Stimulus/Capybara helper to ensure that the stimulus application loaded all controllers

stimulus_helper.rb

module StimulusHelper
  CouldNotLoadStimulus = Class.new(StandardError) do
    def initialize(missing_controllers)
      super("Could not load all controllers. missing: #{missing_controllers}")
    end
  end

  # Reads the list of controllers from the filesystem
  APPLICATION_CONTROLLERS = Dir[Rails.root.join('app/javascript/controllers/*')].map do |path|
    File.basename(path).gsub('_controller.js', '').gsub('_', '-')
  end - ['application.js', 'index.js']

  def ensure_stimulus_is_ready
    tries = 0

    begin
      missing_controllers = APPLICATION_CONTROLLERS - loaded_controllers

      raise CouldNotLoadStimulus, missing_controllers if missing_controllers.any?
    rescue CouldNotLoadStimulus => e
      tries += 1
      raise e if tries > 3

      sleep 0.2
      retry
    end
  end
end