Webpack - webpack-dev-server: command not found

Okay, it was easy:

npm install webpack-dev-server -g

What confused me that I did not need that at first, probably things changed with a new version.

FYI, to access any script via command-line like you were trying, you need to have the script registered as a shell-script (or any kind of script like .js, .rb) in the system like these files in the the dir /usr/bin in UNIX. And, system must know where to find them. i.e. the location must be loaded in $PATH array.

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In your case, the script webpack-dev-server is already installed somewhere inside ./node_modules directory, but system does not know how to access it. So, to access the command webpack-dev-server, you need to install the script in global scope as well.

$ npm install webpack-dev-server -g

Here, -g refers to global scope.

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However, this is not recommended way because you might face version conflicting issues; so, instead you can set a command in npm's package.json file like:

  "scripts": {
    "start": "webpack-dev-server -d --config webpack.dev.config.js --content-base public/ --progress --colors"
   }

This setting will let you access the script you want with simple command

$ npm start

or

$ yarn start

So short to memorize and play. And, npm knows the location of the module webpack-dev-server.