How to manage child process exit events in Node.js without losing data?
I'm trying to configure I can't seem to get I've looked through the documentation and I'm still confused about Quick question that's been bugging me - I'm currently working on a Node.js application that spawns child processes to handle heavy computation tasks using the built-in `child_process` module. The scenario arises when a child process exits; I want to capture its output and any errors before it terminates. However, I'm working with situations where the output data gets lost if the child process exits quickly. I've implemented the following code: ```javascript const { spawn } = require('child_process'); const child = spawn('node', ['heavyTask.js']); let outputData = ''; let errorData = ''; child.stdout.on('data', (data) => { outputData += data; }); child.stderr.on('data', (data) => { errorData += data; }); child.on('exit', (code) => { console.log(`Child process exited with code ${code}`); console.log(`Output: ${outputData}`); console.log(`Errors: ${errorData}`); }); ``` The question is that if `heavyTask.js` completes its execution very quickly, I sometimes end up with empty `outputData` or incomplete `errorData` when the `exit` event fires. I've tried adding a delay before logging the output, but that's not a reliable solution. I've also considered using the `process.on('message', ...)` method to communicate between the parent and child processes, but I'm unsure how to implement that correctly for handling outputs asynchronously. Is there a recommended way to ensure that I capture all output and errors reliably before the child process exits? Any best practices or patterns I might be missing? I'm using Node.js v16.13.0. This is part of a larger service I'm building. For context: I'm using Javascript on macOS. Could this be a known issue? My development environment is Debian. Any advice would be much appreciated. My team is using Javascript for this microservice. Any examples would be super helpful.