Mocha: Error Timeout of 2000ms exceeded

Question

I am trying to seed the database for unit test.

Below is the seed.js file:

.......
const app = require('./app')
const db = app.get('db')

const saveUsersToDB = (done) => {
    db.User.bulkCreate(users)
         .then(() => (done))
}

module.exports = {saveUsersToDB};

My app.test.js file:

.......
const expect = require('expect')
const request = require('supertest')
const {saveUsersToDB} = require('./seed/seed');

before(saveUsersToDB)

When I run the test below is the error I get:

Express listening on port 3000!
  1) "before all" hook: saveUsersToDB

  0 passing (2s)
  1 failing

  1)  "before all" hook: saveUsersToDB:
     Error: Timeout of 2000ms exceeded. For async tests and hooks, ensure "done()" is called; if returning a Promise, ensure it resolves.

npm ERR! Test failed.  See above for more details.

I thought returning .then(() => (done)) was enough? What am I doing wrong?

Answer 1

Because (done) will actually return the function instead of invoking it. In order to call done, you need to write it this way.

.then(() => done())

However, I don't recommend using done along with promises. You just simply need to return the promise then mocha will handle it automatically.

const saveUsersToDB = () => db.User.bulkCreate(users)