Org. Mockito. Exceptions. Misusing. Missingmethodinvocationexception
I Am Getting Following Exceptions When I Run Junit Test. Org. Mockito. Exceptions. Misusing. Missingmethodinvocationexception: When() Requires an Argument...
I am getting following exceptions when I run Junit test.
org.mockito.exceptions.misusing.MissingMethodInvocationException:
when() requires an argument which has to be 'a method call on a mock'. For example:
when(mock.getArticles()).thenReturn(articles);Also, this error might show up because:
- you stub either of: final/private/equals()/hashCode() methods. Those methods cannot be stubbed/verified.
- inside when() you don't call method on mock but on some other object.
- the parent of the mocked class is not public. It is a limitation of the mock engine.
Following is my code and the exception was thrown at the second when statement. I don't think that my test code didn't violate what the exception claims. I spent for a while, but couldn't figure out. Could someone help? What I need to test is getPermProducts method. In the getPermProducts method, I want to ignore isTempProduct method. So, when p1 came, I want it returns false, and when p2 came, I want it returns true etc..
@Named(ProductManager.NAME)
public class ProductManager {
@Resource(name = ProductService.NAME)
private ProductService productService;
public List<Product> getPermProducts(Set<Product> products) {
Iterator<Product> it = products.iterator();
List<Product> cProducts = new ArrayList<Product>();
Product p;
while (it.hasNext()) {
p = it.next();
if (!isTempProduct(p)) {
cProducts.add(p);
}
}
return cProducts;
}
public Boolean isTempProduct(Product product) {
if (product instanceof PermProduct) {
return false;
}
Set<ProductItems> pItems = product.getProductItems();
if (pItems.isEmpty()) {
return false;
}
Iterator<ProductItem> itr = pItems.iterator();
while (itr.hasNext()) {
if (itr.next() instanceof TempItem) {
return true;
}
}
return false;
}
public Product getProduct(Integer productId) {
Product p = productService.getProduct(productId);
return p;
}
}
@RunWith(MockitoJUnitRunner.class)
public class ProductManagerTest {
@InjectMocks
private ProductManager mockProductManager;
@Mock
private ProductService mockProductService;//not being used here
private static final Integer PRODUCT_ID_1 = 1;
private static final Integer PRODUCT_ID_2 = 2;
@Test
public void getProduct(){
Product p1 = mock(PermProduct.class);
p1.setProductId(PRODUCT_ID_1);
when(mockProductManager.getProductId()).thenReturn(PRODUCT_ID_1);
when(mockProductManager.isTempProduct(p1)).thenReturn(false);
Product p2 = mock(TempProduct.class);
p2.setProductId(PRODUCT_ID_2);
when(mockProductManager.isTempProduct(p2)).thenReturn(true);
List<Product> products = Mock(List.class);
products.add(p1);
products.add(p2);
Iterator<Product> pIterator = mock(Iterator.class);
when(prodcuts.iterator()).thenReturn(pIterator);
when(pIterator.hasNext()).thenReturn(true, true, false);
when(pIterator.next()).thenReturn(p1, p2);
asserEquals(1, mockProductManager.getPermProducts(products).size());
}
}
SOLUTION: I updated my test based on enterbios's answer. I used partial mocking, but as enterbios suggested, we should avoid it, but sometimes we need it. I found that we can have both non-mocked and partial mocked class same time.
@RunWith(MockitoJUnitRunner.class)
public class ProductManagerTest {
@InjectMocks
private ProductManager productManager;//not being used here
@Mock
private ProductService mockProductService;//not being used here
@Spy
private OtherService other = new OtherService();//not being used here
@InjectMocks
final ProductManager partiallyMockedProductManager = spy(new ProductManager());
private static final Integer PRODUCT_ID_1 = 1;
private static final Integer PRODUCT_ID_2 = 2;
@Test
public void getProduct() {
Product p1 = new PermProduct();
p1.setProductId(PRODUCT_ID_1);
Product p2 = new Product();
p2.setProductId(PRODUCT_ID_2);
List<Product> products = new ArrayList<Product>();
products.add(p1);
products.add(p2);
doReturn(false).when(partiallyMockedProductManager).isTempProduct(p1);
doReturn(true).when(partiallyMockedProductManager).isTempProduct(p2);
assertEquals(1, partiallyMockedProductManager.getPermProducts(products).size());
verify(partiallyMockedProductManager).isTempProduct(p1);
verify(partiallyMockedProductManager).isTempProduct(p2);
}
}
1 Answer
Your mockProductManager is actually not a mock but an instance of ProductManager class. You shouldn't mock a tested object. The way to mock some methods from tested object is using a spy but I recommend you to not use them, or even to not think about them unless you're fighting with some ugly legacy code. I think your second 'when' should be replaced with assertion, like:
assertFalse(mockProductManager.isTempProduct(p1));
because what you really want to check in this test is if productManager.isTempProduct(p1) returns false for all instances of PermProduct. To verify results of some method calls/objects states you should use assertions. To make your life with assertions easier you can take a look on some helpful libraries like Hamcrest or FEST (). FEST is simpler for beginners I think.