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I’ve been spending the better part of two days doing this same process over and over. It doesn’t feel like I’m testing anything of value.

I am not doing it in the C# 3.0ish way, but it is better to explain it that way. I have a class and a façade (MyFacade) that I want to extend and test.

class Foo {
     public string Name { get; set; }
}

class MyFacade {
     public IMyDependency Depend { get; set; }
}

interface IMyDependency {
     IList<Foo> GetAllFoos();
}

So I write my test first like a good boy person should. I know my façade should give me back a list of the Name properties from the Foo objects it knows about.

[TestFixture]
public class MyFacadeTests {
    [Test]
    public void GetFooNames_ReturnsOnlyName() {
        FakeDependancy fake = new FakeDependency();
        MyFacade m = new MyFacade() { Depend = fake };
        Assert.That(m.GetFooNames(), Is.EquivalentTo(fake.FakeFoos.Select(x => x.Name)));
    }
}

I need that FakeDependency, so I go ahead and create that. This would be a like my repository that will allow me to initialize the fake data.
class FakeDependency : IMyDependency {

    // My local fake repository
    public IList<Foo> FakeFoos = new List<Foo>{
                new Foo{ Name="A"},
                new Foo{ Name="B"},
                new Foo{ Name="B"}};

    public IList<Foo> GetAllFoos() {
        return FakeFoos;
    }
}

OK. So now that I have that, I add my GetFooNames stub to MyFacade.

class MyFacade {
    public IMyDependency Depend { get; set; }

    public IList<string> GetFooNames()
    {
        return null;
    }
}

Run my test. It fails. Good. Now to implement that method….uhh I just copy my assert statement:

fake.FakeFoos.Select(x => x.Name)

…replace “fake.FakeFoos” with “Depend.GetAllFoos()” and I get:

class MyFacade {
    public IMyDependency Depend { get; set; }

    public IEnumerable<string> GetFooNames() {
        return Depend.GetAllFoos().Select(x => x.Name);
    }
}

Build it. Run it. It passes. What did I really test since I just copied the assert statement into the implementation body and changed the source? Did I test anything? That my copy code does the same thing in two places? Am I wasting time?
I rolled it around with a friend and decided to take out the select in the assert statement and replace it with a declarative list so it would look like this:

Assert.That(m.GetFooNames(), Is.EquivalentTo(new[]{"A","B","C"}));

That make me feel a little less “copy and pastey”, but now I have to know my fake is setup to give me three letters for the names. Let’s add a little bit to the fake to make it easier to configure. I am hesitant to do this since I don’t want to add code to my test classes, but I think in the end it is more readable than a more raw configuration.
So I added this to my test class:

public FakeDependency With(int i)
{
    FakeFoos.Clear();
    for (int j = 0; j < i; j++)
    {
        FakeFoos.Add(new Foo());
    }
    return this;
}

public FakeDependency Named(string name)
{
    for (int i = 0; i < FakeFoos.Count; i++)
    {
        // We want them to be 1 based and not zero based
        FakeFoos[i].Name = string.Format("{0} {1}", name, i + 1);
    }
    return this;
}

And use it in my test like this:

[Test]
public void GetFooNames_ReturnsOnlyName() {
    FakeDependency fake = new FakeDependency().With(3).Named("Fake");
    MyFacade m = new MyFacade() { Depend = fake };
    Assert.That(m.GetFooNames(), Is.EquivalentTo(new[]{"Fake 1","Fake 2","Fake 3"}));
}

I’m a lot happier with that than copying the same code from the test to the implementation classes.

Here is another cool one….at least to me. In my test classes I’ve been trying to fake out my dependencies instead of mock them…just for a change and most of the time I don’t really want to assert how the class used the dependency, just that it gives me the correct result.

I create nested private classes using ReSharper. It puts it at the bottom of my current class which is fine. However, all that is noise to me for the most part, so I moved them to a partial class. I have MyClassTests and MyClassFakes, which actually has a MyClassTests partial class that holds…you guessed it, all the fakes….Anyway, here is how ReSharper will move my classes around. It’ll move whatever, is selected. In this case I’m moving my field bar, but in real life I move my nested class.

With my cursor on bar, I use the trusty Alt + Enter. And tell it to move it.

It moves it down to the other part.

More than one partial class? No problem.