tRPC Decorator

A library to simplify building tRPC routes using decorator syntax, enhancing ease of use and compatibility with Dependency Injection paradigms like TSyringe.

Benefits

• Class-style declaration of tRPC routes
• Better integration with Dependency-Injection paradigms (e.g. TSyringe)
• Improved code organization and readability

Installation

npm install trpc-decorator

Requirements

Ensure the following configurations are set in your project:

1. Install the reflect-metadata package and import it in your project's root.

2. If using TypeScript 5.0 or above, update your tsconfig.json:

   {
     "compilerOptions": {
       "experimentalDecorators": true,
       "emitDecoratorMetadata": true
     }
   }

Usage

Note: Only tRPC v10 is currently support

Setting up tRPC v10

// server/trpc.ts
import { initTRPC } from '@trpc/server';
import { useDecorators } from "trpc-decorator";
import type { ContextOf } from "trpc-decorator";

const t = initTRPC.create();

export const router = t.router;
export const publicProcedure = t.procedure;
export const authProcedure = t.procedure.use(() => {
  // Implement your authentication logic here
});

export const decorators = useDecorators({
  "public": publicProcedure,
  "auth": authProcedure,
  // Add more custom procedures as needed
});

export type contextOf = ContextOf<typeof decorators>

Define tRPC routes using decorators

// server/TestRoute.ts
import { decorators } from "./trpc";
import type { contextOf } from "./trpc";
import { z } from "zod";

@decorators.route()
export class TestRoute {
    @decorators.query("public")
    sayHello(@decorators.input(z.string()) name: string) {
        return `Hello ${name}! How are you?`;
    }

    @decorators.query("auth")
    whoAmI(@decorators.context() ctx: contextOf<"auth">) {
        return `You are ${ctx.user.name}`;
    }
}

Integrating routes

// server/_app.ts
import { router } from './trpc';
import { createTrpcDecoratorRoutes } from "trpc-decorator";
import { GeneratedRouteTypes } from "./types-generated"; // generated by `npx trpc-decorator-gen`
import { TestRoute } from './TestRoute';

const routes = createTrpcDecoratorRoutes([
    new UserRoute(),
    // In case of using IoC libraries such as TSyringe:
    // container.resolve(UserRoute)
], router) as GeneratedRouteTypes;

export const appRouter = router({
  ...routes,
  // your regular routes here
  // ...
})

// Export only the type of the router to prevent importing server code on the client
export type AppRouter = typeof appRouter;

Generating Types for Routes

To generate type definitions for your class-based routes, run:

npx trpc-decorator-gen

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

License

This project is licensed under the MIT License - see the LICENSE file for details.