lib/action_view/helpers/debug_helper.rb
# frozen_string_literal: true require "action_view/helpers/tag_helper" module ActionView # = Action View Debug Helper # # Provides a set of methods for making it easier to debug Rails objects. module Helpers # :nodoc: module DebugHelper include TagHelper # Returns a YAML representation of +object+ wrapped with <pre> and </pre>. # If the object cannot be converted to YAML using +to_yaml+, +inspect+ will be called instead. # Useful for inspecting an object at the time of rendering. # # @user = User.new({ username: 'testing', password: 'xyz', age: 42}) # debug(@user) # # => # <pre class='debug_dump'>--- !ruby/object:User # attributes: # updated_at: # username: testing # age: 42 # password: xyz # created_at: # </pre> def debug(object) Marshal.dump(object) object = ERB::Util.html_escape(object.to_yaml) content_tag(:pre, object, class: "debug_dump") rescue # errors from Marshal or YAML # Object couldn't be dumped, perhaps because of singleton methods -- this is the fallback content_tag(:code, object.inspect, class: "debug_dump") end end end end