Provide truncate and destroy_all support through cequel

keyspace_helper.rb

class KeyspaceHelper
  attr_reader :connection

  def initialize
    @connection = Cequel::Record.connection
  end

  def destroy_all
    for_all_cequel_records do |clazz|
      clazz.destroy_all
    end
  end
  def truncate_all
    for_all_cequel_records do |clazz|
      truncate_table(clazz)
    end
  end

  private

  def for_all_cequel_records
    Dir.glob(Rails.root.join('app', 'models', '**', '*.rb')).each do |file|
      watch_stack = ActiveSupport::Dependencies::WatchStack.new
      watch_stack.watch_namespaces([Object])
      require_dependency(file)

      new_constants = watch_stack.new_constants
      if new_constants.empty?
        new_constants << File.basename(file, '.rb').classify
      end

      new_constants.each do |class_name|
        begin
          clazz = class_name.constantize
        rescue NameError
        else
          if clazz.ancestors.include?(Cequel::Record)
            yield(clazz) if block_given?
          end
        end
      end
    end

  end

  def truncate_table(clazz)
    connection.schema.truncate_table(clazz.table_name)
  end
end

For tests (RSpec/DatabaseCleaner) this is a faster version:
https://gist.github.com/elado/c95a4ffa952809865ee8

Record.descendants returns an empty list, if the models are not loaded, which is the case in my development and test environment. Collecting the created models in after_create is indeed a good idea to overcome some problems we have with destroy_all