All my Stimulus controllers are unregistered, even though they aren't

[Burgestrand]

(this issue is written in tandem with @marcoroth at Baltic Ruby!)

Here's my application.js:

/* eslint no-console:0 */

import { Application } from "@hotwired/stimulus"
import { definitionsFromContext } from "@hotwired/stimulus-webpack-helpers"
import CheckboxSelectAll from "stimulus-checkbox-select-all"

const application = Application.start()

const context = require.context("./controllers", true, /.js/)
application.load(definitionsFromContext(context))

application.register("checkbox-select-all", CheckboxSelectAll)

The problem is that the Stimulus application and the control index file are in the same file? Or that the require.context doesn't expand properly.

We did separate this into controllers/application.js and controllers/index.js, but that didn't change the outcome.