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The jump to lightspeed

· 3 min read
Mikael Pettersson
Mikael Pettersson
NexusDI Author

NexusDI just made the jump to lightspeed! With our latest release, you can say goodbye to reflect-metadata, enjoy a cleaner module API, and rest easy knowing your DI setup is ready for the next era of TypeScript and JavaScript. Let's take a tour of what's new, why it matters, and how to upgrade.

⚡ Native Decorator Metadata (No More reflect-metadata!)​

NexusDI now uses the new ECMAScript decorator metadata standard via Symbol.metadata, as supported in TypeScript 5.2+ and the upcoming JavaScript standard.

  • No more reflect-metadata: You don't need to install or import it—ever (unless your other dependencies require it).
  • Cleaner tsconfig: No more emitDecoratorMetadata. Just enable experimentalDecorators and (optionally) useDefineForClassFields (the default in TS 5.2+).
  • Automatic polyfill: NexusDI includes a tiny, built-in polyfill for Symbol.metadata if your runtime doesn't support it yet. No extra setup required.
  • Future-proof: Your code is ready for the next generation of TypeScript and JavaScript.

"It's like switching from a hyperdrive that needs constant repairs to one that just works."

Example​

import { Service, Inject, Nexus, Token } from '@nexusdi/core';

const USER_SERVICE = new Token('UserService');

@Service()
class UserService {
  getUsers() {
    return ['Alice', 'Bob', 'Charlie'];
  }
}

const container = new Nexus();
container.set(USER_SERVICE, UserService);

const userService = container.get(USER_SERVICE);
console.log(userService.getUsers()); // ['Alice', 'Bob', 'Charlie']

Note: NexusDI v0.3+ uses native decorator metadata (TypeScript 5.2+). You do not need to install or import reflect-metadata, and you do not need emitDecoratorMetadata in your tsconfig. Only experimentalDecorators and useDefineForClassFields (default in TypeScript 5.2+) are required.

📦 Unified Module API: services and providers Merged​

Modules are now simpler and less confusing! Instead of juggling both services and providers arrays, you now use a single providers array for everything:

Before:

@Module({
  services: [UserService],
  providers: [{ token: USER_REPO, useClass: UserRepo }],
})
export class UserModule {}

Now:

@Module({
  providers: [UserService, { token: USER_REPO, useClass: UserRepo }],
})
export class UserModule {}
  • Less boilerplate: One array, all your dependencies.
  • Clearer intent: No more guessing where things go.

🎯 Why This Matters​

  • Smaller bundles: No more reflect-metadata means less code in your app.
  • Faster startup: Native metadata is faster and more reliable.
  • Modern and future-proof: Aligns with the latest TypeScript and ECMAScript standards.
  • Easier migration: The new module API is simpler and more intuitive.

🔧 How to Upgrade​

  1. Update TypeScript: Make sure you're on TypeScript 5.2 or later.
  2. Update your tsconfig:
    • Cleanup emitDecoratorMetadata, if you don't need it for anything else
    • Ensure experimentalDecorators is enabled
    • (Optional) useDefineForClassFields should be enabled (default in TS 5.2+)
  3. Remove all imports of reflect-metadata.
  4. Update your modules: Merge services and providers into a single providers array.
  5. Enjoy a cleaner, faster, and more modern DI experience!

🧑‍💻 Other Notable Improvements​

  • Dynamic Modules: More flexible module registration and configuration. (was ghost launched in 0.2)
  • Better Type Safety: Improved generics and overloads for decorators and containers.
  • Performance: Optimized for tree-shaking and minimal runtime overhead.
  • Polyfill Included: No manual setup for Symbol.metadata—it just works.

🛣️ Next Steps​

✨ Lets boldly go where few have gone before!​

This release is a big step toward a simpler, more powerful, and future-ready dependency injection experience for TypeScript and JavaScript developers. We can't wait to see what you build with NexusDI!

Have questions, feedback, or want to contribute? Check out our docs, join the discussion, or open an issue.

Want to help improve NexusDI?
Read our contribution guidelines and join the journey! 🚀