a.js

const genericPool = require('generic-pool');
const factory = {
    create: function(){  return Promise.reject(new Error('cannot create resource'))}
    ,destroy:  function () { return Promise.resolve() }
}

const opts = {
  acquireTimeoutMillis: 1000
}

const myPool = genericPool.createPool(factory, opts)

myPool.acquire().then(function() {console.log('ok')}).catch((err)=>{console.log(err)})