SUMMARY
Mastering asynchronous behavior inside the single-threaded JavaScript runtime has long been an imposing task. With the introduction of promises in ES6 and async/await ES7, asynchronous constructs in ECMAScript have been greatly enhanced. Not only do promises and async/await enable patterns that were previously difficult or impossible to implement, but they engender an entirely new way of writing JavaScript that is cleaner, shorter, and easier to understand and debug.
Promises are built to offer a clean abstraction around asynchronous code. They can represent an asynchronously executed block of code, but they can also represent an asynchronously calculated value. They are especially useful in a situation where the need to serialize asynchronous code blocks arises. Promises are a delightfully malleable construct: They can be serialized, chained, composed, extended, and recombined.
Async functions are the result of applying the promise paradigm to JavaScript functions. They introduce...
