Output Parameters in Argument Constraints with Rhino Mocks… Again!

One of my favorite things about being a blog owner and operator is when I’m looking for something and find that I’ve already answered my own question. This just happened to me as I was trying to re-figure out how to use output parameters with argument constraints with Rhino Mocks.

I found an article on this very topic written by me (thanks, self!), but as I was reading I noticed that I left something important out. So here’s a quick, mini do-over!

Let’s say we need to stub function Bar as it’s defined in the following interface:

public interface IFoo
{
    bool Bar(out string outty);
}

To use an argument constraint with the output argument, I need to do two things. First, I need to use Arg<T>.Out. The second thing–the thing that I failed to mention in my previous post–is that I need to use the Dummy property to make it compile.

Here’s what an example might look like. I stubbed the Bar function to return true and assign the value fake value! to the output argument.

IFoo mockFoo = MockRepository.GenerateMock<IFoo>();
mockFoo(x => x.Bar(out Arg<string>.Out("fake value!").Dummy)).Return(true);

Not too shabby!

Advertisements

Leave a comment

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s