Rails - use reflection to get all declared ActiveRecord associations between entities

reflect_on_associations.rb

Rails.application.eager_load!
data = ActiveRecord::Base.descendants.map{|klass| [klass, klass.reflections.map{|k, v| [v.class.name, k]}] }
 
data.map{|klass, relations| relations.map{|k, v| "#{klass} #{k.gsub('ActiveRecord::Reflection::', '').gsub('Reflection', '').underscore.humanize.downcase} #{v}"} }.flatten