CODEWITHSUNDEEP
node.jsexpressmocha.jschaisupertest
Exluai
Exluai

Reputation: 23

Avoid using localhost to resolve tests in mocha

For some reason when I set my app in test.js like this:

const app = express();

I get a 404 error for all tests.

However, when I set it like this

const app = 'http://localhost:3000'

all tests pass.

I'm aware though that this is not the best way to declare app in a testing environment. how can I avoid using a fix path like localhost ?

example:

const express = require('express');
const app = express();
// const app = 'http://localhost:3000'
const chai = require("chai");
const expect = chai.expect;
const request = require('supertest');

  it('For all bookings', function (done) {
    request(app)
      .get('/bookings')
      .end(function (err, res) {
        expect('Content-Type', /json/)
        expect(res.statusCode).to.be.equal(200);
        done();
      });
  });

that way I get Uncaught AssertionError: expected 404 to equal 200

but if I uncomment const app = 'http://localhost:3000' to use it instead of const app = express(); then the test passes.

Upvotes: 2

Views: 626

Answers (2)

deerawan
deerawan

Reputation: 8443

if we did this in the test file

const app = express();

it means that we create brand new express application with no routes defined. The correct way is to use same express application not create a new one.

In order to do that, we can export the express app and refer it from the test file. 

// index.js
const express = require('express')
const app = express()
const port = 3000

app.get('/bookings', (req, res) => res.send('Hello World!'))

app.listen(port, () => console.log(`Example app listening on port ${port}!`))

module.exports = app; // export express app

Meanwhile for test file

// test.js

...

const app = require("./index"); // import the app

it("For all bookings", function(done) {
  request(app)
    .get("/bookings")
    .end(function(err, res) {
      console.log(res);
      expect("Content-Type", /json/);
      expect(res.statusCode).to.be.equal(200);
      done();
    });
});

Hope it helps

Upvotes: 1

Estus Flask
Estus Flask

Reputation: 223259

const app = express() creates dummy Express instance with no routes. It cannot respond to a request to /bookings endpoint because there's no such endpoint.

That http://localhost:3000 works means that an application that has has /bookings route is currently running.

In case application instance is provided to Supertest's request, an instance of the application that has /bookings route should be imported:

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

Upvotes: 1

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