Awesome Promises

A curated list of useful resources for JavaScript Promises

Inspired by the 304043⭐  26877🍴 awesome) list thing. Not to be confused with other awesome promises like "I promise you a million dollars" or "I promise you'll stay fit and never have to go to the gym again".

Table of Contents

• Resources, Blogs, and Books
• Promises/A+ Implementations (ES6/ES2015 compatible)
  • Strict Implementations
  • Implementations with extras
  • Fallbacks
• Convenience Utilities

Resources, Blogs, and Books

For beginners

•   1610⭐    197🍴 Promise Cookbook) - The why, what, and how. "A brief introduction [...] primarily aimed at frontend developers".
• Promises for Asynchronous Programming - Chapter from Exploring ES6
• 176958⭐  33299🍴 You Don't Know JS: Promises) - Chapter from 176958⭐  33299🍴 You Don't Know JS: Async & Performance)
• 🌎 JavaScript Promises: an Introduction - Basics of JavaScript's native promise implementation.
• JavaScript with Promises - from O'Reilly. Short and to-the-point. Uses native and bluebird.
•    733⭐    219🍴 Promise it won't hurt) - An interactive 🌎 nodeschool workshop
• ES6 Kata Promises - Promises Katas : Basics
• 🌎 ES6 Promises in Depth
• An Incremental Tutorial on Promises - An FAQ styled tutorial for beginners.

Deep Dive

•   4609⭐    126🍴 Promise Fun) - @sindresorhus's notes, patterns, and solutions to common Promise problems
• 🌎 You're Missing the Point of Promises - Promises are much more than callback aggregation, and that jQuery's implementation (prior to 3.0) isn't enough.
• 🌎 We have a problem with promises - "Many of us are using promises without really understanding them."
•      ?⭐      ?🍴 Promise anti-patterns) - Common misuses and how to avoid them.
• Promise anti-patterns (2) - Another set of promises anti-patterns
• 🌎 Promise Ponderings, (Anti-)Patterns, and Apologies - Promise behaviour demonstrated and explained by common questions and their answers.
• Javascript Promises...In Wicked Detail - Recreate the promise implementation
• 🌎 Writing Promise-Using Specifications - "This document gives guidance on how to write specifications that create, accept, or manipulate promises"
• 🌎 Async functions - making promises friendly

References

• 🌎 Promises/A+ specification
• caniuse promises
•   1222⭐     93🍴 Fates and States) - Quick definitions of possible states.
• 🌎 Promisees - Promise visualization playground for the adventurous.

Promises/A+ Implementations (ES6/ES2015 compatible)

Strict Implementations

These implement no more or less than the es6 spec. They make great polyfills and are exceptionally compatible with native promises.

•    137⭐     19🍴 pinkie) - Ponyfill. Node-oriented, but  14539⭐   1187🍴 browserifyable). Extremely small implementation.
•    725⭐     78🍴 native-promise-only) - Polyfill. Browser and node-compatible.
•   7298⭐    593🍴 es6-promise) - Opt-in polyfill. A strict-spec subset of rsvp.js.
•    746⭐     67🍴 lie) - Small, browserifyable with an opt-in polyfill.

Implementations with extras

All of these provide more features than the language yet remain compatible. Node + Browsers for all.

•  20430⭐   2334🍴 bluebird) - Fully featured, extremely performant. Long stack traces & generator/coroutine support.
•    273⭐     20🍴 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!
•  14952⭐   1202🍴 Q) - One of the original implementations. Long stack traces and other goodies.
•   2561⭐    309🍴 then/promise) - Small with nodeify, denodify and done() additions.
•   3436⭐    395🍴 when.js) - Packed with control flow, functional, and utility methods.

Fallbacks

• 🌎 native-or-bluebird - Helps transition to completely native.
•    119⭐     17🍴 pinkie-promise) - Use native, or fall back to pinkie. Great for node library authors.
•    179⭐     18🍴 any-promise) - Loads the first available implementation. Safe for browserify.

