awesome-promises

Promise Cookbook

The why, what, and how. "A brief introduction [...] primarily aimed at frontend developers"

Chapter from

You Don't Know JS: Promises

Chapter from

Basics of JavaScript's native promise implementation

from O'Reilly. Short and to-the-point. Uses native and bluebird

Promise it won't hurt

An interactive workshop

Promises Katas :

An FAQ styled tutorial for beginners

Promise Fun

@sindresorhus's notes, patterns, and solutions to common Promise problems

Promises are much more than callback aggregation, and that jQuery's implementation (prior to 3.0) isn't enough

"Many of us are using promises without really understanding them."

Promise anti-patterns

Common misuses and how to avoid them

Another set of promises anti-patterns

Promise behaviour demonstrated and explained by common questions and their answers

Recreate the promise implementation

"This document gives guidance on how to write specifications that create, accept, or manipulate promises"

Fates and States

Quick definitions of possible states

Promise visualization playground for the adventurous

pinkie

Ponyfill. Node-oriented, but . small implementation

native-promise-only

Polyfill. Browser and node-compatible

es6-promise

Opt-in polyfill. A strict-spec subset of rsvp.js

lie

Small, browserifyable with an opt-in polyfill

bluebird

Fully featured, extremely performant. Long stack traces & generator/coroutine support

creed

Hyper performant & full featured like Bluebird, but FP-oriented. Coroutines, generators, promises, ES2015 iterables, & fantasy-land spec

rsvp.js

Lightweight with a few extras. Compatible down to IE6!

Q

One of the original implementations. Long stack traces and other goodies

then/promise

Small with , and additions

when.js

Packed with control flow, functional, and utility methods

Helps transition to completely native

pinkie-promise

Use native, or fall back to . Great for node library authors

any-promise

Loads the first available implementation. Safe for browserify

delay

Delay a promise a specified amount of time

pify

Promisify ("denodify") a callback-style function

loud-rejection

Make unhandled promise rejections fail loudly instead of the default silent fail

hard-rejection

Make unhandled promise rejections fail hard right away instead of the default silent fail

p-queue

Promise queue with concurrency control

p-break

Break out of a promise chain

p-lazy

Create a lazy promise that defers execution until or is called

p-defer

Create a deferred promise

p-if

Conditional promise chains

p-tap

Tap into a promise chain without affecting its value or state

p-map

Map over promises concurrently

p-all

Run promise-returning & async functions concurrently with optional limited concurrency

p-limit

Run multiple promise-returning & async functions with limited concurrency

p-times

Run promise-returning & async functions a specific number of times concurrently

p-catch-if

Conditional promise catch handler

p-time

Measure the time a promise takes to resolve

p-log

Log the value/error of a promise

p-filter

Filter promises concurrently

p-settle

Settle promises concurrently and get their fulfillment value or rejection reason

p-memoize

Memoize promise-returning & async functions

p-whilst

Calls a function repeatedly while a condition returns true and then resolves the promise

p-throttle

Throttle promise-returning & async functions

p-debounce

Debounce promise-returning & async functions

p-retry

Retry a promise-returning or async function

p-wait-for

Wait for a condition to be true

p-timeout

Timeout a promise after a specified amount of time

p-race

A better

p-try

ponyfill - Starts a promise chain

p-finally

ponyfill - Invoked when the promise is settled regardless of outcome

p-any

Wait for any promise to be fulfilled

p-some

Wait for a specified number of promises to be fulfilled

p-pipe

Compose promise-returning & async functions into a reusable pipeline

p-each-series

Iterate over promises serially

p-map-series

Map over promises serially

p-reduce

Reduce a list of values using promises into a promise for a value

p-props

Like but for and

promise-method

Standalone . Turn a synchronously-returning method into a promise-returning one

is-promise

Determine if something looks like a Promise

sprom

Resolve when a stream ends. Optional buffering (be careful with this!)

task.js

Write async functions in a blocking style using promises and generators. Like

co

Like and , but supports thunks too

Promise wrappers for Node's FS API

promise-do-until

Calls a function repeatedly until a condition returns true and then resolves the promise

promise-do-whilst

Calls a function repeatedly while a condition returns true and then resolves the promise

promise-semaphore

Push a set of work to be done in a configurable serial fashion

promise-nodeify

Standalone method which calls a Node-style callback on resolution or rejection