Can query escape jest mocking ?

[hadson172]

So I was introducing react-query for one of big projects and I had this weird behaviour inside tests. My tests are using jest and rtl.

I have query fn which is function which calls "fetch" api and return promise. I was trying to mock this function in test. What surprise me is that when I run tests I was getting error "fetch is undefined". Its weird situation because like I said above I used jest to mock this function so it should not call real fetch API. I understand this may be to little information but my main question is - Is react query somehow is able to skip jest mocking and call directly real query fn ?

[louis-young]

Hi. Typically, you wouldn't mock the query function, but intercept the actual network request and mock the response using a tool like Mock Service Worker. The issue with fetch being undefined sounds like an issue with your test environment.

Dominik has written about this too: https://tkdodo.eu/blog/testing-react-query#mocking-network-requests