Uncaught Error: ECONNREFUSED: Connection refused

So I’m writing some tests using Mocha, chai and supertest.

I’m facing a really weird behavior here on a test that should work just fine. Here’s the test code:

var app = require('../app/app');
var agent = request.agent(app);

process.env.NODE_TLS_REJECT_UNAUTHORIZED = '0';

//Run request tests
describe('Request Tests - Setting Enviroment', () => {


    before((done) => {
        //set TEST env
        process.env.TEST = true;
        //load app
        app.start().then(() => {
            done();
        });
    });

    describe('basic page request', () => {
    
        it('should respond with 200 respond code', () => {

            request(app).get('/login')
            .expect(200)
            .expect('Content-Type', 'text/html; charset=utf-8')
            .end((err, res) => {
                if (err) throw err;
            });

        });

    });

    //Server ready
    describe('Fuzz Test', () => {

        describe('fuzzing login page with 1000 username/password permutations', () => {

            fuzzer.seed(0);

            it('should respond with 403 / invalid csrf token', () => {

                for(var i=0; i <= 1000; i++){

                    request(app).post('/login')
                    .send({
                        username: fuzzer.mutate.string('fuzzfromhere'),
                        password: fuzzer.mutate.string('fuzzfromhere')
                    })
                    .expect((code) => {
                        if (code != 403 && code != 429) throw code;
                    })
                    .end((err, res) => {
                        if (err) throw err;
                    });

                }

            });

        });

        describe('fuzzing tokenizer page with 1000 random values', () => {

            it('should respond with response from External API or invalid value', () => {
                // touch env to skip login and rate limiter
                process.env.TEST = 'skipLogin,skipRateLimiter';
                //get csrf to validate queries
                request(app).get('/tokenize')
                .expect((response) => {
                    console.log(`expect resp: ${response}`);
                })
                .end((err, res) => {
                    if (err) throw err;
                    console.error(`expect error: ${err}`);
                });
            });

        });
    
    });

    //Tests completed, end server
    after((done) => {
        app.end().then(() => {
            delete process.env.TEST;
            done();
        }).catch((err) => {
            throw err;
        });

    });

});

For some weird reason, I am getting the following error:

    Request Tests - Setting Enviroment
    Fuzz Test
    fuzzing tokenizer page with 1000 random cards
    should respond with response from Key Manager or invalid number:
    Uncaught Error: ECONNREFUSED: Connection refused
    at Test.assert (node_modules\supertest\lib\test.js:165:15)
    at assert (node_modules\supertest\lib\test.js:131:12)
    at C:\Users...\src\node_modules\supertest\lib\test.js:128:5
    at Test.Request.callback (node_modules\superagent\lib\node\index.js:718:3)
    at ClientRequest.req.once.err (node_modules\superagent\lib\node\index.js:646:10)
    at TLSSocket.socketErrorListener (_http_client.js:387:9)
    at emitErrorNT (internal/streams/destroy.js:64:8)
    at _combinedTickCallback (internal/process/next_tick.js:138:11)
    at process._tickCallback (internal/process/next_tick.js:180:9)

Any idea what’s causing this?

[sabyanna]

I had the same error message, my bug was an incorrect url, i forgot the ‘/’ at the beginning of the url.

[vlad-at-work]

Is it possible supertest to be the cause of the issue?

Error: ECONNREFUSED: Connection refused

Reproduce

• Mac OS 10.15.7
• node 18.3.0
• chai@4.3.6
• supertest@6.2.3

var request = require('supertest');
var { expect } = require('chai');

var api = request('http://127.0.0.1:4000'); // <-- works
var api = request('http://localhost:4000'); // <-- does not work

…

$ curl http://127.0.0.1:4000/home Welcome Home

What I found was that you have to import express app and pass it to request(app) like so, otherwise you’d get the ECONN problem. I’m not totally sure why this is but I hope this helps someone.

Also, don’t forget to then return the result of the (likely await) in the test function or else the test suite will complain at you: either return the promise or have a done(). Such were my meager findings.