easy-going-rails/app/controllers/flash_controller.rb

# interaction with the flash message
class FlashController < ApplicationController
  def index; end

  def turbo_notice
    flash[:notice] = 'From Turbo'
    flash[:alert] = 'Alert Turbo'
    render turbo_stream: flash_stream
  end

  def redirect_with_notice
    redirect_to flash_path, notice: build_message(:notice)
  end

  def redirect_with_alert
    redirect_to flash_path, alert: build_message(:alert)
  end

  private

  def build_message(type_of_message)
    session[:flash_iteration] = session[:flash_iteration].to_i + 1
    "this is #{type_of_message} ##{session[:flash_iteration]}"
  end
end