MbUnit now supports setting dependencies between fixtures, similarly to NAnt/MSBuild task dependencies.

How-to

The logic is simple. You can tag a fixture with the DependsOnAttribute to specify a "parent" fixture that should be run before the current fixture. If the parent fixture fails, the current fixture is not run:

[TestFixture]
public class Parent
{...}

[TestFixture]
[DependsOn(typeof(Parent))]
public class Child
{...}

The Child fixture is executed if the Parent fixture executed successfully.

Why do we need dependencies between fixtures ?

Image that you are testing a database. At first, you create a fixture that tests that the connection is correct:

[TestFixture]
public class ConnectionTest
{ ... }

If one of the tests of ConnectionTest fails, then it is likely that all the tests that rely on a database connection will fail and, therefore, should not be executed. Using the DependsOnAttribute, you can specify the dependency of such fixture to the ConnectionFixture.

[TestFixture]
[DependsOn(typeof(Connection))]
public class DALTest
{...}

An example

The following example defines 4 fixture. Child depends on Parent and SickParent, GrandChild depends on Child. Since SickParent has a failed test, Child and GrandChild should not be executed...

[TestFixture]
[CurrentFixture]
public class Parent
{
    [Test]
    public void Success()
    {}
}

[TestFixture]
[CurrentFixture]
public class SickParent
{
    [Test]
    public void Failure()
    {
        throw new Exception("boom");
    }
}

[TestFixture]
[CurrentFixture]
[DependsOn(typeof(Parent))]
[DependsOn(typeof(SickParent))]
public class Child
{
    [Test]
    public void Success()
    {
    }
}

[TestFixture]
[CurrentFixture]
[DependsOn(typeof(Child))]
public class GrandChild
{
    [Test]
    public void Success()
    {}
}

The report result is shown below and one can see that Child and GrandChild fixture have failed without being executed.