How can I debug async hooks in Node.js?

How can I debug async hooks in Node.js?

Debugging async hooks in Node.js can be tricky. You can use the built-in async_hooks module to track asynchronous resources.

Can you give me an example of how to use the async_hooks module?

Sure! Here's a simple example:

const async_hooks = require('async_hooks');

const hook = async_hooks.createHook({
  init(asyncId, type, triggerAsyncId, resource) {
    console.log(`Init: ${asyncId} of type ${type}`);
  },
  before(asyncId) {
    console.log(`Before: ${asyncId}`);
  },
  after(asyncId) {
    console.log(`After: ${asyncId}`);
  },
  destroy(asyncId) {
    console.log(`Destroy: ${asyncId}`);
  }
});

hook.enable();

setTimeout(() => {
  console.log('Timeout executed');
}, 100);

What are some common pitfalls when using async hooks?

Common pitfalls include memory leaks due to untracked async resources and performance overhead from excessive logging. Always clean up resources!

Is there a way to visualize async hooks activity?

Yes, you can use tools like node --trace-async-hooks to visualize the async hooks activity in your application.