implementing Jest and React Testing Library not triggering useEffect on state change
I've been banging my head against this for hours..... I'm upgrading from an older version and Does anyone know how to I've been banging my head against this for hours. I've searched everywhere and can't find a clear answer. I'm having trouble with my tests not accurately reflecting the behavior of a component that relies on `useEffect` when state changes. I'm using React 17.0.2 along with Jest 27.2.5 and React Testing Library 12.0.0. My component is supposed to fetch data when a button is clicked, and I expected the `useEffect` that watches a state variable to run accordingly. Here's a simplified version of my component: ```javascript import React, { useEffect, useState } from 'react'; const FetchDataComponent = () => { const [data, setData] = useState(null); const [fetchData, setFetchData] = useState(false); useEffect(() => { if (fetchData) { fetch('https://api.example.com/data') .then(response => response.json()) .then(json => setData(json)); } }, [fetchData]); return ( <div> <button onClick={() => setFetchData(true)}>Fetch Data</button> {data && <div>{JSON.stringify(data)}</div>} </div> ); }; export default FetchDataComponent; ``` In my test, I'm simulating a button click, but it seems like the `useEffect` is not being triggered. Here's what my test looks like: ```javascript import { render, screen, fireEvent, waitFor } from '@testing-library/react'; import FetchDataComponent from './FetchDataComponent'; test('fetches and displays data on button click', async () => { render(<FetchDataComponent />); fireEvent.click(screen.getByText(/fetch data/i)); // Wait for the data to appear const dataElement = await screen.findByText(/some expected data/i); expect(dataElement).toBeInTheDocument(); }); ``` However, I keep getting the behavior: `Unable to find an element with the text: some expected data`. I've tried using `waitFor` and `findByText`, but it doesn't seem to wait for the `useEffect` to complete before checking for the data. I've also verified that the API returns the expected data when called in the browser. Am I missing something in how Iām setting up the test or handling the async behavior? Any advice would be greatly appreciated! I'd really appreciate any guidance on this. This issue appeared after updating to Javascript 3.9. What am I doing wrong? I'd really appreciate any guidance on this. The stack includes Javascript and several other technologies. Cheers for any assistance! I'm working in a Ubuntu 22.04 environment. What are your experiences with this?