Node.js has introduced a game-changing flag: --experimental-strip-types. This feature allows you to run TypeScript files directly without any build step! In this post, we’ll dive deep into how this works, how to use it, and its limitations. Let’s unlock the magic of running TypeScript in Node.js effortlessly!

2024-08-06, Version 22.6.0 (Current)

🌟 1. What is --experimental-strip-types?

The --experimental-strip-types flag enables Node.js to execute TypeScript files directly, bypassing the need for a separate build process. But there’s a catch—it only works with TypeScript files that don’t require transformations like enums or namespaces.

Key Points:

• TypeScript Files in Node.js: Normally, Node.js doesn't run TypeScript files natively; they need to be compiled to JavaScript.
• The --experimental-strip-types Flag: This experimental flag allows Node.js to strip away TypeScript types and run the code directly if it doesn’t include features needing compilation.

Example:

Imagine you have a simple TypeScript file:

// hello.ts
const greet: string = "Hello, Node.js!";
console.log(greet);

With the --experimental-strip-types flag, you can run this file directly in Node.js!

🛠️ 2. How to Use the --experimental-strip-types Flag

Using this flag is straightforward, but it’s important to know how to apply it correctly.

Step-by-Step Guide:

1. Create a TypeScript File: Write a basic TypeScript file (example.ts) with simple types that don’t need transformation.
2. Run with Node.js: Use the flag to execute the file.

   node --experimental-strip-types example.ts

1. Output: If your TypeScript file doesn't use features like enums or namespaces, Node.js will strip the types and execute the code as JavaScript.

Example:

// add.ts
const add = (a: number, b: number): number => a + b;
console.log(add(5, 10));

To run it:

node --experimental-strip-types add.ts

🚧 3. Limitations & Gotchas

While this feature is powerful, it has limitations. Knowing these will save you from unexpected errors.

Key Points:

• No TypeScript Transformations: The flag only works with TypeScript features that can be directly removed without needing a compilation step.
• Enums & Namespaces: If your file uses enums, namespaces, or other complex TypeScript features, Node.js will throw an error.
• Experimental Status: As the name suggests, it’s an experimental feature. It may change or be removed in future versions.

Example of a Limitation:

// enumExample.ts
enum Colors {
  Red,
  Green,
  Blue
}

console.log(Colors.Red);

Running this file with the --experimental-strip-types flag will result in an error because enums require compilation to JavaScript.

🎯 4. Why Use --experimental-strip-types?

You might wonder, why bother with this flag when you can just compile TypeScript? Here’s why:

Key Points:

• Faster Development: Avoid the compile step during development, speeding up your workflow.
• Simplified Tooling: Fewer tools required—no need for a TypeScript compiler in simple projects.
• Type Safety: Keep the benefits of TypeScript (like type checking) without the overhead of compiling.

Example Use Case:

If you’re prototyping or working on a small project with minimal TypeScript, using this flag can save time and reduce setup complexity.

📚 5. Conclusion

The --experimental-strip-types flag is a great tool for developers looking to simplify their TypeScript workflows in Node.js. While it has its limitations, it’s a powerful option for those working with simple TypeScript files. Give it a try in your next project and experience the magic of running TypeScript without a build step!