Node FINALLY Supports TypeScript

What is the new TypeScript support in Node.js?

Node.js has introduced a groundbreaking new feature: TypeScript support through type stripping. This enhancement enables developers to run TypeScript files directly in Node.js without needing extra transpilation steps. Traditionally, Node.js didn't natively support TypeScript, requiring tools like ts-node or various build scripts.

The new feature works by stripping types from TypeScript code during execution. This process, known as type stripping, effectively transforms TypeScript files into pure JavaScript files by removing type annotations. As a result, developers can write and execute TypeScript in Node.js without extra overhead.

The process leverages the SWC (Speedy Web Compiler). Node.js chose SWC because of its lightweight nature and efficiency in handling TypeScript-to-JavaScript compilation. Although the type stripping process does not include type checking, it streamlines the development workflow by allowing seamless execution of TypeScript files, simplifying the setup and reducing dependencies.

For more details on the broader context of TypeScript’s evolution, you can check out this article.

How does type stripping work in Node.js?

Type stripping in Node.js involves removing type annotations from TypeScript code to allow it to run as plain JavaScript. This is achieved by leveraging the SWC (Speedy Web Compiler) for transpilation. Here’s how it works:

• Type Stripping: The process extracts all TypeScript-specific syntax, leaving only valid JavaScript.
• Using SWC: Node.js employs SWC, a Rust-based transpiler, for this conversion. Its WASM (WebAssembly) support ensures compatibility across different environments by avoiding native binaries.
• No Type Checking: Unlike traditional methods, this process skips type checking, thereby speeding up the compilation and reducing overhead.

Benefits:

• Simplified Setup: Developers no longer need additional tools like ts-node for execution.
• Reduced Dependencies: By stripping types rather than checking them, the setup becomes leaner.
• Improved Workflow: Faster transpilation and execution improve the development process, making it more efficient.

This approach ensures that TypeScript files can be executed directly in Node.js with minimal fuss, enhancing developer productivity.

What is the TC39 proposal for type annotations?

The TC39 proposal aims to introduce type annotations into vanilla JavaScript. Its main goal is not to enforce type checks, but to allow developers to run TypeScript-like syntax directly in browsers.

"The goal is to enable developers to run programs that are written in TypeScript, Flow, and other static typing supersets of JS without any need for transpilation."

Copy-pasting TypeScript code into a browser currently results in syntax errors due to type annotations. This proposal seeks to change that by treating these annotations as comments rather than invalid syntax. Developers can then write TypeScript code and run it without dealing with transpilers like Babel or TypeScript's own compiler.

Key Points:

• Compatibility: Type annotations will be viewed as comments, allowing smoother execution.
• Ergonomic Syntax: The proposal aims to create a unified system that reduces developer friction.
• No Type Enforcement: Focuses solely on running the code, not checking types for errors.

Once adopted, this could unfork JavaScript, making it easier for everyone to work seamlessly with TypeScript and other superset languages.

Why is Node.js adopting SWC for TypeScript transpilation?

Node.js has adopted the SWC (Speedy Web Compiler) for TypeScript transpilation due to several key reasons:

• Efficiency: SWC is a Rust-based transpiler known for its speed and efficiency in converting TypeScript to JavaScript. It handles the transformation swiftly, minimizing delays in the development process.
• WASM Support: By leveraging WebAssembly (WASM), SWC ensures broad compatibility across different environments. This means developers can avoid the hassle of dealing with multiple native binaries, simplifying deployment.
• Lightweight Nature: Unlike other tools that may require heavy dependencies or additional installations, SWC is compact. It doesn’t add unnecessary bloat to projects, keeping them lean and fast.
• Battle-Tested: Already used by platforms like Next.js and Deno, SWC is proven in real-world scenarios. Its robustness makes it a reliable choice for large-scale applications.

Other tools such as Babel or the TypeScript compiler (TSC) could slow down projects due to their complexity and additional features. In contrast, SWC focuses solely on transpilation, offering a streamlined and faster workflow. This choice aligns well with the needs of the growing JavaScript ecosystem, ensuring that modern development practices remain efficient and effective.

For more insights into recent changes and improvements in TypeScript, you can refer to what’s new in TypeScript 5.5.

How does this change impact the JavaScript ecosystem?

The new TypeScript support in Node.js brings significant implications for the JavaScript ecosystem, transforming developer workflows, improving compatibility, and paving the way for future developments. Here are the key impacts:

1. Enhanced Developer Workflow:

   • Simplified Setup: Developers can now run TypeScript directly in Node.js without relying on additional tools like ts-node.
   • Faster Iterations: With type stripping removing the need for type checking, transpilation speed increases, leading to quicker development cycles.
   • Streamlined CI/CD: The elimination of extra dependencies and build scripts simplifies continuous integration and deployment processes.

2. Improved Compatibility:

   • Cross-Environment Execution: The use of SWC with WASM support ensures broad compatibility across different environments without the need for multiple native binaries.
   • Native ESModule Support: Both CommonJS and ESModule syntaxes are supported, allowing for greater flexibility and consistency across projects.

3. Future Developments:

   • TC39 Proposals: The integration of type annotations into vanilla JavaScript, as proposed by TC39, will enable seamless execution of TypeScript code in browsers, further aligning back-end and front-end development.
   • Ecosystem Evolution: As tools like SWC become more widely adopted, developers can expect continued improvements in performance and efficiency, fostering innovation within the ecosystem.

This move signifies a major shift, aligning with TypeScript's growing popularity and addressing developers' needs for a more efficient and compatible workflow. For more details on evolving software development practices, you can check how modern bundling with NPM works today.