Context lost in an unhandled exception (or rejection)

First of all - great module!

I was wondering if there’s any workaround to get the context, in case of an unhandled exception (or rejection, in case of promises). Here’s a sample code:

// cls.js
const cls = require('cls-hooked');
const clsNamespace = cls.createNamespace(process.getuid());

module.exports = {
  middleware: (req, res, next) => {
    run(() => {
      let someContextId = getTheIDSomehow();
      set('context-id', someContextId)
      next()
    }),
  ns: clsNamespace
}

// some-other-file.js
const ns = require('./cls').ns;

process.on('unhandledRejection', () => {
  // this will be undefined
  console.log(ns.get('context-id')); 
});

[wesleytodd]

I would strongly recommend against this module (express-async-errors). Reaching deeply into the router like this is a bad idea, it will also not work in v5. The behavior you want is already added in v5 (https://github.com/pillarjs/router/pull/47 & https://github.com/pillarjs/router/commit/d2bce0c09d424ea89e77cef7743e12f411ed94f7).

In express v4, a much better approach is to use something like https://github.com/express-promise-router/express-promise-router

All that said, this is a bit off topic for this issue which is specifically about usage of this module.

[zhujun24]

I have write a tidy npm package http-request-context to do this, using async_hooks, u can try it.