utils.test.js

const mongoose = require('mongoose')
const pkg = require('./package')

const getMongo = ({
  mongoUrl,
  dropDatabase = true,
  connectionWhitelist
}) => {
  if (mongoose.connection.host) {
    throw new Error(`There was already a mongoose connection, this is dangerous. Was connected to: ${mongoose.connection.host}`)
  }

  let hasConnected = false

  const connect = async () => {
    await mongoose.connect(mongoUrl, {
      useNewUrlParser: true,
      promiseLibrary: global.Promise
    })

    hasConnected = true

    // eslint-disable-next-line no-console
    console.log(`Connected to test database at ${mongoUrl}`)
  }

  const drop = async () => {
    if (!hasConnected) {
      throw new Error('Was trying to drop the database, but was not connected to the test database.')
    }

    if (!connectionWhitelist.includes(mongoose.connection.client.s.url)) {
      throw new Error('Was trying to a non-whitelisted database, cancelled.')
    }

    await mongoose.connection.db.dropDatabase()

    // eslint-disable-next-line no-console
    console.log(`Dropped the test database`)
  }

  const close = async () => {
    // eslint-disable-next-line no-console
    console.log(`Closing mongoose connection`)

    if (!mongoose.connection) {
      throw new Error('Could not close the connection, there was none.')
    }

    if (!hasConnected) {
      throw new Error(`Wanted to close connection to: ${mongoose.connection.host}, but was not connected to url: ${mongoUrl}`)
    }

    await Promise.all(mongoose.modelNames().map(model => {
      return mongoose.model(model).ensureIndexes()
    }))

    await mongoose.disconnect()

    hasConnected = false

    // eslint-disable-next-line no-console
    console.log(`Connection to mongoose closed`)
  }

  return {
    connect,
    drop,
    close
  }
}

const mongo = getMongo({
  mongoUrl: `mongodb://127.0.0.1:27017/${pkg.name}-test`,
  connectionWhitelist: [
    `mongodb://127.0.0.1:27017/${pkg.name}-test`
  ]
})

global.before(async () => {
  if (process.env.NODE_ENV !== 'mocha') {
    throw new Error(`NODE_ENV should be set to "mocha".`)
  }

  await mongo.connect()
  await mongo.drop()
})

global.after(async () => {
  await mongo.close()
})