Convenience Utilities

Native and strictly spec-compliant promises are awesome for compatibility, future-proofness, library authors, and browsers. However, libraries like bluebird patch goodies onto the Promise constructor and prototype. Solution? tiny modules of course!

sindresorhus's many Promise utilities (  4609⭐    126🍴 see notes))

•    605⭐     43🍴 delay) - Delay a promise a specified amount of time.
•   1503⭐     67🍴 pify) - Promisify ("denodify") a callback-style function.
•    281⭐     24🍴 loud-rejection) - Make unhandled promise rejections fail loudly instead of the default silent fail.
•    106⭐      8🍴 hard-rejection) - Make unhandled promise rejections fail hard right away instead of the default silent fail
•   3281⭐    175🍴 p-queue) - Promise queue with concurrency control
•     21⭐      5🍴 p-break) - Break out of a promise chain
•    263⭐     10🍴 p-lazy) - Create a lazy promise that defers execution until .then() or .catch() is called
•     66⭐      8🍴 p-defer) - Create a deferred promise
•     58⭐      6🍴 p-if) - Conditional promise chains
•    131⭐      9🍴 p-tap) - Tap into a promise chain without affecting its value or state
•   1232⭐     56🍴 p-map) - Map over promises concurrently
•    301⭐     13🍴 p-all) - Run promise-returning & async functions concurrently with optional limited concurrency
•   1734⭐     95🍴 p-limit) - Run multiple promise-returning & async functions with limited concurrency
•     36⭐      5🍴 p-times) - Run promise-returning & async functions a specific number of times concurrently
•     37⭐      5🍴 p-catch-if) - Conditional promise catch handler
•     68⭐      5🍴 p-time) - Measure the time a promise takes to resolve
•     24⭐      4🍴 p-log) - Log the value/error of a promise
•     70⭐      8🍴 p-filter) - Filter promises concurrently
•     89⭐     11🍴 p-settle) - Settle promises concurrently and get their fulfillment value or rejection reason
•    373⭐     32🍴 p-memoize) - Memoize promise-returning & async functions
•     51⭐      8🍴 p-whilst) - Calls a function repeatedly while a condition returns true and then resolves the promise
•    394⭐     28🍴 p-throttle) - Throttle promise-returning & async functions
•    197⭐     23🍴 p-debounce) - Debounce promise-returning & async functions
•    757⭐     58🍴 p-retry) - Retry a promise-returning or async function
•    150⭐     19🍴 p-wait-for) - Wait for a condition to be true
•    262⭐     29🍴 p-timeout) - Timeout a promise after a specified amount of time
•     45⭐      5🍴 p-race) - A better Promise.race()
•     52⭐     12🍴 p-try) - Promise#try() ponyfill - Starts a promise chain
•     45⭐      8🍴 p-finally) - Promise#finally() ponyfill - Invoked when the promise is settled regardless of outcome
•     54⭐      7🍴 p-any) - Wait for any promise to be fulfilled
•     34⭐      8🍴 p-some) - Wait for a specified number of promises to be fulfilled
•    118⭐     16🍴 p-pipe) - Compose promise-returning & async functions into a reusable pipeline
•     48⭐      7🍴 p-each-series) - Iterate over promises serially
•     46⭐      4🍴 p-map-series) - Map over promises serially
•     66⭐      7🍴 p-reduce) - Reduce a list of values using promises into a promise for a value
•    188⭐     25🍴 p-props) - Like Promise.all() but for Map and Object

Others

•      2⭐      0🍴 promise-method) - Standalone bluebird.method. Turn a synchronously-returning method into a promise-returning one.
•    281⭐     32🍴 is-promise) - Determine if something looks like a Promise.
•     14⭐      0🍴 sprom) - Resolve when a stream ends. Optional buffering (be careful with this!)
•   1631⭐     72🍴 task.js) - Write async functions in a blocking style using promises and generators. Like bluebird.coroutine.
•  11873⭐    794🍴 co) - Like task.js and bluebird.coroutine, but supports thunks too.
• 🌎 lie-fs - Promise wrappers for Node's FS API.
•      1⭐      0🍴 promise-do-until) - Calls a function repeatedly until a condition returns true and then resolves the promise.
•      3⭐      1🍴 promise-do-whilst) - Calls a function repeatedly while a condition returns true and then resolves the promise.
•     29⭐     10🍴 promise-semaphore) - Push a set of work to be done in a configurable serial fashion
•      2⭐      0🍴 promise-nodeify) - Standalone nodeify method which calls a Node-style callback on resolution or rejection.

License

Licensed under the 🌎 Creative Commons CC0 License.

Source

  1596⭐    132🍴 wbinnssmith/awesome-promises)