Inconsistent Results When Using Array Filter with Async Function in JavaScript
I'm updating my dependencies and Hey everyone, I'm running into an issue that's driving me crazy... I'm relatively new to this, so bear with me. After trying multiple solutions online, I still can't figure this out. I'm encountering an issue when trying to filter an array of objects using an async function. The expectation is to return only those objects that meet certain criteria based on an asynchronous check, but I'm getting inconsistent results. Here’s a simplified version of what I've tried: ```javascript const data = [ { id: 1, name: 'John' }, { id: 2, name: 'Jane' }, { id: 3, name: 'Doe' } ]; const isValid = async (item) => { // Simulating an asynchronous check, e.g., a database call return new Promise((resolve) => { setTimeout(() => { resolve(item.id % 2 === 0); }, 100); }); }; const filterData = async () => { const results = await Promise.all(data.map(async (item) => { const valid = await isValid(item); return valid ? item : null; })); return results.filter(Boolean); }; filterData().then(result => console.log(result)); ``` When I run this code, I occasionally get an empty array or an array with nulls, depending on how the promises resolve. I expected the output to be an array containing only the object with an even `id`, but the results seem random. I've ensured that the `isValid` function resolves correctly, and I am using `Promise.all` to handle all promises. I suspect it might be related to how I'm filtering out the null values after awaiting the promises. Is there a more reliable way to perform this filter operation with async functions? Also, could there be any issues related to the execution order of the async calls? I'm using Node.js v14.17.0. Any insights or suggestions would be greatly appreciated! This is part of a larger CLI tool I'm building. Has anyone else encountered this? My development environment is Linux. Has anyone else encountered this? I'm using Javascript 3.10 in this project. I'd be grateful for any help. My team is using Javascript for this CLI tool. What would be the recommended way to handle this?