Express.js, Jest, Supertest: Trouble with test runner finding a route handler

Question

I'm trying to setup tests on an Express server using Jest and Supertest. Here is my test and target code:

// routes/index.js
var express = require('express');
var router = express.Router();

router.get('/', function(req, res, next) {
  res.render('index', { title: 'Express' });
});



// index.test.js
const request = require('supertest');
const express = require('express');

const app = require('express');
const router = require('../index').router;


test('GET /', (done) => {
  request(router)
    .get('http://localhost:4000')
    // .set('Accept', 'application/json')
    .expect(200)
    .end((err, res) => {
      if (err) throw err;
      done();
    })
});

Jest is giving me the following error:

expected 200 "OK", got 404 "Not Found"

      at Test.Object.<anonymous>.Test._assertStatus (node_modules/supertest/lib/test.js:268:12)
      at Test.Object.<anonymous>.Test._assertFunction (node_modules/supertest/lib/test.js:283:11)
      at Test.Object.<anonymous>.Test.assert (node_modules/supertest/lib/test.js:173:18)
      at Server.localAssert (node_modules/supertest/lib/test.js:131:12)

Also tried: Relative urls ('/'). Error: Can not read property "apply" of undefined

Importing the router object exported in routes/index.js like so:

const router = require('../index').router;  
// TypeError: Cannot read property 'address' of undefined 
// (while pointing at the .get() method)

I suspect the way I'm bringing in Router() may not be right but my direct attempt didn't succeed.

Anyone have an idea of the issue?

Answer 1

Solved by requiring app.js and passing it to request like so:

const app = require("../../app");

test('GET /cold-start', (done) => {
  request(app)
    .get('/')
    .set('Accept', 'application/json')
    .expect(200)
    .end((err, res) => {
      if (err) throw err;
      done();
    })
});