class)
public class LevelGeneratorTest
{
#Mock
private LevelCriteria levelCriteriaMock;
#InjectMocks
private LevelGenerator levelGenerator;
#Test(expected=UnsupportedOperationException.class)
public void tooLessPositionsInEntryGroups()
{
LevelCriterion levelCriterion = new LevelCriterion.LevelCriterionBuilder()
.withBlueItemsCount(new Range(10, 10))
.withEntryGroupCount(3)
.withExitGroupCount(3)
.withMaxGroupSize(3)
.build();
when(levelCriteriaMock.getLevelCriteriaForLevel(anyInt())).thenReturn(levelCriterion);
levelGenerator.createLevel(0);
}
}
By the way: It's not an Eclipse problem, since a Maven build produces the same error.
I know that I can execute the private method with PowerMockito's Whitebox directly what I will do after refactoring, but the question is, why when...then is not working here.

Answer 1

Assuming your question is:
Why is the real method getLevelCriteriaForLevel(level) executed when I expect to have the mocked implementation?
I will try to demonstrate that everything works as expected fine if you reproduce it is a simple example (switch from your current workspace if you need to).
I do not have you LevelCriterion.LevelCriterionBuilder() so I simplified your test by just instantiating a LevelCriterion (empty object). This is not relevant because in my implementation I will always return an UnsupportedOperationException.
Here is how my LevelGenerator looks like. The UnsupportedOperationException is as simple as possible LevelGenerator#generateConcreteLevel(LevelCriterion).
If implemented like this:
public class LevelGenerator
{
LevelCriteria levelCriteria;
public void createLevel(int level)
{
generateConcreteLevel(levelCriteria.getLevelCriteriaForLevel(level));
}
private void generateConcreteLevel(LevelCriterion levelCriteriaForLevel)
{
throw new UnsupportedOperationException("xxx");
}
}
The test is green, using a #RunWith(MockitoJUnitRunner.class) on top of LevelGeneratorTest.
I did not used #PrepareForTest or PowerMockRunner. I have Mockito version 1.9.5.
I am sure that I have not used the real getLevelCriteriaForLevel(level) implementation, because it looks like this:
public class LevelCriteria {
public LevelCriterion getLevelCriteriaForLevel(int level) {
throw new IllegalStateException("Unexpected call");
}
}
If the real getLevelCriteriaForLevel(int) is excuted the test is red (because an IllegalStateException is thrown).
And the test is still green...
This works with pure-Mockito (version 1.9.5) approach.
You should remove all other mocking library (PowerMock, EasyMock...)
Are you sure that your static call of when(..).thenReturn(..) is the Mockito one?
Have you tried: Mockito.when(..).thenReturn(..)
I hope it helps.
PS: I have seen that you updated the question. It is a little bit unfair for me, but I am not going to update my answer once again.
I do not need the implementation detail of generateConcreteLevel(..) to illustrate that the when(..) call is working. Read my answer again. Try it in a separate workspace and you will see by yourself.
PS-2: I am using Eclipse too... Why should it be a problem? Eclipse is a great IDE.

Answer 2

I figured out what's wrong. Unfortunately you don't see the real problem in this question since I simplified the classes:
My real implementation of LevelGenerator got a parameterized constructor today. That's the reason why it worked yesterday but not anymore. Obviously there are mock injection problems with Mockito when not using a standard constructor.
Result: The when...then works as excpected.