title: How do I run NUnit in debug mode from Visual Studio?
body: <p>I've recently been building a test framework for a bit of C# I've been working on. I have NUnit set up and a new project within my workspace to test the component. All works well if I load up my unit tests from Nunit (v2.4), but I've got to the point where it would be really useful to run in debug mode and set some break points.</p>
  
  <p>I've tried the suggestions from several guides which all suggest changing the 'Debug' properties of the test project:</p>
  
  <pre><code>Start external program: C:\Program Files\NUnit 2.4.8\bin\nunit-console.exe
  Command line arguments: /assembly: &lt;full-path-to-solution&gt;\TestDSP\bin\Debug\TestDSP.dll
  </code></pre>
  
  <p>I'm using the console version there, but have tried the calling the GUI as well. Both give me the same error when I try and start debugging:</p>
  
  <pre><code>Cannot start test project 'TestDSP' because the project does not contain any tests.
  </code></pre>
  
  <p>Is this because I normally load \DSP.nunit into the Nunit GUI and that's where the tests are held?</p>
  
  <p>I'm beginning to think the problem may be that VS wants to run it's own test framework and that's why it's failing to find the NUnit tests?</p>
  
  <p><strong>Edit</strong>: To those asking about test fixtures, one of my .cs files in the TestDSP project looks roughly like this:</p>
  
  <pre><code>namespace Some.TestNamespace
  {
      // Testing framework includes
      using NUnit.Framework;
  
      [TestFixture]
      public class FirFilterTest
      {
          [Test]
          public void Test01_ConstructorTest()
          {
              ...some tests...
          }
      }
  }
  </code></pre>
  
  <p>...I'm pretty new to C# and the NUnit test framework so it's entirely possible I've missed some crucial bit of information ;-)</p>
  
  <p><strong>Final Solution</strong>: The big problem was the project I'd used. If you pick <code>Other Languages -&gt; Visual C# -&gt; Test -&gt; Test Project</code> ...when you're choosing the project type, Visual Studio will try and use it's own testing framework as far as I can tell. You should pick a <strong>normal</strong> C# class library project instead and then the instructions in my selected answer will work.</p>