npm init -y
npm init -g typescript
tsc --init
"rootDir": "./src" /* Specify the root folder within your source files. */,
...
"outDir": "./build" /* Specify an output folder for all emitted files. */,
npm i nodemon concurrently
nodemon : 코드 변경 시, 서버 자동 재실행 concurrently : 동시에 여러 명령을 실행
"scripts": {
"start:build": "tsc -w",
"start:run": "nodemon build/index.js",
"start": "concurrently npm:start:*"
},