EasyMock and parameterized tests (JUnit parameterized)

Question

I would like to use @Mock on a class inside parameterized test class. But for some reasons mockClassB is NULL. My code similar to

@RunWith(Parameterized.class)
public class ClassATest extends EasyMockSupport {

    private String uniqueIdentifier;
    private String value;

    @Mock
    private ClassB mockClassB;

    public ClassATest(String uniqueIdentified, String value) {
        this.uniqueIdentifier = uniqueIdentified;
        this.value = value;
    }

    ...

    @Parameterized.Parameters(name = "{index}: id = {0}; value = {1}")
    public static Collection<Object[]> data() {
        return Arrays.asList(new Object[][]{
                {"1", "val1"},
                {"2", "val2"}});
    }

    @Test
    public void testMethod() {
        ...
        expect(mockClassB.someMethod(uniqueIdentifier)).andReturn(value);   // mockClassB is NULL
        replayAll();
        ....
    }
}

Is it possible to create a mocked object inside a parameterized class?

Answer 1

EasyMock needs a rule or a runner to instantiate the annotated mocks. Since you are already using a runner, your only option is a rule. The following will work.

@RunWith(Parameterized.class)
public class ClassATest extends EasyMockSupport {

    @Rule
    public EasyMockRule rule = new EasyMockRule(this);

    private String uniqueIdentifier;
    private String value;

    @Mock
    private ClassB mockClassB;

    public ClassATest(String uniqueIdentified, String value) {
        this.uniqueIdentifier = uniqueIdentified;
        this.value = value;
    }

    @Parameterized.Parameters(name = "{index}: id = {0}; value = {1}")
    public static Collection<Object[]> data() {
        return Arrays.asList(new Object[][]{
                {"1", "val1"},
                {"2", "val2"}});
    }

    @Test
    public void testMethod() {
        expect(mockClassB.someMethod(uniqueIdentifier)).andReturn(value);   // mockClassB is NULL
        replayAll();
    }
}

The alternative is to directly call injectMocks which is available on EasyMockSupport.

@RunWith(Parameterized.class)
public class ClassATest extends EasyMockSupport {

    private String uniqueIdentifier;
    private String value;

    @Mock
    private ClassB mockClassB;

    public ClassATest(String uniqueIdentified, String value) {
        this.uniqueIdentifier = uniqueIdentified;
        this.value = value;
    }

    @Before
    public void before() {
        injectMocks(this);
    }

    @Parameterized.Parameters(name = "{index}: id = {0}; value = {1}")
    public static Collection<Object[]> data() {
        return Arrays.asList(new Object[][]{
                {"1", "val1"},
                {"2", "val2"}});
    }

    @Test
    public void testMethod() {
        expect(mockClassB.someMethod(uniqueIdentifier)).andReturn(value);   // mockClassB is NULL
        replayAll();
    }
}