"disconnect" event on the "request" object is never emitted

[jfromaniello]

This is a simple test where I create a HAPI server with a route that replies with "hello world" after 2 seconds. The same code contains a client that does a request to the route and aborts it after 500ms.

const request = require('request');
const Hapi = require('hapi');

const server = new Hapi.Server();

server.connection({
  host: 'localhost',
  port: 3001,
});

server.route({
  method: 'GET',
  path:'/slow',
  handler: function (request, reply) {
    request.once('disconnect', () => {
      console.log('disconnected');
    });
    setTimeout(() => reply('hello world'), 2000);
  }
});

server.start();

setTimeout(() => {
  console.log('starting request');
  const req = request.get('http://localhost:3001/slow');
  setTimeout(() => {
    console.log('aborting request');
    req.abort();
  }, 500);
}, 1000);

According to the documentation the request object should emit a disconnect event. After debugging for a while I notice that HAPI subscribes to the event too late when the route calls the reply function.

I have tried with version hapi@16.4.3 and node v6.

Thank you very much in advance.

[AJamesPhillips]

I tried to recreate this and succeeded. I also tried using the python requests with requests.get("http://localhost:3001/slow", timeout=1) and using net as per the hapi tests.

What are you trying to achieve or the steps to reproduce?

// https://github.com/hapijs/hapi/issues/3528

// const request_module = require('request');
const Hapi = require('hapi');
const Net = require('net');

const server = new Hapi.Server();

server.connection({
  host: 'localhost',
  port: 3001,
});

const onRequest = function (request, reply) {

    request.once('disconnect', () => {

        console.log('server: request disconnected');
    });

    request.once('finish', () => {

        console.log("server: request finished");
    });

    return reply.continue();
};

server.ext('onRequest', onRequest);

server.route({
    method: 'GET',
    path: '/slow',
    handler: function (request, reply) {

        console.log("server: handling request");

        setTimeout(() => {

            console.log("server: replying");
            reply('hello world');
        }, 200);
    }
});

server.start((err) => {

    if (err) {
        console.error('server: error', err);
        process.exit(1);
    }

    console.log('server: started');

    const client = Net.connect(3001, 'localhost', () => {

        console.log('client: starting request');
        client.write('GET /slow HTTP/1.1\r\n\r\n');
        console.log('client: starting request');
        client.write('GET /slow HTTP/1.1\r\n\r\n');
    });

    client.on('data', (data) => {

        console.log('client: received data:', data);
    });

    setTimeout(() => {

        console.log('client: destroying client');
        client.destroy();
    }, 100);
});

What was the result you received?

server: started
client: starting request
client: starting request
server: handling request
server: handling request
client: destroying client
server: replying  # <=
server: replying  # <=

What did you expect?

server: started
client: starting request
client: starting request
server: handling request
server: handling request
client: destroying client
server: request disconnected  # <=
server: request disconnected  # <=

[devinivy]

This does appear to be a bug to me. The request's close/abort listeners aren't added until transmission:

hapi/lib/transmit.js

Lines 269 to 290 in c212bc8

	if (event || err) {
	request.emit('disconnect');
	}
	request._log(tags, err);
	return callback();
	};
	source.once('error', end);
	const onAborted = () => {
	return end(null, 'aborted');
	};
	const onClose = () => {
	return end(null, 'close');
	};
	request.raw.req.once('aborted', onAborted);
	request.raw.req.once('close', onClose);

The current hapi test doesn't cause the disconnect until transmission has begun:

hapi/test/request.js

Lines 334 to 338 in b8efbd9

	client.on('data', () => {
	--total;
	client.destroy();
	});

It seems that the close/abort listeners that trigger the disconnect event should be moved roughly here:

hapi/lib/request.js

Lines 171 to 178 in b8efbd9

	this._onClose = () => {
	this._log(['request', 'closed', 'error']);
	this._isPayloadPending = false;
	this._isBailed = true;
	};
	this.raw.req.once('close', this._onClose);

[jfromaniello]

Thanks a lot!