bindEmitter after context.exit should work?

[iliakan]

If the code uses bindEmitter, and the emitter triggers after context.exit(), should the emitter work?

For example, the code:

app.use(function*(next) {
    var context = ns.createContext();
    ns.enter(context);

    ns.bindEmitter(this.req);
    ns.bindEmitter(this.res);

    try {
      ns.set('context', this);
      yield* next;
    } finally {
      ns.exit(context);
    }
  });

If this.res emits an event after ns.exit, this event will normally be handled in the context?

I'm asking that, because it must really help to track dead ends in the app. Must know whether this should work or not.

[overlookmotel]

My understanding is that the context should still be available in next after you've called ns.exit() (I could be wrong though).

I think the code you provided may malfunction, though, because of the use of yield. yield pauses the execution so ns.exit() doesn't get called synchronously. But then while the promise returned by next() is waiting to resolve, other code from other requests will run. So that code will run before ns.exit() and so may get the wrong context.

Again, I'm not 100% sure about this, but I think you may be asking for trouble mixing yield with CLS.

I think this may work more reliably:

app.use( function*(next) {
    var promise;
    ns.run( function() {
        ns.bindEmitter(this.req);
        ns.bindEmitter(this.res);
        ns.set('context', this);

        promise = next();
    }.bind(this) );
    yield promise;
} );

I assume the code you provided is koa middleware, right?