p-pipe

What is p-pipe?

The p-pipe npm package allows you to compose promise-returning & async functions into a pipeline. It is useful for creating a sequence of asynchronous operations where the output of one function is passed as the input to the next.

What are p-pipe's main functionalities?

Basic Pipeline

This feature allows you to create a basic pipeline of asynchronous functions. In this example, the `add` function increments the input by 1, and the `multiply` function doubles the result. The pipeline processes the input `5` to produce the output `12`.

const pPipe = require('p-pipe');

const add = async x => x + 1;
const multiply = async x => x * 2;

const pipeline = pPipe(add, multiply);

pipeline(5).then(result => console.log(result)); // 12

Error Handling

This feature demonstrates how p-pipe handles errors in the pipeline. If any function in the pipeline throws an error, the pipeline will stop executing and return the error. In this example, the `throwError` function throws an error, which is caught and logged.

const pPipe = require('p-pipe');

const add = async x => x + 1;
const throwError = async x => { throw new Error('Something went wrong'); };
const multiply = async x => x * 2;

const pipeline = pPipe(add, throwError, multiply);

pipeline(5).catch(error => console.error(error.message)); // 'Something went wrong'

Synchronous Functions

This feature shows that p-pipe can also handle synchronous functions. The pipeline processes the input `5` to produce the output `12`, similar to the asynchronous example.

const pPipe = require('p-pipe');

const add = x => x + 1;
const multiply = x => x * 2;

const pipeline = pPipe(add, multiply);

pipeline(5).then(result => console.log(result)); // 12

Other packages similar to p-pipe

p-waterfall

p-waterfall is another package for composing promise-returning & async functions. It executes functions in series, passing the result of each function to the next. Unlike p-pipe, p-waterfall is more focused on a waterfall model where each function depends on the result of the previous one.

async

The async package provides a wide range of utilities for working with asynchronous JavaScript. It includes methods for creating series, parallel, and waterfall workflows. While it is more feature-rich compared to p-pipe, it can be more complex to use for simple pipelines.

promise-pipeline

promise-pipeline is a package for creating pipelines of promise-returning functions. It is similar to p-pipe but offers additional features like conditional execution and branching. It provides more flexibility at the cost of added complexity.

README

p-pipe

Compose promise-returning & async functions into a reusable pipeline

Install

$ npm install --save p-pipe

Usage

const pPipe = require('p-pipe');

const addUnicorn = str => Promise.resolve(`${str} Unicorn`);
const addRainbow = str => Promise.resolve(`${str} Rainbow`);

const pipeline = pPipe(addUnicorn, addRainbow);

pipeline('❤️').then(console.log);
//=> '❤️ Unicorn Rainbow'

API

pPipe(input, …)

The input functions are applied from left to right.

You can also specify an array as the first argument instead of multiple function arguments. Mostly only useful if you have to support Node.js 4. With Node.js 6 and above you can just use spread syntax.

input

Type: Function

Expected to return a Promise or any value.

Related

• p-each-series - Iterate over promises serially
• p-series - Run promise-returning & async functions in series
• p-waterfall - Run promise-returning & async functions in series, each passing its result to the next
• More…

License

MIT © Sindre Sorhus