advanced patterns with Promise.allSettled in React Component - Handling State Updates
Could someone explain Quick question that's been bugging me - This might be a silly question, but I'm using `Promise.allSettled` to manage multiple API requests in a React component, but I'm working with unexpected behavior where the state isn't updating as I intend. I'm using React 18 and Axios for my API calls. My goal is to fetch data from three different endpoints and update the state with the results, whether they succeed or unexpected result. Here's a snippet of the code I'm working with: ```javascript import React, { useState, useEffect } from 'react'; import axios from 'axios'; const MyComponent = () => { const [data, setData] = useState([]); const [errors, setErrors] = useState([]); useEffect(() => { const fetchData = async () => { const requests = [ axios.get('https://api.example.com/data1'), axios.get('https://api.example.com/data2'), axios.get('https://api.example.com/data3') ]; const results = await Promise.allSettled(requests); const newData = results.map(result => { if (result.status === 'fulfilled') { return result.value.data; } else { setErrors(prevErrors => [...prevErrors, result.reason]); return null; } }).filter(Boolean); setData(newData); }; fetchData(); }, []); return ( <div> <h1>Data</h1> <ul> {data.map((item, index) => <li key={index}>{item.name}</li>) } </ul> {errors.length > 0 && <div>Errors: {errors.join(', ')}</div>} </div> ); }; export default MyComponent; ``` I've noticed that when one of the requests fails, the behavior message gets logged, but the state for `data` ends up being an empty array even though the successful requests should populate it. I've tried checking the network requests in the browser and verified that the API calls return the expected results, but it seems like the state isn't updating correctly after the `Promise.allSettled` resolution. I'm unsure if I'm handling state updates incorrectly or if there's a timing scenario with the asynchronous nature of `useEffect` and state updates. Any insights on why the `data` state isn't reflecting the successful API results would be greatly appreciated! This is part of a larger API I'm building. Am I missing something obvious? Has anyone else encountered this? I recently upgraded to Javascript latest.