Version du 25 septembre 2020 à 17:34

Configuration

In JUnit 5, the @RunWith annotation has been replaced by the more powerful @ExtendWith annotation.

Before & After

@Before @After

The method with this annotation is executed before or after every test method

@BeforeClass @AfterClass

The method with this annotation is executed before or after every test class

Parametrize Test

• On top of the test class @RunWith(Parameterized.class)
• method annotated with @Parameter is passing Arrays.asList()

Mockito

Mocks vs Stubs = Behavioral testing vs State testing

Mockito does not allow Stubbid final & Private methods

Stubbing

Empty class, only return the expected

• cannot be dinamically created from code

MyMockedService myMockedService = new MyMockedService();
stub(myMockedService.methodToTest("param")).return("value");

Test lifecycle with stubs:

• Setup - Prepare object that is being tested and its stubs collaborators.
• Exercise - Test the functionality.
• Verify state - Use asserts to check object's state.
• Teardown - Clean up resources.

Stubbing Variations

• Argument Matchers

Spy

A Spy is a Stub than is also collecting informations during the test

Used on legacy system where you don't really have access to the code or dependencies

• • How many times this method is called ?
  • Is this method is called at least once ?

Mock

Fullclass with implementation, same comportement as in real code.

• Creating Objects that simulate the behavior of real objects
• can be dynamically created from code - at runtime
• offer more fonctionnalities than stubbing
  • How many times this method is called ?
  • Is this method is called at least once ?

MyMockedService myMockedService = mock(MyMockService.class);
when(myMockedService.methodToTest("param")).thenReturn("value");

Test lifecycle with mocks

• Setup data - Prepare object that is being tested.
• Setup expectations - Prepare expectations in mock that is being used by primary object.
• Exercise - Test the functionality.
• Verify expectations - Verify that correct methods has been invoked in mock.
• Verify state - Use asserts to check object's state.
• Teardown - Clean up resources.

Argument Matchers

Mockito extends Matchers and theses methods are available

• any()
• anyString()
• anyList()
• ...

Exceptions

//To prevent from failing when an exception is thrown
@Test(expected=RuntimeException.class)

Annotations

@Mock

Mockito automatically creates a Mock of this class needs @RunWith(MockitoJunitRunner.class)

@InjectMocks

// Every time we use TodoBusinessImpl  we want to inject todoServiceMock
@Mock TodoService todoServiceMock;
when(todoServiceMock.retrieveTodos("dummy"))).thenReturn(todos);
// todoServiceMock is injected as a constructor parameter
TodoBusinessImpl todoBusinessImpl = new TodoBusinessImpl(todoServiceMock)

Instead of previous code, mockito can help

// Every time we use TodoBusinessImpl  we want to inject todoServiceMock
@Mock TodoService todoServiceMock;
@InjectMocks TodoBusinessImpl todoBusinessImpl ;
when(todoServiceMock.retrieveTodos("dummy"))).thenReturn(todos);
// Replaced with Injected 
// MocksTodoBusinessImpl todoBusinessImpl = new TodoBusinessImpl(todoServiceMock)

@Captor

//@Captor ArgumentCaptor .. lets see later

@MockBean