How can I make a unit test run in DEBUG mode only?

Question

I have a unit test that tests if an Exception is throw, but this Exception is only throw in Debug mode (via the [Conditional("DEBUG")] Attribute). If I run this test in Release mode, it fails. I tried to apply the same Attribute on the test but it's no taken into account.

How can I exclude a test in Release mode? Does it even make sense to run unit tests in Release mode or should I stick to Debug mode?

Related: http://stackoverflow.com/questions/3133988/make-mstest-respect-conditional-attribute — Ohad Schneider, May 03 '16 at 14:32

score 17 · Accepted Answer · edited Jul 28 '16 at 12:03

17

As for most of your question, it depends somewhat on what unit testing tool your using. However, in general what you want are preprocessor directives

//C#
#ifndef DEBUG
    //Unit test
#endif

Perhaps for your situation

//C# - for NUnit
#if !DEBUG
    [Ignore("This test runs only in debug")] 
#endif

But as to whether to leave unit tests in the release version? I'd give a resounding NO. I'd suggest moving all your unit tests into it's own project and NOT including this in your releases.

edited Jul 28 '16 at 12:03

Kobi

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answered Oct 30 '09 at 11:26

C. Ross

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Of course, all my unit tests are in another project, but I can still run them in Release mode... – Julien Poulin Oct 30 '09 at 11:51
Why would you really want them to be different in release and debug? – C. Ross Oct 30 '09 at 12:36
I want to be sure that me code will behave the same in Debug and in Release mode. But in this particular case, I *know* that the test will fail in Release mode since the Exception should only be thrown in Debug mode (by design) – Julien Poulin Oct 30 '09 at 13:23
Well, I came up with a possible solution, provided your using NUnit. – C. Ross Oct 30 '09 at 13:49
I ended up using your solution after all. Since I'm using MSTest, the Attribute is [Ignore] (no parameter). – Julien Poulin Oct 30 '09 at 15:08
This is a better solution that works in every environment: http://stackoverflow.com/questions/5805464/are-there-nunit-test-case-attributes-for-specifying-configuration Just make a "DebugOnly" Category and exclude that from your Release build – Scott Oct 17 '12 at 17:24

score 7 · Answer 2 · answered Oct 30 '09 at 11:24

7

Try this:

#if DEBUG

// here is your test

#endif

answered Oct 30 '09 at 11:24

Stefan Steinegger

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This works but I think it's a too drastic solution. Instead, I used the [Ignore] Attribute (still, it's enclosed inside a #if !DEBUG ... #endif, but I like it better). – Julien Poulin Oct 30 '09 at 15:12

score 6 · Answer 3 · answered Oct 30 '09 at 11:25

6

If you're using NUnit, you can make your unit test methods conditional:

[System.Diagnostics.Conditional("DEBUG")]
public void UnitTestMethod()
{
   // Tests here
}

This way it will only be executed in DEBUG builds. I don't have a lot of experience with Visual Studio unit tests, but I'm pretty sure that this should work there in VS too.

EDIT: Others have mentionned conditional compilation directives. I don't think that it is a very good idea, for a number of reasons. To learn more about the differences between conditional compilation directives and the conditional attribute, read Eric Lippert's excellent article here.

answered Oct 30 '09 at 11:25

Tamas Czinege

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I'm using MSTest and it looks like the Conditional Attribute is not honored by the test engine... – Julien Poulin Oct 30 '09 at 12:01
You could put the conditional attribute on a DoUnitTestMethod helper method, which you would call from UnitTestMethod. This would then become an empty test that always passes in Release mode. Gets trickier with things like [ExpectedException] though. Simplest just to use #if DEBUG around the whole test case. – yoyo Jul 08 '14 at 23:44

score 5 · Answer 4 · answered Nov 09 '16 at 12:43

If you're using XUnit, you can use the following method as described by Jimmy Bogard by extending the fact attribute:

public class RunnableInDebugOnlyAttribute : FactAttribute
{
    public RunnableInDebugOnlyAttribute()
    {
        if (!Debugger.IsAttached)
        {
            Skip = "Only running in interactive mode.";
        }
    }
}

and then you can use this as follows:

[RunnableInDebugOnly]
public void Test_RunOnlyWhenDebugging()
{
    //your test code
}

score 1 · Answer 5 · answered Mar 20 '19 at 11:20

Similar solution for NUnit framework(only debugging test works):

public class DebugOnlyAttribute : NUnitAttribute, IApplyToTest
{

    private const string _reason = "Debug only";

    public void ApplyToTest(Test test)
    {
        if (!Debugger.IsAttached)
        {
            test.RunState = RunState.Ignored;
            test.Properties.Set(PropertyNames.SkipReason, _reason);
        }

    }
}

[DebugOnly]
[Test]
public void TestMethod()
{ 
//your test code
}

How can I make a unit test run in DEBUG mode only?

5 Answers5