Handling multiple asynchronous state updates in React 18 with useEffect and useState
I'm working on a React 18 project where I need to fetch data from multiple endpoints and update the local state based on the responses... I'm using `useEffect` to manage the fetching and `useState` to store the results. However, I'm encountering an issue where the state doesn't seem to update correctly when I receive responses in a non-deterministic order. Here’s a simplified version of what I have: ```javascript import React, { useEffect, useState } from 'react'; const MyComponent = () => { const [data, setData] = useState({ first: null, second: null }); useEffect(() => { const fetchData = async () => { const response1 = await fetch('https://api.example.com/endpoint1'); const data1 = await response1.json(); const response2 = await fetch('https://api.example.com/endpoint2'); const data2 = await response2.json(); // Update state with both responses setData({ first: data1, second: data2 }); }; fetchData(); }, []); return ( <div> <h1>Data from Endpoint 1</h1> <pre>{JSON.stringify(data.first, null, 2)}</pre> <h1>Data from Endpoint 2</h1> <pre>{JSON.stringify(data.second, null, 2)}</pre> </div> ); }; export default MyComponent; ``` The problem arises because the asynchronous nature of the fetch calls means that `data1` and `data2` might not be available in the order I expect. Sometimes, even though I see the correct data in the console, the UI does not update as expected, displaying stale values instead. I also tried using `Promise.all` to fetch both endpoints concurrently: ```javascript const fetchData = async () => { const [response1, response2] = await Promise.all([ fetch('https://api.example.com/endpoint1'), fetch('https://api.example.com/endpoint2') ]); const [data1, data2] = await Promise.all([ response1.json(), response2.json() ]); setData({ first: data1, second: data2 }); }; ``` This approach seems to make things slightly better, but I'm still experiencing issues with the state updates not reflecting immediately on the UI. Could this be due to React batching state updates? Is there a proper way to ensure that the UI reflects the latest state after asynchronous operations? Any insights or best practices for this scenario would be greatly appreciated. I'm working in a Ubuntu 20.04 environment. Any examples would be super helpful. The project is a microservice built with Javascript. How would you solve this?