Rails6での before_render

render メソッドを、run_callbacks で包むだけのモンキーパッチ

# frozen_string_literal: true

module BeforeRender
  extend ActiveSupport::Concern

  included do
    define_callbacks :render
    prepend RenderPatch
  end

  module RenderPatch
    def render(*options, &block)
      run_callbacks(:render) do
        super(*options, &block)
      end
    end
  end

  class_methods do
    def before_render(*names, &block)
      _insert_callbacks(names, block) do |name, options|
        set_callback(:render, :before, name, options)
      end
    end
  end
end