cross-env NODE_ENV=development webpack [Fixed]

In Laravel 5.4 there is no gulpfile.js file because everything's moved into the web pack now, the first time I ran

$npm run dev

I encountered this error.

cross-env NODE_ENV=development webpack --progress --hide-modules --config=node_modules/laravel-mix/setup/webpack.config.js

Fix by installing the latest Node Js

sudo npm cache clean -f 
sudo npm install -g n 
sudo n stable

Run this again to gulp your files

$npm run dev