Mocha does not run tests defined within a function

[AbdelrahmanHafez]

Prerequisites

• [x] Checked that your issue hasn't already been filed by cross-referencing issues with the faq label
• [x] Checked next-gen ES issues and syntax problems by using the same environment and/or transpiler configuration without Mocha to ensure it isn't just a feature that actually isn't supported in the environment in question or a bug in your code.
• [x] 'Smoke tested' the code to be tested by running it outside the real test suite to get a better sense of whether the problem is in the code under test, your usage of Mocha, or Mocha itself
• [x] Ensured that there is no discrepancy between the locally and globally installed versions of Mocha. You can find them with: node node_modules/.bin/mocha --version(Local) and mocha --version(Global). We recommend avoiding the use of globally installed Mocha.

Description

I am trying to test my API with mocha & superagent, the thing is, I need to wait for the db to open, then export the app, because the tests require some initialization code that depends on the db.

So, in order to do that, I had to wrap my test code within an async function and call it, but it doesn't run the tests.

// test.js

describe('math', async () => {
  it('multiplies', () => {
    let result = 2 * 2;
    result.should.equal(4);
  });
});

const test = async () => {
  const should = require('chai').should();
  const request = require('supertest');
  const path = require('path')
  const app = await require(path.resolve('./server'));

  describe('math', async () => {
    it('adds', () => {
      let sum = 1 + 1;
      sum.should.equal(2);
    });
  });

  describe('users', async () => {
    it('creates a customer', async () => {
      let res = await request(app).get('/api/should-404/');
      res.status.should.equal(200);
    });
  });
};

test().catch(console.err);

// server.js

const run = async () => {
  const app = express()();
  const mongoose = require('mongoose');
  await mongoose.connect('mongodb://localhost:27017/speero_test');

  const db = mongoose.connection;

  db.on('error', console.error.bind(console, 'connection error:'));
  db.once('open', () => {console.log.bind(console, 'connection :')});

  // the line below depends on the db
  const initRolesPolicies = require(path.resolve('./initialize/initPolicies'))();

  app.listen(port, function () {
    console.log('Autotash is running ' + process.env.NODE_ENV.toUpperCase() + ' on port ' + port + ' !');
  });

  return app;
}

module.exports = run().catch(console.err);

Steps to Reproduce

Expected behavior: All tests to run, the multiplication, the addition, and the customer creation.

Actual behavior: Only the multiplication test (the one outside the test function) run, the ones inside are completely ignored even though I execute the function at the bottom.

I don't completely like wrapping the test suites inside a function, but I have to await for the app to be returned, I am open for any other approaches to accomplish this. I just need to wait for db to be ready before exporting the app object and running the tests.

Reproduces how often: [100%]

Versions

• mocha v4.0.1
• node v8.9.3
• mongoose v5.0.14
• Windows 10
• Cmder

[ORESoftware]

First thing I notice:

const test = async () => {  // not OK =>  using async function...not kosher in this case
   // ...

  describe('math', async () => {   // this is NOT OK either
    it('adds', () => {
      let sum = 1 + 1;
      sum.should.equal(2);
    });
  });

 // ....
};

you shouldn't register any of the following asynchronously:

it/describe/before/after/afterEach/beforeEach, etc.

all hooks should be registered synchronously, otherwise you will get unknown/undefined behavior.

[AbdelrahmanHafez]

What if I need to do some async functions on before and beforeEach, like cleaning the database for example?

How should I handle that?

Edit: I misunderstood. I should write the describe(...) outside an asynchronous function, however, what I write inside the describe(...) can be async.

[AbdelrahmanHafez]

Actually, I think I just found a solution!

// test.js

const should = require('chai').should();
const request = require('supertest');
const path = require('path')
let app;

before(async () => {
  try {
    app = await require(path.resolve('./server'));
  }
  catch (err) {
    console.log(err);
  }
});

describe('math', async () => {
  it('multiplies', () => {
    let result = 2 * 2;
    result.should.equal(4);
  });
  it('adds', () => {
    let sum = 1 + 1;
    sum.should.equal(2);
  })
});

describe('users', async () => {
  it('creates a customer', async () => {
    let res = await request(app).get('/api/should-404/');
    res.status.should.equal(200);
  });
});

This did the trick after two days of trying to figure it out.

I am completely new to testing, is there a better way to do this?

[ORESoftware]

yep what you have now is good, that is a very common pattern with Mocha. Note that I made a correction to my previous statement. Let me explain better:

// this is bad
describe('foo', async _ => {
    it('bar', async done => {
    });
});

// this is good
describe('foo',  _ => {   // remove async from here
    it('bar', async done => {
    });
});

[AbdelrahmanHafez]

Thanks a lot!

[LordOfTheDings]

Thank you very much for posting your solution. I had the same problem and this provided me with the necessary information.

[AbdelrahmanHafez]

@LordOfTheDings Nothing makes me happier than coming back to things years earlier that saved someone else time. Pay it forward 👍

[RishabhAtomos]

describe('Test', () => { console.log("describe1") it('should return 200 status code', function (done) { console.log("IT") chai.request(app) .get('/v1/cis/test') .end((error, response) => { expect(response).to.have.status(200); }); done(); }); console.log("describe2") });

Why my it() is not getting executed?

[AbdelrahmanHafez]

@RishabhAtomos Your code looks right, it should run but the test doesn't really test anything because you are calling done() too quickly. Your code calls done() before the .end(...) happens

  chai.request(app)
      .get('/v1/cis/test')
      .end((error, response) => {
        expect(response).to.have.status(200);
      });
      done();

You need to move the .done() within the .end(...) callback.

  chai.request(app)
      .get('/v1/cis/test')
      .end((error, response) => {
        expect(response).to.have.status(200);
        done();
      });

That way your test exits execution only after there is a response from the chai.request().get().

Worth noting that callbacks and done() are things of the past, I highly recommend you learn more about promises and async/await, it'll make your life much easier.