Question

我的问题的主旨如下： -

我正在Ruby中编写一个Mocha模拟器，用于下面表示为“post_to_embassy”的方法。出于描述问题的目的，实际方法的作用并不是我们真正关心的问题。但是我需要模拟来返回一个动态值。下面的proc'＆amp; prc'正确执行以代替实际方法。但是Mocha中的“with”方法只允许返回布尔值。所以下面的代码输出nil。我需要它来输出通过orderInfoXml传递的值。有谁知道我可以使用的替代方法？

require 'rubygems'
require 'mocha'
include Mocha::API

class EmbassyInterface 
  def post_to_embassy(xml)
    puts "This is from the original class:-"
    puts xml
    return xml
  end
end

orderInfoXml = "I am THE XML"

mock = EmbassyInterface.new
prc = Proc.new do |orderXml| 
  puts "This is from the mocked proc:-"
  puts orderXml
  orderXml
end

mock.stubs(:post_to_embassy).with(&prc)
mock_result = mock.post_to_embassy(orderInfoXml)
p mock_result
#p prc.call("asd")

输出： -

This is from the mocked proc:-
I am THE XML
nil

Answer 1

我不确定是否有一个完美的方法。但为了让生活变得更轻松，而不是将每个可能的响应（如另一个答案所述），你可以使用Mocha的yields方法。

require "rubygems"
require "mocha"

include Mocha::API

class EmbassyInterface

  def post_to_embassy(xml)
    puts "This is form the original class:-"
    puts xml
    xml
  end
end

order_info_xml = "I am the xml"

mock = EmbassyInterface.new

prc = Proc.new do |order_xml|
  puts "This is from the mocked proc:-"
  puts order_xml
  order_xml
end

mock.stubs(:post_to_embassy).yields prc

prc_return = nil

mock.post_to_embassy { |value| prc_return = value.call("hello world") }
puts prc_return

mock.post_to_embassy { |value| prc_return = value.call("foo") }
puts prc_return

输出：

This is from the mocked proc:-
hello world
hello world

This is from the mocked proc:-
foo
foo

这将要求您指定prc的返回值，并且它不完全漂亮（imo）。但是，你不必把每个期望都排除在外，这会给你很大的自由。

Answer 2

通常，在测试中指定显式返回值通常会更好。如果你引入单独的逻辑来确定返回什么值，它往往会使测试难以理解并且难以维护。

我建议您使用Expectation#with和合适的ParameterMatchers来明确定义不同参数值的返回值，或使用StateMachine功能。

Answer 3

摩卡似乎不支持这一点。将其添加到test_helper.rb：

void Main()
{
    var schedules = new[]{
        new Schedule() { IsOn = true, DayOfWeek = DayOfWeek.Monday, TimeFrom = 540, TimeTo = 1080 },
        new Schedule() { IsOn = false, DayOfWeek = DayOfWeek.Monday, TimeFrom = 780, TimeTo = 840 }
    };


    var byDay = schedules.GroupBy(i => i.DayOfWeek)
                .Select(i =>
                {
                    var times = i.Select(t => string.Format(@"{0:hh\:mm}-{1:hh\:mm}", TimeSpan.FromMinutes(t.TimeFrom), TimeSpan.FromMinutes(t.TimeTo)));
                    return string.Format("{0}: {1}", i.Key, string.Join("; ", times));
                });

    foreach (var day in byDay)
    {
        Console.WriteLine(byDay);
    }
}

public class Schedule
{
    public bool IsOn { get; set; }
    public DayOfWeek DayOfWeek { get; set; }
    public short TimeFrom { get; set; } // store time as amount of minutes since start of day
    public short TimeTo { get; set; } // store time as amount of minutes since start of day
}

然后用以下代码替换测试的最后4行：

# Replace klass's method_name with method_implementation
def stub_replace(klass, method_name, &method_implementation)
  klass.singleton_class.send(:alias_method, "#{method_name}_mock_backup", method_name)
  klass.define_singleton_method(method_name, method_implementation)
end

def undo_stub_replace(klass, method_name)
  klass.singleton_class.send(:alias_method, method_name, "#{method_name}_mock_backup")
end

Answer 4

我还没有找到一种方法来使模拟方法的输出完全动态化，但是如果你有一个有限的，已知数量的输入，你可以让输出正常工作。

require 'rubygems'
require 'mocha'
include Mocha::API

class EmbassyInterface 
  def post_to_embassy(xml)
    "original: #{xml}"
  end
end

to_mock = EmbassyInterface.new
orderInfoXml1 = "I am the first XML."
orderInfoXml2 = "I am the second XML."

p to_mock.post_to_embassy(orderInfoXml1)

prc = Proc.new do |xml| 
  "mocked: #{xml}"
end
to_mock.stubs(:post_to_embassy).with(orderInfoXml1).returns(prc.call(orderInfoXml1))
to_mock.stubs(:post_to_embassy).with(orderInfoXml2).returns(prc.call(orderInfoXml2))

p to_mock.post_to_embassy(orderInfoXml1)
p to_mock.post_to_embassy(orderInfoXml2)
p to_mock.post_to_embassy(orderInfoXml1)

输出：

"original: I am the first XML."
"mocked: I am the first XML."
"mocked: I am the second XML."
"mocked: I am the first XML."

如何从Ruby中的Mocha模型返回动态值

4 个答案: