Question

Is it possible to mock the enterprise library 5 version of ‘Database’? If so… how?

There is no IDatabase interface (which is a mystery as I though Microsoft P&P would be more on the ball about testability benefits of exposing such an interface).

I have a Repository class which used EntLib 5 Data Access Application Block.

I am retro fitting unit tests into this class and need to mock out the dependency on the Database object. This class is now passed the Database via its constructor and uses a Database object to perform operations on the Db.

I use the following to resolve an instance of the Database to be passed to my Repository:

Container.RegisterType<IFooRepository, FooRepository>(
    new InjectionConstructor(
        EnterpriseLibraryContainer.Current.GetInstance<Database>("FooDbConnStr")
    )
);

I don’t wish these unit tests to become integration tests.

I have tried using Moq to create a dynamic mock of the Database type, but this has proved tricky as Database requires a connection string and a DbProviderFactory in its constructor. Maybe if there was such a thing as a MockDbProviderFactory.

This is the form that the unit test is taking:

Aside: I also find the use of a static logger class very difficult to test. Hopefully I am missing some trick here, but I must say I am disappointed with testability thus far.

Answer 1

I used FakeItEasy http://code.google.com/p/fakeiteasy/.

I created a mock of SqlDatabase (inherits from Database with a friendlier constructor) passed it to the FooRepostory, called the function under test and asserted expected calls that were made to the Database.

[Test]
public void FooRepo_CallsCorrectSPOnDatabase()
{
    var mockDb = A.Fake<SqlDatabase>(x => x.WithArgumentsForConstructor(new object[] { "fakeconnStr" }));
    var sut = new FooRepository(mockDb);
    sut.LoadFoosById(1);
    A.CallTo(() => mockDb.GetStoredProcCommand(Db.SProcs.GetFoosById)).MustHaveHappened(Repeated.Once);
}