I very much agree with you on this. Upgrading dependencies is something you do and you are responsible for if it broke things. I'd frame it slightly differently

I very much agree with you on this. Upgrading dependencies is something you do and you are responsible for if it broke things. I'd frame it slightly differently though. I think you should have some tests that tests the full functionality the user will experience, regardless where the pieces come from. And don't go our of your way to mock or stub something because it's not written by you. There is no reason to avoid useState() being executed in your test suite as long as your code actually depends on it and your test doesn't get super expensive to execute or write because of it. Now, if something is expensive, try to limit testing it only to the top of your testing pyramid. But you should till test the full stack because that's what you are gonna ship!