วิธีการตั้งค่า TypeScript กับ Node.js

mkdir typescript-node
cd typescript-node
npm init -y

npm i -D typescript ts-node nodemon

ืnpx tsc --init

{
  "compilerOptions": {
-    "target": "es5"
+    "target": "es6" /* กำหนดว่าให้แปลงเป็น js version อะไร */,
    "module": "commonjs" /* กำหนดว่าจะใช้ module แบบไหน */,
+    "moduleResolution": "node" /* บอกใช้กับ Node.js */,
    "esModuleInterop": true /* อนุญาติให้ complie ES6 module เป็น commonjs*/,
    "strict": true /* เปิดใช้ strict type-checking options*/,
+    "outDir": "./dist" /* ระบุโฟลเดอร์ output (JavaScript) */,
+    "rootDir": "./src" /* ระบุโฟลเดอร์ sourcecode (TypeScript) */
  }
}

"scripts": {
  "dev": "nodemon",
  "build": "tsc --project ./"
},

{
  "watch": ["src"],
  "ext": "ts",
  "ignore": ["src/**/*.spec.ts"],
  "exec": "ts-node ./src/index.ts"
}

const geeting = (name: string) => {
  console.log(`Hello ${name} from TypeScript.`);
};

geeting('Ball');

> typescript-node@1.0.0 dev D:\workspaces\playgounds\typescript-node
> nodemon

[nodemon] 2.0.7
[nodemon] to restart at any time, enter `rs`
[nodemon] watching path(s): src\**\*
[nodemon] watching extensions: ts
[nodemon] starting `ts-node ./src/index.ts`
Hello Ball from TypeScript.
[nodemon] clean exit - waiting for changes before restart

[nodemon] restarting due to changes...
[nodemon] starting `ts-node ./src/index.ts`
Hello Stamp from TypeScript.
[nodemon] clean exit - waiting for changes before restart

// dist/index.js
'use strict';
const geeting = (name) => {
  console.log(`Hello ${name} from TypeScript.`);
};
geeting('Stamp');

import express from 'express';

const app = express();

const PORT = 8000;

app.get('/', (req, res) => res.send('Express + TypeScript Server'));

app.listen(PORT, () => {
  console.log(`Server is running at http://localhost:${PORT}`);
});

npm i -D @types/node @types/express

npm run dev

> typescript-node@1.0.0 dev D:\workspaces\playgounds\typescript-node
> nodemon

[nodemon] 2.0.7
[nodemon] to restart at any time, enter `rs`
[nodemon] watching path(s): src\**\*
[nodemon] watching extensions: ts
[nodemon] starting `ts-node ./src/index.ts`
Server is running at http://localhost:8000

import express, { Application, Request, Response } from 'express';

const app: Application = express();

const PORT: number = 8000;

app.get('/', (req: Request, res: Response) => {
  res.send('Express + TypeScript Server');
});

app.listen(PORT, () => {
  console.log(`Server is running at http://localhost:${PORT}`);
});