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c#dependency-injectionmockingfakeiteasyautomocking

Create class and auto-initialize dependencies with FakeItEasy

Is it possible to create a class under test with FakeItEasy, where all dependencies that are declared in the constructor are initialized automatically with fakes?

Imagine the class:

public class Inserting
{
    public Inserting(
        ITransactionService transactionService,
        ISharedData sharedData)
    {
        TransactionService = transactionService;
        SharedData = sharedData;
    }

    public ITransactionService TransactionService { get; }

    public ISharedData SharedData { get; }

    public void Enter()
    {
        TransactionService.StartTransaction();
    }
}

Then I am creating all fake-objects in the test setup and construct my class under test with those fakes:

public class InsertingTest
{
    private Inserting _inserting;
    private ISharedData _fakeSharedData;
    private ITransactionService _fakeTransactionService;        

    [SetUp]
    public void SetUp()
    {
        _fakeTransactionService = A.Fake<ITransactionService>();
        _fakeSharedData = A.Fake<ISharedData>();

        _inserting = new Inserting(_fakeTransactionService, _fakeSharedData);
    }

    [Test]
    public void TestEnter()
    {
        // Arrange

        // Act
        _inserting.Enter();

        // Assert
        A.CallTo(() => _fakeTransactionService.StartTransaction().MustHaveHappened();
    }
}

But I saw in the Java-world, that when using Mockito and Dagger 2, you can do something like this:

public class PhoneDialer {
    private Activity activity;
    private PhoneCallListener phoneCallListener;

    @Inject
    public PhoneDialer(Activity activity, PhoneCallListener phoneCallListener) {
        this.activity = activity;
        this.phoneCallListener = phoneCallListener;
    }
}

public class PhoneDialerTest {
    @Rule
    public MockitoRule mockitoRule = MockitoJUnit.rule();

    @Mock
    PhoneCallListener phoneCallListener;

    @Mock
    Activity activity;

    @InjectMocks
    PhoneDialer dialer;

    @Test
    public void test_dialer() throws Exception {
        // Arrange

        // Act
        dialer.callNumber("abc");

        // Assert
        Mockito.verify(phoneCallListener, times(1)).startCall();
    }
}

and the mocked classes are initialized automatically with fakes. Is there an equivalent procedure or function in C# with FakeItEasy?

Solution

  • I think you want something like Automatically inject fakes in test fixture with FakeItEasy. You use [Fake] to mark fakes to inject and [UnderTest] to mark the production type to test.

    We really should put this into the documentation.

    Alternatively,