Vue project error: webpack-dev-server is not an internal or external command

Error Reporting: webpack-dev-server is not an internal or external command

wrong reason:

When executing the command: npm run dev actual implementation is package.json configuration:

"dev": "webpack-dev-server --inline --progress --config build/webpack.dev.conf.js",

Equivalent: npm run webpack-dev-server --inline --progress --config build / webpack.dev.conf.js

Possible causes: No installation webpack-dev-server

Global Installation: (generally no problem globally after installation) npm install webpack-dev-server -g

Local installation: npm install webpack-dev-server --save-dev

At this time there is a new bug report

'cross-env' is not an internal or external command, operable program
or batch file.

npm install --save-dev cross-env

Error: Cannot find module 'webpack'

Solve: npm install --save-dev webpack

Error: Cannot find module 'webpack-cli/bin/config-yargs'

Solve npm install --save-dev webpack-cli

Cannot find module 'mini-css-extract-plugin'

Solve npm install --save-dev mini-css-extract-plugin

Cannot find module 'webpack-merge'

npm install --save-dev webpack-merge

Cannot find module 'vue-loader'

npm install --save-dev vue-loader

If you find it necessary to install so many dependencies, you need to immediately look at the author's instructions.

Because there may be only "npm install" on it.

Reference: https: //segmentfault.com/q/1010000006939078