Mockito - Bullying List Injection

Question

I have the following code:

@Component 
public class Wrapper
{ 
    @Resource 
    private List<Strategy> strategies;

    public String getName(String id)
    {
    // the revelant part of this statement is that I would like to iterate over "strategies"
        return strategies.stream()
            .filter(strategy -> strategy.isApplicable(id))
            .findFirst().get().getAmount(id);
    } 
}

---

@Component 
public class StrategyA implements Strategy{...}

@Component 
public class StrategyB implements Strategy{...}

I would like to create a test for it using Mockito. I wrote the test as follows:

@InjectMocks
private Wrapper testedObject = new Wrapper ();

// I was hoping that this list will contain both strategies: strategyA and strategyB
@Mock
private List<Strategy> strategies;

@Mock
StrategyA strategyA;

@Mock
StrategyB strategyB;

@Test
public void shouldReturnNameForGivenId()
{   // irrevelant code...
    //when
    testedObject.getName(ID);
}

I get a NullPointerException in the line:

filter(strategy -> strategy.isApplicable(id))

which states that the list of "strategies" is initialized but empty. Is there a way Mojito will behave just like Spring? Adding automatically all instances that implement the Strategy interface to the list?

Btw I have no settings in the Wrapper class, and I would like to leave it that way, if possible.

Answer 1

Mockito cannot know that you want to add something to the list strategy.

, -

@InjectMocks
private Wrapper testedObject = new Wrapper ();

private List<Strategy> mockedStrategies;

@Mock
StrategyA strategyA;

@Mock
StrategyB strategyB;

@Before
public void setup() throws Exception {
    mockedStrategies = Arrays.asList(strategyA, strategyB);
    wrapper.setStrategies(mockedStrategies);
}

Answer 2

.

:

private List<Strategy> strategies; // not mocked!

@Mock
StrategyA strategyA;

@Mock
StrategyB strategyB;

@Before
public void setup(){
  strategies= Arrays.asList(strategyA,strategyB);
  testedObject.strategies= strategies;
}

@Test
public void shouldReturnNameForGivenId()
{   // irrevelant code...
    //when
    testedObject.getName(ID);
}

Answer 3

@Spy @Mock. Mockito , , ArrayList. mocks . , .

@InjectMocks
private Wrapper testedObject = new Wrapper();

@Spy
private ArrayList<Strategy> mockedStrategies;

@Mock
private StrategyA strategyA;

@Mock
private StrategyB strategyB;

@Before
public void setup() throws Exception {
    mockedStrategies.add(strategyA);
    mockedStrategies.add(strategyB);
}

Answer 4

toStream()?

@InjectMocks
private Wrapper testedObject = new Wrapper();

private List<Strategy> mockedStrategies;

@Mock
StrategyA strategyA;

@Mock
StrategyB strategyB;

@Before
public void setup() {
    when(strategies.stream()).thenReturn(Stream.of(strategyA, strategyB));
}

, , .