Breeze

Functional async flow control library built on promises. Managing promises and async code has never been easier.

Features

• Small footprint
• Native promise support
• No chaining required
• Benchmarking (yes, even Promises)
• Logging (Chain logs, argument logs, and more...)

Install

• Download the latest package
• NPM: npm install breeze

Usage

Node.js / Browserify / Webpack

const Breeze = require('breeze')

Documentation

Breeze Flow

import Breeze from 'breeze'

let flow = new Breeze()

Breeze Flow Instance Methods

then(method: Function|Promise)

Add step to flow chain.

flow
  .then(value => 'function with return value')
  .then(value => console.log('function says:', value))
  .then(new Promise((resolve, reject) => {
    return resolve('Promise resolution')
  }))
  .then(value => console.log('promise says:', value))

Note: You are not required to chain instance methods.

flow.then(value => 'function with return value')
flow.then(value => console.log('function says:', value))

catch(type?: ErrorType, handler: Function)

Handle chain rejections. Accepts an optional custom error type to capture specific rejections in the flow chain.

flow.then(() => throw new Error('Spoiler Alert'))

flow.catch(CustomError, err => console.log('Specialized Catch:', err))

flow.catch(err => console.log('Generic Catch:', err))

id(name: String)

Identify a step. Useful for benchmarking and logs.

// Create a flow step
flow.then(results => client.get('/users'))

// Identify step for benchmarking and logs
flow.id('fetch-users')

each(promises: Array, method: Function)

Invoke method on results of each Promise in the given Array.

Todo: Support previous chain Array<Promise> value.

all(promises: Array)

Map promise results to an array in order resolved.

map(promises: Array)

Map promise results to an array in given order.

skip(steps: Number)

Skip n steps after this point.

get(index: Number)

Obtain entry in array at given index in next step.

flow
  .then(() => [1,2,3])
  .get(0)
  .then(item => console.log(item)) // Outputs: 1

when(conditional: Function|Truthy, method: Function)

Invokes method when the conditional argument is truthy, otherwise skips to the next step.

flow
  .then(() => [1, 2, 3])
  .when(result => result[0] === 1, result => console.log(result[0], '=', 1))

This is a basic example to illustrate the small power of how you can make if statements asynchronous.

spread(method: Function)

Spreads each argument from a successful step as individual arguments on the passed method

flow
  .then(() => ['username', 'Steven Seagal'])
  .spread((field, value) => console.log(field, '=', value)) // username = Steven Seagal

tap(method: Function)

Invoke method without modifying the return result of the step, useful for inspection.

flow
  .then(() => [1, 2, 3])
  .tap(result => console.log(result))
  .then(result => console.log(result)) // [1,2,3]

return(value: any)

Convenience method for:

.then(() => value)

throw(reason: any)

Convenience method for:

.then(() => throw error)

License

Licensed under The MIT License.