Upgrade to Stimulus 3 recommandations

upgrade.md

To upgrade to Stimulus 3.0 and minimize the side effects of the npm package name change here is my suggestion

# add the proxy package
yarn add stimulus

# add the new @hotwired/stimulus package
yarn add @hotwired/stimulus

# add the dedicated package for the Webpack helpers
yarn add @hotwired/stimulus-webpack-helpers

Update your webpack imports

-import { Application } from 'stimulus'
-import { definitionsFromContext } from 'stimulus/webpack-helpers'
+import { Application } from '@hotwired/stimulus'
+import { definitionsFromContext } from '@hotwired/stimulus-webpack-helpers'

and in your controllers find and replace

-import { Controller } from 'stimulus'
+import { Controller } from '@hotwired/stimulus'

If you are using Webpacker 6, remove the loose: true option from Babel until rails/webpacker#3153 is resolved.

{
  useBuiltIns: 'entry',
  corejs: '3.8',
  modules: 'auto',
  bugfixes: true,
- loose: true,
  exclude: ['transform-typeof-symbol']
}