"name": "webpack-study1",
"version": "1.0.0",
"main": "index.js",
"scripts": {
"test": "echo \"Error: no test specified\" && exit 1",
"dev": "webpack-dev-server --open --port 3000 --hot",
"bulid": "webpack --mode production",
"start": "--mode development",
"build": "--mode production"

npm run test
npm run dev

.....

package.json 中 scripts