ruby - RSpec 测试包含 gets.chomp 的方法

Question

如何设计 RSpec 测试以将 gets.chomp 方法分配给实例变量？

def choose
    puts "Please enter the type you want:"
    @type = gets.chomp
    puts "Thank you, now please enter how many of those you want:"
    @quantity = gets.chomp
end

Answer 1

您可以为此使用 stub /模拟。但主要问题是:您将 def choose 放在哪里？这很重要，因为我会在某些对象上 stub 它的调用。

假设您在 class Item 中有这个方法:

class Item
  def choose
    puts "Please enter the type you want:"
    @type = gets.chomp
    puts "Thank you, now please enter how many of those you want:"
    @quantity = gets.chomp
  end
end

然后我将能够 stub gets 和 chomp 调用来模拟用户的输入:

RSpec.describe Item do
  describe '#choose' do
    before do
      io_obj = double
      expect(subject)
        .to receive(:gets)
        .and_return(io_obj)
        .twice
      expect(io_obj)
        .to receive(:chomp)
        .and_return(:type)
      expect(io_obj)
        .to receive(:chomp)
        .and_return(:quantity)
    end

    it 'sets @type and @quantity according to user\'s input' do
      subject.choose

      expect(subject.instance_variable_get(:@type)).to eq :type
      expect(subject.instance_variable_get(:@quantity)).to eq :quantity
    end
  end
end