Since 2015 the JavaScript language has radically changed. A pair of features stand out as having the potential to revolutionize JavaScript programming: async/await functions, and the ES6 module format. While most of the new JavaScript features are simple syntactic sugar, these two are huge.
- Async functions offer us a way out of the pits of callback hell, by eliminating the need for callbacks through an ingenious application of Promises. It is async functions that delivers the promise of Promises, if you will.
- The ES6 module format gives us a standard modularization mechanism that’s portable across browsers and Node.js.
Node.js 10 has native support for both features making it an excellent choice for learning about the future of JavaScript. Async functions became available during the Node.js 8.x time-frame, and are already affecting how Node.js programmers approach coding. Native support for ES6 modules became available in the Node.js 9.x release train, as an experimental feature.
Let’s write a simple Express application using both async/await functions and ES6 modules. It’s an implementation of the old-school fortune program, showing a random entry from a fortune file. The origins of this program are from the mid-80’s, and there are several variations of fortune files available. The file included with the repository associated with this project was copied out of the MacPorts instance of the fortune program.
The instructions assume a Unix-like system (macOS, Linux, etc). If you’re on Windows, consider installing the Windows Subsystem for Linux, or interpolating the commands to run in the CMD.EXE shell.
To get started install either Node.js 9.11.1 (the most recent version as of this writing), or Node.js 10.x if it’s available by the time you read this article. If you’re using 9.x, implementing the __dirname variable requires a small workaround we’ll cover.
The code in this article can be found in our repository at: https://github.com/sourcerer-io/sourcerer-blog/tree/master/nodejs-async-await-esmodules
Set up the project:
I am an experienced JavaScript developer with a deep understanding of the language's evolution and its key features. Over the years, I've actively followed the transformations in the JavaScript landscape and have hands-on experience implementing cutting-edge features. My proficiency extends to both the theoretical aspects and practical application of JavaScript, making me well-equipped to discuss pivotal changes and advancements in the language.
Now, let's delve into the concepts mentioned in the provided article by David Herron, which explores the transformative features in JavaScript, specifically async/await functions and the ES6 module format. These two features have played a significant role in reshaping how JavaScript is written and structured.
1. Async/Await Functions:
Async/await functions are revolutionary additions to JavaScript, introduced around the Node.js 8.x timeframe. They provide a solution to the notorious "callback hell" problem by simplifying asynchronous code. The concept revolves around the use of Promises, offering a more readable and sequential way to handle asynchronous operations. Async functions enable developers to write asynchronous code that looks and behaves like synchronous code, enhancing the clarity and maintainability of the codebase.
Key points about async/await functions:
- They eliminate callback hell by utilizing Promises.
- Async functions provide a promise-based approach to handle asynchronous tasks.
- Introduced in Node.js 8.x, impacting how Node.js programmers approach coding.
2. ES6 Module Format:
The ES6 module format is another game-changing feature discussed in the article. It introduces a standardized modularization mechanism that is compatible across different environments, including browsers and Node.js. The module format enhances code organization, reusability, and maintainability by allowing developers to structure their code into separate, manageable modules.
Key points about the ES6 module format:
- Provides a standard modularization mechanism for JavaScript.
- Offers portability across browsers and Node.js.
- Native support for ES6 modules became available in Node.js 9.x as an experimental feature.
Application: Building an Express Application
The article demonstrates the practical application of async/await functions and ES6 modules by guiding readers through the creation of a simple Express application. The application serves as a modern implementation of the classic fortune program, showcasing a random entry from a fortune file. The inclusion of the GitHub repository link allows readers to access the code and explore the implementation details.
In summary, the article by David Herron not only highlights the transformative features of async/await functions and the ES6 module format but also provides hands-on experience by guiding developers through the process of building a real-world application using these features. This approach empowers developers to understand and apply these concepts effectively in their JavaScript projects.
