How to exclude test case parameter from report in xUnit.net

[vchistov]

Assume we have the following test case:

[Theory]
[InlineAutoMoqData(1, "some result")]
public void DoWorkTest(Mock<MyService> myServiceMock, int paramX, string expectedResult)
{
    // test implementation
}

// where InlineAutoMoqData is kind of implementation of InlineAutoDataAttribute (AutoFixture.Xunit2)
// allowing to substitute mocked dependencies side-by-side with inlined test data

It will be cool to exclude myServiceMock from the allure report because it does not make sense. Does it possile? I found SkipAttribute (https://allurereport.org/docs/xunit-reference/#metadata), but it applicable for test step only.

[vchistov]

I've tried to implement something like this:

[AttributeUsage(AttributeTargets.Method)]
public class AllureExcludeParameterAttribute(string parameterName) : BeforeAfterTestAttribute
{
    public override void After(MethodInfo methodUnderTest)
    {
        AllureLifecycle.Instance.UpdateTestCase(tr =>
        {
            var parameter = tr.parameters.FirstOrDefault(p => p.name == parameterName);
            if (parameter != null)
            {
                tr.parameters.Remove(parameter);
            }
        });
    }
}

But it does not work because when After is calling the parameter "tr.parameters" still empty. It's going to be populated on TestFinished event: https://github.com/allure-framework/allure-csharp/blob/main/Allure.Xunit/AllureMessageSink.cs#L155

[delatrie]

Hi, @vchistov ! Unfortunately, this is not currently possible.

We will likely implement a way to preclude such parameters from the report in the future. We will also implement event listeners, which will help with such tasks, see allure-framework/allure-csharp#488. Unfortunately, I'm yet uncertain when exactly all these will be done.

The best you can do right now is to provide a custom formatter, which will serialize objects of certain types as, say, empty strings:

using Allure.Net.Commons;

class EmptyFormatter<T>: TypeFormatter<T>
{
    public override string Format(T value) => "";
}

Then the formatter should be registered somewhere once per each type. The easiest would be a module initializer:

using System.Runtime.CompilerServices;
using Allure.Net.Commons;

static class SetUp
{
    [ModuleInitializer]
    internal static void Initialize()
    {
        AllureLifecycle.Instance.AddTypeFormatter(new EmptyFormatter<Mock<MyService>>());
        AllureLifecycle.Instance.AddTypeFormatter(new EmptyFormatter<Mock<MyOtherService>>());
    }
}

Note, that will only work if the actual type of myServiceMock is exactly Mock<MyService>. If it's a subclass, you should adjust the formatter's type accordingly in Initialize.