Understanding scoped packages

For as long as I have been using Ember I have become accustomed to my IDE (WebStorm) warning me that I am importing from “Module not installed”.

For example if I create a new route I end up with:

import Route from '@ember/routing/route';

export default Route.extend({

The import Route line will be underlined with a warning.

In another example, if I import jquery as given in the docs, import $ from 'jquery'; , I get the same error.

I remembered seeing “@ember/jquery” in my package.json file so I changed the line to import $ from '@ember/jquery'; and the warning went away, but that must be something else because that doesn’t work when built.

I did find an @ember directory in node_modules, and @ember/jquery does exist, but @ember/routing does not.

My ember app builds fine so @ember/routing must exist somewhere, I just don’t understand where. I would like to know if WebStorm is deficient in locating these modules, if I have misconfigured something in my IDE or if there is something unique about Ember that prevents an IDE from being aware of the modules.