uglifyjs-webpack-plugin压缩不能用

uglifyjs-webpack-plugin压缩js提示，找不多该模块

想在webpack打包时把文件进行压缩，一直提示找不到该模块‘uglifyjs-webpack-plugin’

E:\Web\webpack\node_modules\[email protected]@webpack-cli\bin\cli.js:231
                                throw err;
                                ^

Error: Cannot find module 'uglifyjs-webpack-plugin'

总结以下几点坑

1. 项目名不能是webpack

2. 初始化项目cnpm init

3. 项目名不能是webpack

4. 在项目里面安装webpack,和webpack-cli,(我都是全局安装的，不全局安装webpack，在控制台输入webpack是没用的)

5. cnpm install webpack webpack-cli --save-dev

6. 在项目里面安装uglifyjs-webpack-plugin

7. cnpm install uglifyjs-webpack-plugin --save-dev

 "devDependencies": {
    "uglifyjs-webpack-plugin": "^2.1.2",
    "webpack": "^4.29.6",
    "webpack-cli": "^3.3.0"
  },
  "name": "webpk",