Testing DAOs : the SetUpFixture Attribute

Usually I’m testing DAOs for CRUD operations. Using NHibernate, as persistent layer, what we are testing, in practice, is the mapping and all behavior we have defined in it (cascade, associations, types, user-types, custom-collections and so on).

For CRUD operation I mean single entity instance CRUD without test complex queries (to test complex-queries I’m using a different test suite with a Well-Known-Data-Base).

Testing NHibernate DAO implementation

The first step is the test of the generic/base implementation of the DAO. To test it I’m mocking NHibernate.

[Test]
public void Get_call_Get()
{
 // Arrange
 var sessionFactory = new Mock<ISessionFactory>();
 var session = new Mock<ISession>();
 sessionFactory.Setup(x => x.GetCurrentSession()).Returns(session.Object);

 // Act
 var dao = new Dao<FakeEntity, int>(sessionFactory.Object);
 dao.Get(123);

 // Assert
 session.Verify(x => x.Get<FakeEntity>(It.Is<int>(id => id == 123)));
}

The CRUD test

A simple integration CRUD test may look like this:

[TestFixture]
public class MagazineTest
{
 [Test]
 public void MinimalCrud()
 {
     const int poid = 1;
     var m = new Magazine(poid) {Title = "some title"};

     var dao = new EntityDao<Magazine>(ServiceLocator.Current.GetInstance<ISessionFactory>());

     using (new PersistenceRequest())
     {
         dao.MakePersistent(m);
         ActionAssert.NotThrow(()=> dao.MakePersistent(m));
     }

     using (new PersistenceRequest())
     {
         var e = dao.Get(poid);
         e.Should().Not.Be.Null();
         e.Title.Should().Be.EqualTo("some title");
     }

     using (new PersistenceRequest())
     {
         var e = dao.Get(poid);
         e.Title = "different title";
     }

     // should update through NHibernate's UoW
     using (new PersistenceRequest())
     {
         var e = dao.Get(poid);
         e.Title.Should().Be.EqualTo("different title");
     }

     // Delete
     using (new PersistenceRequest())
     {
         var e = dao.Get(poid);
         dao.MakeTransient(e);
     }

     using (new PersistenceRequest())
     {
         var e = dao.Get(poid);
         e.Should().Be.Null();
     }
 }
}

The PersistenceRequest is an utility class I’m using to simulate the behaviour of the IHttpModule implementing the session-per-request pattern.

Note, the test-fixture does not inherit from a base class and does not have a any SetUp nor TearDown but indeed it need, at least, the configuration of the ServiceLocator, the configuration of NHibernate, the creation of schema, and so on.

For the whole CRUD-test-suite I want execute the configuration of the ServiceLocator, the configuration of NHibernate and its SessionFactory, just only one time and not before execute each test-fixture.

The SetUpFixture Attribute

Since few versions NUnit has a very useful feature: the SetUpFixture Attribute.

To have only one initialization, for all my CRUD-tests, I’m putting all test-fixtures starting from a specific namespace (in the image the namespace is “Cruds”) where I have the implementation of the class, marked with the [SetUpFixture], responsible to create the context for all CRUD tests.

The implementation of the CRUD context look like:
[SetUpFixture]

public class CrudTestContext
{
 private WindsorContainer container;

 [SetUp]
 public void Configure_NHibernate_and_ServiceLocator()
 {
     container = new WindsorContainer();
     container.Register(Component.For<IServiceLocator>()
         .Instance(new WindsorServiceLocator(container)));
     ServiceLocator.SetLocatorProvider(() => container.Resolve<IServiceLocator>());

     container.Register(Component.For<ISessionWrapper>()
         .ImplementedBy<FakeSessionWrapper>());
     container.Register(Component.For<IConfigurationProvider>()
         .ImplementedBy<NhTestConfigurationProvider>());
     container.Register(Component.For<ISessionFactoryProvider>()
         .ImplementedBy<SessionFactoryProvider>());
     container.Register(Component.For<ISessionFactory>()
         .Instance(container.GetService<ISessionFactoryProvider>().GetFactory(null)));
 }

 [TearDown]
 public void Close_NHibernate()
 {
     container.Dispose();
 }
}

public class NhTestConfigurationProvider : DefaultSessionFactoryConfigurationProvider
{
 public NhTestConfigurationProvider()
 {
     AfterConfigure += ValidateOrCreateSchema;
 }

 private void ValidateOrCreateSchema(object sender, ConfigurationEventArgs e)
 {
     try
     {
         new SchemaValidator(e.Configuration).Validate();
     }
     catch (HibernateException)
     {
         var export = new SchemaExport(e.Configuration);
         export.Drop(false, true);
         export.Create(false, true);
     }
 }
}

If you want use the [SetUpFixture] you must use a NUnit2.5 compatible test-runner (ReSharper 4.5 does not support it).

UPDATE : I'm sorry, ReSharper 4.5 does SUPPORT it.