promises-pipes v0.0.4

promises-pipes

promises-pipes package includes a set of useful functions that simplify dealing with iterative promises.

Getting Started

Installation

npm i promises-pipes

Usage

const {series} = require('promises-pipes')

function promiseFunction(...args) {
	return new Promise((resolve, reject) => {
        setTimeout(function () {
            resolve(args)
        }, 100);
    })
}

let promises = [
	[promiseFunction, 'Hello','World'],
	[promiseFunction, 1, 2, 3],
    [promiseFunction]
]

series(promises)
	.then(results => {
    	// results array
        // [ [ 'Hello', 'World' ], [ 1, 2, 3 ], [] ]
    })
    .catch(err => {
    	throw err
    })

Methods

Each method execute tasks in a different behavior, eather sequencial or parallel.

Task A task is an array [promiseFunction, ...args], The first item of the array should be a function that returns a promise, and the rest of the items are the arguments that the function expects.

series

Excute tasks sequentially

series([tasks])

seriesTimes

Excute task multiple times sequentially

seriesTimes(task, number)

parallel

Excute parallel tasks, does not guarantee the sequence of execution.

parallel([tasks])

limitedParallel

Excute parallel tasks but limit the number of running tasks.

limitedParallel([tasks], limit, stopFunction)

stopFunction

Can be added to limitedParallel function, makes limitedParallel reject with error that is instance of StopPipe class and has the stopResponse which is the first result that met the stopFunction condition.

const {limitedParallel, StopPipe} = require('promises-pipes')

function stopFunction(result) {
	return (condition)
}

limitedParallel([tasks], limit, stopFunction)
	.then(result)
	.catch(StopPipe => {
		// StopPipe instance
	})