Docs on creating extensions

[thomhurst]

This page shows what microsoft extensions are currently available: https://learn.microsoft.com/en-us/dotnet/core/testing/unit-testing-platform-extensions

But I cannot find a how-to on writing my own.

For example, I don't even know if this is possible with extensions, but I'd like to:

• Register an extension
• When my test suite finishes, my extension is passed information about that test suite
• That extension checks if we're running in GitHub actions
• If we are, it writes to the OUTPUT_SUMMARY file with an easy-to-read table of the results

[Youssef1313]

If I correctly understand what you need, I think what you need builder.TestHost.AddTestSessionLifetimeHandle(new YourExtension());

This will notify you when the test session ended. In addition, you can also implement IDataConsumer (and use builder.TestHost.AddDataConsumer) to get information on tests while they run so that you can accumulate this information at the end when you get the OnTestSessionFinishingAsync callback.

This is documented in https://learn.microsoft.com/en-us/dotnet/core/testing/unit-testing-platform-architecture-extensions#the-itesthostprocesslifetimehandler-extensions and https://learn.microsoft.com/en-us/dotnet/core/testing/unit-testing-platform-architecture-extensions#the-idataconsumer-extensions