Nokogiri刮擦测试失败

Question

我有以下代码：

  url       = "http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Dpets&field-keywords="
  data      = Nokogiri::HTML(open(url))
  department   = data.css('#ref_2619534011')
  @department_hash = {}
  department.css('li').drop(1).each do | department |
    department_title = department.css('.refinementLink').text
    department_count = department.css('.narrowValue').text[/[d,]+/].delete(",").to_i
    @department_hash[:department] ||= {}
    @department_hash[:department]["Pet Supplies"] ||= {}
    @department_hash[:department]["Pet Supplies"][department_title] = department_count
  end 

所以当我在模板中执行<%= @department_hash %>时，我得到的是：

{:department=>{"Pet Supplies"=>{"Birds"=>15918, "Cats"=>245418, "Dogs"=>513869, "Fish & Aquatic Pets"=>47182, "Horses"=>14774, "Insects"=>358, "Reptiles & Amphibians"=>5834, "Small Animals"=>19806}}} 

我为app.rb创建了一个规范（我使用的是Sinatra）：

app_spec.rb:

require File.dirname(__FILE__) + '/app.rb'
describe "Department" do
  it "should scrap correct string" do
    expect(@department_hash).to eq '{:department=>{"Pet Supplies"=>{"Birds"=>15918, "Cats"=>245418, "Dogs"=>513869, "Fish & Aquatic Pets"=>47182, "Horses"=>14774, "Insects"=>358, "Reptiles & Amphibians"=>5834, "Small Animals"=>19806}}}' 
  end
end

但测试失败：

  1) Department should scrap correct string
     Failure/Error: expect(@department_hash).to eq '{:department=>{"Pet Supplies"=>{"Birds"=>15918, "Cats"=>245418, "Dogs"=>513869, "Fish & Aquatic Pets"=>47182, "Horses"=>14774, "Insects"=>358, "Reptiles & Amphibians"=>5834, "Small Animals"=>19806}}}'
       expected: "{:department=>{"Pet Supplies"=>{"Birds"=>15918, "Cats"=>245418, "Dogs"=>513869, "Fish & Aquatic Pets"=>47182, "Horses"=>14774, "Insects"=>358, "Reptiles & Amphibians"=>5834, "Small Animals"=>19806}}}"
            got: nil
       (compared using ==)
     # ./app_spec.rb:5:in `block (2 levels) in <top (required)>'

编辑：

我试过这个：

expect（@department_hash[：department]["宠物用品"].keys）.to eq'["鸟"，"猫"，"狗"，"鱼和水生宠物"，"马"，"昆虫"，"爬行动物和两栖动物"，"小动物"]

但测试也失败了：

2） 部门应报废正确的钥匙失败/错误：expect（@department_hash[：department]["Pet Supplies"].keys）.to eq'["Birds"、"Cats"、"Dogs"、"Fish&Aquatic"宠物"，"马"，"昆虫"，"爬行动物和；两栖动物"、"小动物"无方法错误：中未定义的方法[]' for nil:NilClass # ./app_spec.rb:9:in块（2级）

原因可能是什么？

Answer 1

@department_hash未在测试范围内定义。

如果你举一个简单的例子：

require 'rspec/autorun'
@department_hash = 2
puts defined?(@department_hash)
#=> "instance-variable"
describe "Department" do
  it "should scrap correct string" do
        puts defined?(@department_hash)
        #=> "" (ie not defined)
    end
end

您可以看到@department_hash是在main中定义的，但它不是在测试中定义的。

您需要在测试范围内运行应用程序代码。例如，将代码移动到测试中，@department_hash将不再为零。

require 'rspec/autorun'
require 'nokogiri'
require 'open-uri'
describe "Department" do
  it "should scrap correct string" do
    url       = "http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Dpets&field-keywords="
    data      = Nokogiri::HTML(open(url))
    department   = data.css('#ref_2619534011')
    @department_hash = {}
    department.css('li').drop(1).each do | department |
      department_title = department.css('.refinementLink').text
      department_count = department.css('.narrowValue').text[/[d,]+/].delete(",").to_i
      @department_hash[:department] ||= {}
      @department_hash[:department]["Pet Supplies"] ||= {}
      @department_hash[:department]["Pet Supplies"][department_title] = department_count
    end       
    expect(@department_hash).to eq({:department=>{"Pet Supplies"=>{"Birds"=>17556, "Cats"=>245692, "Dogs"=>516246, "Fish & Aquatic Pets"=>47424, "Horses"=>15062, "Insects"=>358, "Reptiles & Amphibians"=>5835, "Small Animals"=>19836}}})
  end
end

请注意，您的测试应该是eq(hash)而不是eq 'hash'（即，您希望将哈希值而不是字符串与哈希值进行比较。

更新-提取到类的代码：

如果要在其他地方重复使用，那么将应用程序代码移动到测试中是不理想的。相反，最好为应用程序代码创建一个方法或类，然后从测试中调用该代码。

require 'rspec/autorun'
require 'nokogiri'
require 'open-uri'
# This class could be placed in your app.rb  
class DepartmentScraper
  def scrape_page()
    url       = "http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Dpets&field-keywords="
    data      = Nokogiri::HTML(open(url))
    department   = data.css('#ref_2619534011')
    @department_hash = {}
    department.css('li').drop(1).each do | department |
      department_title = department.css('.refinementLink').text
      department_count = department.css('.narrowValue').text[/[d,]+/].delete(",").to_i
      @department_hash[:department] ||= {}
      @department_hash[:department]["Pet Supplies"] ||= {}
      @department_hash[:department]["Pet Supplies"][department_title] = department_count        
    end
    return @department_hash
  end
end
describe "Department" do
  it "should scrap correct string" do
    department_hash = DepartmentScraper.new.scrape_page()
    expect(department_hash).to eq({:department=>{"Pet Supplies"=>{"Birds"=>17556, "Cats"=>245692, "Dogs"=>516246, "Fish & Aquatic Pets"=>47424, "Horses"=>15062, "Insects"=>358, "Reptiles & Amphibians"=>5835, "Small Animals"=>19836}}})
  end
end