implementing Testing a React Component that Uses Context API and Async State Updates
I'm confused about I'm converting an old project and I tried several approaches but none seem to work. I'm having trouble testing a React component that consumes a context API and performs async state updates. My component looks like this: ```javascript import React, { useContext, useEffect } from 'react'; import { MyContext } from './MyContext'; const MyComponent = () => { const { data, fetchData } = useContext(MyContext); useEffect(() => { fetchData(); }, [fetchData]); if (!data) return <div>Loading...</div>; return <div>{data}</div>; }; export default MyComponent; ``` I'm using Jest and React Testing Library for my tests. I wrote a test that attempts to verify that the loading state is displayed initially and then shows the data once it's available. However, I'm running into a question where my test fails because the state doesn't update in time. Here's the test I wrote: ```javascript import React from 'react'; import { render, screen, waitFor } from '@testing-library/react'; import MyComponent from './MyComponent'; import { MyContext } from './MyContext'; jest.mock('./MyContext', () => ({ MyContext: React.createContext(), })); test('displays loading and then data', async () => { const mockFetchData = jest.fn().mockImplementation(() => { return new Promise(resolve => setTimeout(() => resolve('Hello World'), 1000)); }); render( <MyContext.Provider value={{ data: null, fetchData: mockFetchData }}> <MyComponent /> </MyContext.Provider> ); expect(screen.getByText(/loading/i)).toBeInTheDocument(); await waitFor(() => expect(mockFetchData).toHaveBeenCalled()); // Here is where it fails expect(screen.getByText('Hello World')).toBeInTheDocument(); }); ``` The behavior message I get is `Unable to find an element with the text: Hello World`. I can see that `mockFetchData` is being called, but the component never updates to show the data. I suspect it might have something to do with the fact that I've mocked the context, but I need to figure out how to resolve this. Any guidance on how to correctly test this scenario would be greatly appreciated. I'm using React 17 and Jest 26. For context: I'm using Javascript on macOS. What am I doing wrong? I'd really appreciate any guidance on this. Thanks for taking the time to read this! The project is a CLI tool built with Javascript. I'd really appreciate any guidance on this.