yarn run dev
if you have the following error as me, see the solution.
Tapable.plugin is deprecated. Use new API on
.hooks
instead
Sol:
yarn add -D extract-text-webpack-plugin@next
https://medium.freecodecamp.org/how-to-conquer-webpack-4-and-build-a-sweet-react-app-236d721e6745
https://www.valentinog.com/blog/from-gulp-to-webpack-4-tutorial/