shared_examples 'lists list service' do
  context 'when the board has a backlog list' do
    let!(:backlog_list) { create(:backlog_list, board: board) }

    it 'does not create a backlog list' do
      expect { service.execute(board) }.not_to change(board.lists, :count)
    end

    it "returns board's lists" do
      expect(service.execute(board)).to eq [backlog_list, list, board.closed_list]
    end
  end

  context 'when the board does not have a backlog list' do
    it 'creates a backlog list' do
      expect { service.execute(board) }.to change(board.lists, :count).by(1)
    end

    it "returns board's lists" do
      expect(service.execute(board)).to eq [board.backlog_list, list, board.closed_list]
    end
  end
end