Use Moq to make mocking easier in Unit-Tests

[ramonB1996]

Hi,

I would love to know if Moq (https://github.com/moq/moq4) mocking library has ever been considered to be added to the Maui.CommunityToolkit?

If not, this would be the discussion section for this.

The problem: At the moment we have to create extra classes just to use them as a Mock, as far as my understanding goes.

All opinions welcome of course, I am willing to do some PR's for Unit tests and want to make it easier for myself and others if possible.

[bijington]

My opinion of Moq varies quite a bit. I have used it extensively in other projects and it has been great but later on I find it's usage results in more difficult to follow code/tests.

While on the topic of mocking I would like to advocate for making our current mocks more descriptive so rather than writing something like:

var mockConverter = new MockValueConverter(value => true);

We could modify it to something like:

var mockConverter = MockValueConverter.ThatReturns(true, for: value);

You don't easily get this readability from Moq but you could wrap it underneath.

Also I believe a number of our mocks have been lifted from the .NET MAUI repo.

That isn't me saying I'm against it but I don't see a big enough reason to do it. I am happy to be persuaded otherwise though 🙂

[VladislavAntonyuk]

I prefer NSubstitute. It has a much cleaner syntax. However, we decided to use Fake implementation to test without 3rd party libraries

[ramonB1996]

I understand your decision. I have 2 question then:

To test a class like UseCommunityToolkitAnalyzer, what would you do for these parts:

1. Input that the method Initialize() needs. How would you mock that away?
2. Check if certain methods were called or were not called? In Moq you can use verify() to check this.

I can live with the fact that we do not add this library, as it would increase package size as well. But I would love to know how to contribute to the unit-tests in these instances in a proper way.

[pictos]

@ramonB1996 testing Roslyn analyzer needs other methods, you can create a compilation with a string code and test if that works. You can find more examples on the Roslyn repo, since we need a workload in order to make it work that could be more tricky, to implement a unit test... If that looks hard, I would suggest to implement unit tests for our Source Generator, it will follow almost the same idea as the Analyzer unit test

[CliffAgius]

Closed as answered