require_relative '../model_helpers'

module Gitlab
  module Styles
    module Rubocop
      module Cop
        # Cop that prevents the use of `dependent: ...` in ActiveRecord models.
        class ActiveRecordDependent < RuboCop::Cop::Cop
          include ModelHelpers

          MSG = 'Do not use `dependent: to remove associated data, ' \
            'use foreign keys with cascading deletes instead'.freeze

          METHOD_NAMES = [:has_many, :has_one, :belongs_to].freeze

          def on_send(node)
            return unless in_model?(node)
            return unless METHOD_NAMES.include?(node.children[1])

            node.children.last.each_node(:pair) do |pair|
              key_name = pair.children[0].children[0]

              add_offense(pair, :expression) if key_name == :dependent
            end
          end
        end
      end
    end
  end
end
