Node.js ও TypeScript

# tsx ব্যবহারে সরাসরি TypeScript run
npm install -D typescript tsx @types/node

# package.json
"scripts": {
  "dev": "tsx watch src/index.ts",
  "build": "tsc",
  "start": "node dist/index.js"
}

interface AppConfig {
  port: number;
  databaseUrl: string;
}

function readConfig(): AppConfig {
  return {
    port: Number(process.env.PORT ?? 3000),
    databaseUrl: process.env.DATABASE_URL ?? "mongodb://localhost",
  };
}

export const config = readConfig();

import express from "express";


const app = express();
app.use(express.json());

interface Todo {
  id: number;
  title: string;
  done: boolean;
}

const todos: Todo[] = [];

app.get("/todos", (_req: Request, res: Response<Todo[]>) => {
  res.json(todos);
});

app.listen(3000, () => {
  console.log("সার্ভার চলছে :3000");
});

import type { Request, Response, NextFunction } from "express";

// async handler টাইপ
type AsyncHandler = (req: Request, res: Response, next: NextFunction) => Promise<void>;

const wrapAsync =
  (handler: AsyncHandler) =>
  async (req: Request, res: Response, next: NextFunction) => {
    try {
      await handler(req, res, next);
    } catch (error) {
      next(error);
    }
  };

app.get(
  "/users",
  wrapAsync(async (req, res) => {
    const data = await getUsers();
    res.json(data);
  }),
);