if ActiveRecord::VERSION::MINOR >= 1
  describe "arel-mysql-index-hint" do
    describe "#includes" do
      context "when single index" do
        subject do
          User.
            includes(:microposts).
            where(microposts: {id: 1}).
            hint(microposts: {hint_type => :index_microposts_on_user_id_and_created_at}).
            to_sql.gsub(/\s+/, " ")
        end

        let(:sql) do
          "SELECT `users`.`id` AS t0_r0, `users`.`name` AS t0_r1, `users`.`email` AS t0_r2, `users`.`created_at` AS t0_r3, `users`.`updated_at` AS t0_r4, `users`.`password_digest` AS t0_r5, `users`.`remember_token` AS t0_r6, `users`.`admin` AS t0_r7, `microposts`.`id` AS t1_r0, `microposts`.`content` AS t1_r1, `microposts`.`user_id` AS t1_r2, `microposts`.`created_at` AS t1_r3, `microposts`.`updated_at` AS t1_r4 " +
          "FROM `users` " +
          "LEFT OUTER JOIN `microposts` " +
          "#{hint_type.to_s.upcase} INDEX (`index_microposts_on_user_id_and_created_at`) " +
          "ON `microposts`.`user_id` = `users`.`id` " +
          "WHERE `microposts`.`id` = 1"
        end

        let(:hint_type) { :force }

        it { is_expected.to eq sql }
      end

      context "when multiple indexes" do
        subject do
          User.
            includes(:microposts).
            where(microposts: {id: 1}).
            hint(
              users: {hint_type => :index_users_on_email},
              microposts: {hint_type => :index_microposts_on_user_id_and_created_at},
            ).
            to_sql.gsub(/\s+/, " ")
        end

        let(:sql) do
          "SELECT `users`.`id` AS t0_r0, `users`.`name` AS t0_r1, `users`.`email` AS t0_r2, `users`.`created_at` AS t0_r3, `users`.`updated_at` AS t0_r4, `users`.`password_digest` AS t0_r5, `users`.`remember_token` AS t0_r6, `users`.`admin` AS t0_r7, `microposts`.`id` AS t1_r0, `microposts`.`content` AS t1_r1, `microposts`.`user_id` AS t1_r2, `microposts`.`created_at` AS t1_r3, `microposts`.`updated_at` AS t1_r4 " +
          "FROM `users` " +
          "#{hint_type.to_s.upcase} INDEX (`index_users_on_email`) " +
          "LEFT OUTER JOIN `microposts` " +
          "#{hint_type.to_s.upcase} INDEX (`index_microposts_on_user_id_and_created_at`) " +
          "ON `microposts`.`user_id` = `users`.`id` " +
          "WHERE `microposts`.`id` = 1"
        end

        let(:hint_type) { :force }

        it { is_expected.to eq sql }
      end
    end
  end
end