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

因此，当我在模板中执行此<%= @department_hash %>时，我得到了这个：

{: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（我正在使用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

但测试失败了：

  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)>'

修改

我试过了：

期待（@department_hash [：部门] [“宠物用品”]。钥匙）.to eq '[“鸟类”，“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）部门应该废弃正确的密钥失败/错误：期待（@department_hash [：department] [“Pet Supplies”]。键）.to eq'[“Birds”，“Cats”，“Dogs”，“Fish＆amp; Aquatic 宠物“，”马“，”昆虫“，”爬行动物＆amp;两栖动物“，”小动物“]' NoMethodError： '
中的未定义方法[]' for nil:NilClass # ./app_spec.rb:9:in块（2级）

可能是什么原因？

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在main中定义，但未在测试中定义。

您需要在测试范围内运行您的应用代码。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：

将应用程序代码移入测试并不理想，如果它可以在其他地方重用。相反，为应用程序代码创建方法或类，然后从测试中调用该代码可能更好。

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

Nokogiri刮削试验失败了吗？

1 个答案: