yio

Yield IO.

Yield makes it easy to write async code in a nice testable way. Yield takes two functions: io and control. io is responsible for performing io. It takes a single value and returns a promise. control is responsible for control flow. All values yielded by control are passed to io and the resolved promise is yielded. A great way to use yio is for control to yield action creators (ala redux) and for io to proces the action creators.

yio is similar to co, except that it promots pushing io to the edges. The advantage of this is that all the complex logic can be done in control and control can be easily tested without performing io. No need for mocks or DI.

Installation

$ npm install yio

Example

Basic

import yio from 'yio'

function log (val) {
  console.log('val', val)
}

//output:
//1
//2
//3
yio(log, function * () {
  yield 1
  yield 2
  yield 3
})

Async

import yio from 'yio'
import fetch from 'whatwg-fetch'

function dispatchFetch (options) {
  return fetch(options).then((res) => res.json())
}

//output:
//josh
//tio
//elliot
yio(dispatchFetch, function * () {
  let userIds = yield {url: '/users', method: 'GET'}
  for (let userId in userIds) {
    let user = yield {url: '/user/' + userId, method: 'GET'}
    console.log(user.name)
  }
})

Yields

Use yio with yields.

import yio from 'yio'
import yields from 'yields'

function log (val) {
  console.log('val', val)
}

//output:
//1
//2
//3
yio(
  log,
  yields(function () {
    return 1
  })
  .yields(function () {
    return 2
  })
  .yields(function () {
    return 3
  })
)

Parallel Async

import yio from 'yio'
import fetch from 'whatwg-fetch'

function dispatchFetch (options) {
  return fetch(options).then(function(res) {
    return res.json()
  })
}

//output:
//josh
//tio
//elliot
yio(dispatchFetch, function * () {
  let userIds = yield {url: '/users', method: 'GET'}
  let users = yield userIds.map(userId => ({url: '/user/' + userId, method: 'GET'}))
  users.forEach(() => {
    console.log(user.name)
  })
})

License

The MIT License

Copyright © 2015, Weo.io <info@weo.io>

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.