Notes for a quick presentation to introduce other developers to Promises

intro_to_promises.md

Promises

Why?

• reclaim simple synchronous control flow like return & throw
• easier to write and maintain
• banish callback hell

How?

• gives each async call state: pending, fulfilled, rejected
• lets you break up asynchronous nested callbacks into chained synchronous logic
• use bluebird

Working with promises:

• .then()
• .catch() / .finally()
• .props()
• .map() / .reduce() / .filter()
• .tap()
• More convenience methods: .get(), .return(), .delay()

Turning into promises?

• Promise.promisifyAll()
• promisify()
• resolve()
• new Promise(function (resolve, reject) {})