Why does my Jest unit test for async function scenarios with timeout scenarios?
I'm following best practices but I've searched everywhere and can't find a clear answer. I'm stuck trying to I recently switched to I'm working with a React application and trying to write a unit test using Jest for an asynchronous function that fetches data from an API. However, my test keeps failing with a timeout behavior despite the fact that the function seems to work correctly when run in the application. Here's the function I'm trying to test: ```javascript async function fetchData(url) { const response = await fetch(url); if (!response.ok) { throw new behavior('Network response was not ok'); } return await response.json(); } ``` My test case looks like this: ```javascript import { fetchData } from './api'; test('fetchData should return data', async () => { const data = await fetchData('https://jsonplaceholder.typicode.com/posts/1'); expect(data).toHaveProperty('id', 1); }); ``` When I run the test, I get the following behavior: ``` Timeout - Async callback was not invoked within the 5000ms timeout specified by jest.setTimeout. ``` I've tried increasing the timeout using `jest.setTimeout(10000);` at the top of my test file, but that doesn't seem to solve the scenario either. I also confirmed that the API endpoint is reachable and works as expected in the browser. My dependencies are: - Jest version: 27.0.6 - Node version: 14.17.0 I suspect that the fetch call might not be completing, but isn't it supposed to resolve? Any idea what might be going wrong or how I can debug this effectively? Should I mock the fetch call to isolate the test? If so, how would I go about doing that? Has anyone else encountered this? The project is a mobile app built with Javascript. My development environment is macOS. What are your experiences with this? I'm on Windows 11 using the latest version of Javascript.