ruby 作业订单列表中的单个依赖项在其结果上重复

Question

我有一份工作清单，并为以下问题编写了规范，其中列表中的一项依赖于另一项。我得到的结果是两次返回列表项 c。题目如下：

Given the following job structure:

a =>
b => c
c =>
The result should be a sequence that positions c before b, containing all three jobs abc.

我很困惑，因为我的测试失败如下

  1) JobsList should return ordered multiple jobs with the dependency if multiple jobs with single dependency were supplied
     Failure/Error: expect(JobsList.sequence({'a' => nil, 'b' => 'c', 'c' => nil})).to eq ['a', 'c', 'b']

       expected: ["a", "c", "b"]
            got: ["a", "c", "c", "b"]

       (compared using ==)

我在这里不知所措，我做错了什么，有人可以提供任何建议吗？

jobs_list_spec

require 'jobs_list'

describe JobsList do

    it "should return an empty sequence of jobs if a blank hash was supplied" do 
        expect(JobsList.sequence({})).to eq []      
    end


    it "should return an single job character if a single jobs was supplied" do 
        expect(JobsList.sequence({'a' => nil})).to eq ['a']     
    end

    it "should return multiple jobs characters if a multiple jobs were supplied" do 
        expect(JobsList.sequence({'a' => nil, 'b' => nil, 'c' => nil})).to eq ['a', 'b', 'c']       
    end

    it "should return ordered multiple jobs with the dependency if multiple jobs with single dependency were supplied" do 
        expect(JobsList.sequence({'a' => nil, 'b' => 'c', 'c' => nil})).to eq ['a', 'c', 'b']       
    end

jobs_list.rb

class JobsList
    def self.sequence(jobs={})
        grouped_jobs = jobs.group_by{|k, v| v}
        grouped_jobs.map do |k,v|
            array = []
            if k 
                array = array + [k]
            end
            array = array + v.map{|a| a[0]}
        end.flatten
    end
end

Answer 1

一些可能有帮助的建议：

尝试修改class的接口或将逻辑移动到class的实例而不是class方法中，因为这会使其难以使用状态。
其次尝试将功能拆分为具有表现力名称的微小 classes，这将帮助您更轻松地思考逻辑。

如果您想保留当前基于 class 的界面，请考虑以下内容来构建您的 class 方法：

def self.sequence(jobs)
  JobList.new(jobs).sequence
end

现在，您可以将逻辑转移到实例方法中；并不是说 class 方法之间不能共享实例。但这种方法可能更容易推理出来。

如果你完全卡住了，看看我解决的 Ordered Job Kata 中的逻辑是如何分解的。

Answer 2

我不确定我是否遇到了你的问题，但你可以试试这段代码。

class JobsList
  def self.sequence(jobs={})
    jobs.to_a.flatten.uniq.compact
  end
end

Answer 3

    def self.sequence(jobs={})
    puts 'hi'
    grouped_jobs = jobs.group_by{|k, v| v}
    grouped_jobs.map do |k,v|
        array = []
        if k 
            array = array + [k]
        end
        array = array + v.map{|a| a[0]}
    end.flatten.uniq.compact
end

ruby 作业订单列表中的单个依赖项在其结果上重复

single dependency in ruby job order list is duplicating on its result

ruby

rspec