class RuboCop::Cop::Rails::DuplicateAssociation

def on_class(class_node)
  return unless active_record?(class_node.parent_class)
  association_nodes = association_nodes(class_node)
  duplicated_association_name_nodes(association_nodes).each do |name, nodes|
    register_offense(name, nodes, MSG)
  end
  duplicated_class_name_nodes(association_nodes).each do |class_name, nodes|
    register_offense(class_name, nodes, MSG_CLASS_NAME)
  end
end