res.end should finish response

[mctep]

Hello. Thanks for your job.

I have some code in express:

var express = require('express');
var session = require('express-session');
var request = require('supertest');

var app = express();

app.use(session({
    resave: true,
    saveUninitialized: true,
    secret: 'test'
}));

app.get('/',
    function(req, res, next) {
        var someBigIsolateLogic = true;
        if (someBigIsolateLogic) {
            res.send('I have some result');
        }

        // I don't know about big logic
        // and what it have to send or not send.
        // 
        // I have to send default content.
        if (!res.finished) {
            res.send('Default result');
        }
    }
);

request(app).get('/').expect(200).end(function() {});

In some places I rely on the res.finished to find out whether the response has finished. And if it has not, I send the default result.

But the code above throws the Error('Can't set headers after they are sent.') because the original req.end is called asynchronously, and it doesn't set the req.finished as true at the right time. And without using session this code works as expected.

My PR resolves this problem, and I think it looks like hack. But I worked out nothing better.

[dougwilson]

This may be reasonable, but your change has some edge cases. I can fix them and get something in this week.

[dougwilson]

In the meantime, you should change your code, as it's currently broken. Your code should be checking http://nodejs.org/api/http.html#http_response_headerssent (res.headersSent) before setting headers, because res.finished is false even when you're not allowed to set headers any more, regardless of this module. This module just brought that bug in your code to light.

[mctep]

Oh, yes. You are absolutely right. Thank you so much.
I think my PR is unuseful. So I close it.