How to implement custom NUnit attribute based on TestCaseSourceAttribute?

[czarls]

Hi all, I have been using Reqnroll for some time now along with my other C# test projects. I want to share some functionalities between them. In my other NUnit project I use custom TestCaseParams attribute implementing TestCaseSourceAttribute:

[AttributeUsage(AttributeTargets.Method, AllowMultiple = true, Inherited = false)]
public class TestCaseParamsAttribute : TestCaseSourceAttribute
{
    public TestCaseParamsAttribute(int testCaseId)
        : base(typeof(DataProviders), nameof(DataProviders.GetParamObjects), new object[] { testCaseId })
    {
    }
}

GetParamObjects method, which takes argument testCaseId returns an array of objects which create me test parameters (in this case it retrieves Azure Test Case parameters - shared or local).

I'm wondering how to implement a new, custom plugin in Reqnroll, which creates me Scenario Outline after build, similarly to "External Data Plugin".

Perfect solution would be a tag: @DataSourceFromTestCase:{int}

Thanks! :)

[clrudolphi]

You might try the Decorators feature in a custom Generator PlugIn:
https://docs.reqnroll.net/latest/extend/decorators.html

Or you might try extending the External Data Plugin by creating a new IDataSourceLoader.

[czarls]

@clrudolphi thanks, Decorators with a custom Generator Plugin is what I tried but I stucked on Generator Plugin, couldn't also find any working example in Reqnroll examples, nor in Specflow (at least the one targeting .NET 6 or above).
Extending External Data Plugin is far too much now ;)
Do you know if there is any working example of custom Generator Plugin, with the feature file also to have the full flow?

[clrudolphi]

I'm not aware of any generator samples. The External Data plugin is the best available example for you to work from.

[gasparnagy]

@czarls When I cleaned up the pages https://docs.reqnroll.net/latest/extend/plugins.html#generator-plugins and https://docs.reqnroll.net/latest/extend/decorators.html, I think I have tried them out to create a generator plugin. Could you please give another try?

[czarls]

Hi @gasparnagy, yep, I went through those pages in the documentation. Decorators is clear for me however I have a feeling that Generator Plugin is missing something - that's what I understood at least from the Specflow's project code. I think I would fully understand this when having some working example - even the one from documentation.
Parts I don't get is the *.nuspec file and *.csproj configuration.
Generator Plugin and Decorator classes are clear to me.
However, it's still not working, [NUnit.Framework.CategoryAttribute("myMethodTagDecorator")] is being created in generated *.feature.cs file instead of ApartmentAttribute.

[gasparnagy]

I haven't really found the right place for it, but I added a simple generator plugin that uses the decorator from the docs to https://github.com/reqnroll/Reqnroll.ExploratoryTestProjects/tree/main/CustomPlugins

It also contain a test project and it works, please check the note in the readme.