implementing Mocking Axios in React Testing Library for Asynchronous Data Fetching
I'm building a feature where I'm migrating some code and This might be a silly question, but I'm working with an scenario while trying to test a React component that fetches data using Axios... The component renders a loading spinner initially, then displays the data once it has been fetched. I'm using React Testing Library and Jest for testing. The question arises when the fetch call is mocked; for some reason, the component does not update properly after the mock resolves. Here's the relevant part of my component: ```javascript import React, { useEffect, useState } from 'react'; import axios from 'axios'; const DataDisplay = () => { const [data, setData] = useState(null); const [loading, setLoading] = useState(true); useEffect(() => { const fetchData = async () => { const result = await axios.get('https://api.example.com/data'); setData(result.data); setLoading(false); }; fetchData(); }, []); if (loading) return <div>Loading...</div>; return <div>{JSON.stringify(data)}</div>; }; export default DataDisplay; ``` In my test file, I have the following code: ```javascript import React from 'react'; import { render, screen, waitFor } from '@testing-library/react'; import axios from 'axios'; import DataDisplay from './DataDisplay'; jest.mock('axios'); test('displays data after fetch', async () => { const mockData = { title: 'Test Data' }; axios.get.mockResolvedValueOnce({ data: mockData }); render(<DataDisplay />); expect(screen.getByText(/loading/i)).toBeInTheDocument(); await waitFor(() => { expect(screen.getByText(/Test Data/)).toBeInTheDocument(); }); }); ``` However, when I run the test, it fails with the behavior message: `Unable to find an element with the text: Test Data`. I've tried using `jest.clearAllMocks()` in the `beforeEach` section, but it didn't help. I also ensured that the mock is set up correctly and that there are no spelling mistakes in the data. What am I missing here? Is there something specific about using Axios with React Testing Library that I should be aware of? Any help would be appreciated! This is part of a larger web app I'm building. I'd really appreciate any guidance on this. This is my first time working with Javascript stable. Am I approaching this the right way? The project is a web app built with Javascript. Am I missing something obvious?