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Promise.reject() expects a callback instead of an error (for testing .rejects) #4755
Description
What version of Bun is running?
1.0.0+822a00c4d508b54f650933a73ca5f4a3af9a7983
What platform is your computer?
Darwin 22.4.0 arm64 arm
What steps can reproduce the bug?
Write the Jest .rejects test example:
test('rejects to octopus', () => {
// make sure to add a return statement
return expect(Promise.reject(new Error('octopus'))).rejects.toThrow(
'octopus',
);
});Run bun test
What is the expected behavior?
The test passes with a ✓ rejects to octopus
What do you see instead?
The test fails with this message:
error: Expected value must be a function
✗ remove > rejects to octopus [0.69ms]Additional information
From the error message it seems the expect() wants a function instead of a promise, but expect(() => Promise.reject(new Error("octopus"))) also doesn't work (Expected promise\nReceived: [Function]).
After some more testing it seems it's Promise.reject() the one with a problem:
// Works (notice function in the reject):
const rejecting = Promise.reject(() => new Error("octopus"));
return expect(rejecting).rejects.toThrow("octopus");
// Doesn't work (notice no function):
const rejecting = Promise.reject(new Error("octopus"));
return expect(rejecting).rejects.toThrow("octopus");However according to MDN, the correct syntax should be the one without the callback, not the one with the callback:
Promise.reject(new Error('fail'))Reacted by Bjön Limell, Eugene, Nico Mürdter, Julius Foitzik, Luke Childs, Luna, Nikita Karpukhin, Raphael Oliveira, Anderson Joseph, Christian Rishøj and 2 more
Activity
[-]expect().rejects doesn't work with Jest example[/-][+]Promise.rejects() expects a callback instead of an error (for testing `.rejects`)[/+][-]Promise.rejects() expects a callback instead of an error (for testing `.rejects`)[/-][+]Promise.reject() expects a callback instead of an error (for testing `.rejects`)[/+]franciscop commentedon Sep 15, 2023
Confirmed as still happening in Bun 1.0.2
nektro commentedon May 24, 2024
does this still reproduce for you? it appears to be working on my end in Bun 1.1.9 (you may need to run
bun upgrade)franciscop commentedon May 25, 2024
I can confirm this works now! A rejected promise works properly and as expected in JS:
And the default example I put above works. Thanks for fixing this!