Testing · Junior · Question 25 of 78

How do you check that a promise rejects?

✓Correct answer: await expect(fetchUser(-1)).rejects.toThrow("Not found")
2expect(fetchUser(-1)).toThrow("Not found")
3expect(await fetchUser(-1)).toBeUndefined()

Explanation

.resolves/.rejects unwrap the promise. Don't forget await (or return), otherwise the assertion isn't awaited.

Further reading

Jest: Testing Asynchronous Code ↗

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