xUnit TheoryData class equivalent

[silkfire]

Is there any equivalent to strongly typed TheoryData<> classes in TUnit? This simplifies storing reusable data (IEnumerable<>) across test projects.

Note that I'm not asking about methods that return TheoryData but custom classes that inherit from it.

https://andrewlock.net/creating-strongly-typed-xunit-theory-test-data-with-theorydata/#strongly-typed-data-with-theorydata

[thomhurst]

You can create custom data generators by inheriting from DataSourceGeneratorAttribute<T>

These return back a collection of T's. So create this attribute in a common project. Then decorate your classes/test methods with it in various projects.

[silkfire]

Thanks! Is it possible to use this with matrices and not have to rely on [MatrixMethod(...)]?

[thomhurst]

You can generate the Ts however you want. So just plug in your logic to generate matrices, which most simply is just nested loops for all of your different parameter arguments

[silkfire]

I was hoping not to have to implement my own combinatorial (matrix) logic. Something to the likes of:

[Test]
[MatrixDataSource]
public async Task MyTest(
        [MatrixDataSourceGenerator<MyDataSourceGenerator1>] int value1,
        [MatrixDataSourceGenerator<MyDataSourceGenerator2>] int value2
        )
{
  ...
}

[thomhurst]

You'll have to implement it unfortunately, but the following code can do it:

private readonly IEnumerable<IEnumerable<object?>> _seed = [[]];

    private IEnumerable<IEnumerable<object?>> GetMatrixValues(IEnumerable<IReadOnlyList<object?>> elements)
    {
        return elements.Aggregate(_seed, (accumulator, enumerable)
            => accumulator.SelectMany(x => enumerable.Select(x.Append)));
    }

[silkfire]

Thanks for the example. Do you think something similar to my example could be implemented in the future?