setup.js

const CurlRequest = require('curl-request')
const knex = require('knex')

const wait = ms => new Promise(resolve => setTimeout(resolve, ms))
const WAIT_TIME = 5000
const MAX_RETRIES = 10

const curl = new CurlRequest()

const waitForDb = async ({url, fn, retries=0}) => {
  if(retries ++ >= MAX_RETRIES) {
    console.log(`****** ERROR: Unable to connect: ${url}`)
    process.exit(1)
  }
  if(!await fn()) {
    console.log(`====> Waiting on ${url} to become available.`)
    await wait(WAIT_TIME)
    await waitForDb({url: url, fn: fn, retries: retries})
  }
}

const waitForCouch = async (url) => {
  await waitForDb({url: url, fn: async () => {
    try {
      const {statusCode} = await curl.get(url)
      if(statusCode === 200) {
        console.log(`- Couch [${url}] is now avaliable.`)
        return true
      }
    } catch(err) {}
  }})
}

const waitForPg = async (url) => {
  const conn = knex({client: 'pg', connection: url})
  await waitForDb({url: url, fn: async () => {
    try {
      await conn.raw('SELECT * FROM pg_catalog.pg_tables')
      console.log(`- Postgres [${url}] is now avaliable.`)
      await conn.destroy()
      return true
    } catch(err) {
      if(err.code !== 'ECONNREFUSED') {
        process.exit(1)
      }
    }
  }})
}

module.exports = async () => {
  await waitForCouch(process.env.TEST_COUCH_URL)
  await waitForPg(process.env.TEST_PG_URL)
}