Reusable eager loading with rails

discussion.rb

class Discussion < ActiveRecord::Base
  scope :with_includes, -> { includes(:comments, :category) }
  scope :by_recency, -> { order('created_at DESC') }
  scope :visible, -> { where(hidden: false) }
end

discussions_controller.rb

class DiscussionsController < ApplicationController
  def index
    @discussions = Discussion.with_includes.visible.by_recency
  end
end