Top Level Await Configuration

Let’s dive into the intriguing world of JavaScript, particularly focusing on a feature that’s been catching the eyes of developers: Top Level Await. This feature is a significant evolution in how we write asynchronous code, making it simpler and more intuitive. But before you can start refactoring your code to use Top Level Await, there are a few setup steps you need to take to ensure your environment is ready.

First and foremost, Top Level Await is designed to work with ECMAScript Modules (ESM). This means you have two primary ways to ensure your project is set up correctly to take advantage of this feature:

1. Using package.json Configuration: The most straightforward method is to declare your project as a module explicitly. You can do this by adding "type": "module" to your package.json file. This simple addition signals to Node.js that you’re working with ECMAScript Modules, paving the way for Top Level Await and other ESM features.

2. File Extension Approach: If modifying package.json doesn’t suit your project structure or you’re looking for a more granular approach, you can opt to use the .mjs extension for your JavaScript files. Files with this extension are automatically treated as ECMAScript Modules by Node.js, making them eligible for Top Level Await.

For those working in a TypeScript environment, an additional step is required. TypeScript needs to be informed that you’re using ECMAScript Modules and that you’re targeting a JavaScript environment that supports Top Level Await. This is done by adjusting your tsconfig.json:

• Set "module" to ES2022 or newer. This tells TypeScript to generate code that’s compatible with ECMAScript Modules.
• Ensure "target" is also set to ES2022 or above to leverage the latest JavaScript features, including Top Level Await.

By following these steps, you’re not just unlocking the power of Top Level Await; you’re also embracing the modern JavaScript ecosystem’s best practices. This setup ensures your project is future-proofed, taking full advantage of the latest language features and making your asynchronous code cleaner and more maintainable.

Whether you’re starting a new project or updating an existing one, integrating Top Level Await can significantly impact how you handle asynchronous operations. With your environment correctly configured, you’re now ready to simplify your async code, making it more readable and expressive.