Testing a React Component with Context API and Handling Asynchronous State Updates
After trying multiple solutions online, I still can't figure this out... This might be a silly question, but I'm currently working on unit tests for a React component that consumes a context API for state management. The component fetches data asynchronously and updates the context state accordingly. However, I'm working with an scenario where the test fails because the component doesn't seem to reflect the updated state after the asynchronous action completes. Here’s a simplified version of my component: ```javascript import React, { useContext, useEffect } from 'react'; import { MyContext } from './MyContext'; const MyComponent = () => { const { data, fetchData } = useContext(MyContext); useEffect(() => { fetchData(); }, []); return <div>{data ? data.message : 'Loading...'}</div>; }; export default MyComponent; ``` In my test file, I’m using React Testing Library. Here’s how I'm trying to test it: ```javascript import { render, screen, waitFor } from '@testing-library/react'; import MyComponent from './MyComponent'; import { MyContextProvider } from './MyContext'; test('displays fetched data', async () => { render( <MyContextProvider> <MyComponent /> </MyContextProvider> ); await waitFor(() => { expect(screen.getByText(/Loading.../)).toBeInTheDocument(); }); // Assume fetchData updates the context with { message: 'Hello World' } expect(await screen.findByText(/Hello World/)).toBeInTheDocument(); }); ``` However, when I run this test, I get the following behavior: `behavior: Unable to find an element with the text: Hello World`. I suspect that the context state isn’t updating correctly or that the asynchronous fetch isn’t completing before the test checks for the expected output. I've verified that `fetchData` is correctly updating the context state and that the `MyContextProvider` is set up properly. Additionally, I am using React Testing Library version 12.0.0 and React version 17.0.2. Can anyone guide to understand how to correctly test this scenario? Am I missing something in how I handle asynchronous state updates in my tests? I'm working on a API that needs to handle this. Is there a better approach?