$ is not defined when installing jQuery in Rails via Webpack

The code in config/webpack/environment.js should look like this:

environment.plugins.prepend('Provide',
  new webpack.ProvidePlugin({
    $: 'jquery/src/jquery',
    jQuery: 'jquery/src/jquery'
  })
)

see also https://www.botreetechnologies.com/blog/introducing-jquery-in-rails-6-using-webpacker

I've got what's missing.

In app/javascript/packs/application.js forgot to declare:

window.jQuery = $;
window.$ = $;

So jQuery keywords could be picked up.

Related