Is there a way to mock what a thrown exception in the try catch block? I want to test my function that the url string in error.message is indeed replaced with replacedURL string. How can I easily test it or mock the thrown exception to an object with this URL.
async function getUsers() {
try {
const response = await fetch('/api/users');
if (response.status >= 400) {
console.error('Could not fetch users');
return;
}
const users = response.json();
return users;
} catch (error) {
let message = error.message;
if (message) {
message = message.replace(/https:\/\/some.url.com /g, 'replacedURL');
delete error.message;
}
console.error('error', error);
}
}
Here's my test
test('url in error message is replaced', () => {
expect(getUsers()).toThrow('replacedURL');
})
You might want to actually throw an error in your function for it to be caught by toThrow.
Also, I'd recommend that your test doesn't actually tries fetching from the API (unless you're sure that's what you want it to do). Instead, consider using a custom caller (which can extend fetch) which you can then mock the response for, like const caller = jest.fn().mockRejectedValue({ message: 'https:://some.url.com' });