Debugging Nunit tests in Visual Studio C# Express 2010

Question

I've followed this advice to get debugging working for NUnit tests.

http://www.blackwasp.co.uk/NUnitCSharpExpress.aspx

However, i have several tests that do Assert.Throws<...>, which causes the debugger to break when the exception i'm testing for occurs, when really i want it to break if an exception occurs outside of those calls.

How can i get the debugger to ignore exceptions caused from within these kinds of methods?

---

EDIT: I've event tried the below, which doesn't work!

[Test]
public void InstanciatingWithNullParameterThrowsException()
{
    try
    {
        Assert.Throws<ArgumentNullException>(() => new CachedStreamingEnumerable<int>(null));
        // This still throws and stops be being able to debug tests called after this one
    }
    catch
    {

    }
}

Answer 1

Here is what worked for me (although in Visual Studio Professional, not Express, but I guess that should not matter).

• Bring up the "Exceptions" Dialog as suggested by Ninjapig.

• Click on the Add... Button, to open the "New Exception" dialog.

• Select "Common Language Runtime Exceptions" in the drop down box
• In the Edit box enter "NUnit.Framework.AssertionException".
• Click OK to close the "New Exception" dialog.
• Back in the "Exceptions" dialog make sure that both checkboxes (Thrown and User-unhandled) are unchecked.

Now, the debugger should completely ignore a NUnit assertion failure (i.e. a thrown, caught or not, NUnit.Framework.AssertionException).

UPDATE: This will only prevent from breaking into the debugger, it cannot ignore the exception itself; i.e. it will not alter the actual program flow. Appart from changing or replacing or encapsulating the Assert-calls in try-catch blocks, I don't think there is anything that can achieve that (at least not automatically).

Answer 2

I'm uncertain if VS2010 Express has this option, but you can choose the exceptions to break on .

Go to the 'Debug' menu, then select 'Exceptions'

and from here you can select what exceptions to break on

Answer 3

I've ended up referencing nunit-gui-runner.dll and invoking it like

NUnit.Gui.AppEntry.Main(new string[] { Dll });

This brings up the NUnit gui. I can then run the specific test i'm interested in.

Answer 4

I had the same problem. Although your original approach (without the need for a try...catch block) works for most exception types, ArgumentNullException doesn't work. I fixed it like this:

[Test]
public void InstanciatingWithNullParameterThrowsException()
{
    bool isArgumentNullExceptionThrown = false;
    try
    {
       new CachedStreamingEnumerable<int>(null);
    }
    catch (ArgumentNullException)
    {
        isArgumentNullExceptionThrown = true;
    }
    Assert.That(isArgumentNullExceptionThrown);
}

It's not as elegant, but it does seem to work.