Colorkrew Blog

If you became a frontend engineer after 2015, chances are that you have used or at least heard about Promise. As I have covered in my previous blog, Promise can help us specify sequential relations between operations in asynchronous programming in a readable and maintainable manner. Promise object in JavaScript has methods, such as then and catch, that can help us organize the sequential execution of operations in a pattern called Promise Chaining. Clean and organized as Promise Chaining is, some people—especially those more accustomed to synchronous programming—find it unintuitive and confusing. Lucky for them, ECMAScript 2017 introduced a new feature that allows us to write asynchronous code as if it were synchronous. This new feature consists of two keywords: async and await. In this article, I will cover the fundamentals of async/await and how to transition from Promise Chaining to using async/await.

If you have done any web development after 2015, chances are that you have heard of the concept of Promise. It wouldn’t be an overstatement to claim that Promise is ubiquitous in modern-day front-end codebases. However, many web developers—especially those who do not have much experience in front-end development—have been using Promise without thoroughly understanding its inner working. This has led to countless misuses of Promise and consequent bugs. In this article, I will walk you through what motivated the creation of Promise, how Promise works, and how we should use it in our code, under the assumption that you don’t have much experience in front-end development.