Promise chaining

chain.js

// TL;DR
// return arrays

// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise/all
// http://stackoverflow.com/questions/28250680/how-do-i-access-previous-promise-results-in-a-then-chain
// http://stackoverflow.com/questions/22892681/what-patterns-are-there-for-passing-state-through-a-chain-of-promises-in-javascr
// http://bluebirdjs.com/docs/api/spread.html

// You design your api like aways, put when you want to pass a value, you pass Promise.all, and you do this in
// process of chaining it, your api, doesn't need to be awere of promises
it('Promise Chaining 1', async function() {
  Promise.all([
    Promise.resolve('hello'),
  ]).spread(value => {
    return Promise.all([Promise.resolve(value), Promise.resolve(value),])
  }).then(console.log)
    .catch(console.log)
})

it('Promise Chaining 2', async function() {
  // The thing is, you return Promise.all
  Promise.resolve('hello')
    .then(value => Promise.all([Promise.resolve(value), Promise.resolve(value)]))
    .spread((p1, p2) => {
      // spread is a then that breaks all
      // Do some function invoking, and arg passing
      return [p1, p2, Promise.resolve(p2 + "asd")]
    })
    .all()
    .then(result => {
      result.push("asdasdasd")
      return result
    })
    .then(console.log)
    .catch(console.log)
})

it('romise Chaining 3', function() {
  const endpoints = [
    'http://www.mocky.io/v2/58ebc79227000098004892fe',
    'http://mycustomdomain.lvh.me/v2/58ebc79227000098004892fe',
    'http://www.mycustomdomain.lvh.me/v2/58ebc79227000098004892fe'
  ]
  
  
    Promise.all(endpoints)
    .then(endpoints => [
      endpoints,
      Promise.all(map(pinger, endpoints))
    ])
    .all()
    .then(console.log)
    .catch(console.log)


  Promise.all(endpoints)
    .then(endpoints => [endpoints, Promise.all(map(pinger, endpoints))])
    .all()
    .then(console.log)
    .catch(console.log)

  Promise.all(endpoints)
    .then(endpoints => Promise.all([endpoints, map(pinger, endpoints)]))
    .then(console.log)
    .catch(console.log)

  Promise.all(endpoints)
    .then(endpoints => [endpoints, map(pinger, endpoints)])
    .all()
    .then(console.log)
    .catch(console.log)
})