HTTP server adds `.on` override to sockets but not `.appendListener`

[Antonius-S]

• Version: v10.15.1 but affects master branch, v12 and so on
• Platform: W7
• Subsystem: HTTP server

Here HTTP server adds a .on wrapper to a socket. But no other listener methods are wrapped so if we call socket.addListener() or socket.prependListener() we'll get other results than if we called socket.on().

'use strict';

const http = require('http');

const srv = http.createServer();
srv.on('connection', (socket) => {
	console.log(socket.on === socket.addListener);
});

[SimonSchick]

Shouldn't this be used in this case?
https://nodejs.org/dist/latest-v11.x/docs/api/events.html#events_event_newlistener

[Antonius-S]

@SimonSchick this is probably really a proper way

[sam-github]

This looks to be an oversight/bug in the API to me, @nodejs/http ?

[GrosSacASac]

A future proof solution would be to iterate on all Event emitter methods, and do the assignement for each method name that is equal to on

[GrosSacASac]

Off topic:
Why do this :

Object.setPrototypeOf(ServerResponse.prototype, OutgoingMessage.prototype);
Object.setPrototypeOf(ServerResponse, OutgoingMessage); // ???

[Antonius-S]

A future proof solution would be to iterate on all Event emitter methods, and do the assignement for each method name that is equal to on

I don't think so. Mechanism of virtual functions is very nice in other languages but in JS it's a dirty and error-prone hack. Monkeypatching is acceptable for final objects but those in library are likely to be instantiated and extended. I'd vote for 'newlistener' listener

[GrosSacASac]

Yes, sorry I didn't see the replies

[himself65]

this bug caused by this code line

node/lib/_http_server.js

Line 396 in 290faec

socket.on = socketOnWrap;

when I try

srv.on('connection', (socket) => {
	console.log(socket.on)
	console.log(socket.addListener)
})

logged

[Function: socketOnWrap]
[Function]