UsingFactories alternative in MbUnit v3.

Question

Dear ladies and sirs.

I am trying to figure out how to write combinatorial test in MbUnit v3. All of the sample code on the web refers to MbUnit v2, which means using 3 attributes:

• CombinatorialTest
• Factory
• UsingFactories

In MbUnit v3 there is no UsingFactories attribute (and the Factory attribute semantics is widely different and CombinatorialTest attribute is no longer needed). So how can I tell which factory method bind to which parameter in the particular unit test method?

Thanks.

Answer 1

I remember an article from Jeff Brown, the lead developer of Gallio/MbUnit, which talks about dynamic and static factories in MbUnit v3. There is a nice example which describes how to create static and dynamic test factories.

In the other hand, test data factories are easier to create, and provide an interesting alternative to the [Row]-based data-driven tests, which only accept primitive values as input (a limitation of C# for the parameters passed to an attribute)

Here is an example for MbUnit v3. The data factory is here a property of the test fixture, but it can be a method or a field, which may be located in a nested type or in an external type. This is indeed a very flexible feature :)

[TestFixture]
public class MyTestFixture()
{
   private IEnumerable<object[]> ProvideTestData
   {
      get
      {
          yield return new object[] { new Foo(123), "Hello", Color.Blue};
          yield return new object[] { new Foo(456), "Big", Color.Red};
          yield return new object[] { new Foo(789), "World", Color.Green};
      }
   }

   [Test, Factory("ProvideTestData")]
   public void MyTestMethod(Foo foo, string text, Color color)
   {
      // Test logic here...   
   }
}

Answer 2

I don't see anything similar to [UsingFactories] in MbUnit's tests, but you could use [Factory] + this combinatorics library to achieve the same result.

Try asking on the MbUnit users group for a confirmation on this.

Answer 3

I have found out, with Jeff's help, that the Factory attribute can simply be used instead of UsingFactories, like so:

public static IEnumerable<int> XFactory()
{
...
}

public static IEnumerable<string> YFactory()
{
...
}

[Test]
public void ATestMethod([Factory("XFactory")] int x, [Factory("YFactory")] string y)
{
...
}

The test ATestMethod will be run on the cartesian multiplication of values generated by XFactory and those generated by YFactory.