Puffing Billy with Poltergeist error: "rack-test requires a rack application, but none was given"

Question

使用 Puffing Billy instructions for rspec with capybara 我创建了一个简单的测试来存根使用 :poltergeist_billy 驱动程序的请求导致错误：

ArgumentError:
        rack-test requires a rack application, but none was given
      # /home/resrev/.rvm/gems/ruby-2.3.1/gems/capybara-2.4.4/lib/capybara/rack_test/driver.rb:16:in `initialize'
      # /home/resrev/.rvm/gems/ruby-2.3.1/gems/capybara-2.4.4/lib/capybara.rb:372:in `new'
      # /home/resrev/.rvm/gems/ruby-2.3.1/gems/capybara-2.4.4/lib/capybara.rb:372:in `block in <top (required)>'
      # /home/resrev/.rvm/gems/ruby-2.3.1/gems/capybara-2.4.4/lib/capybara/session.rb:79:in `driver'
      # /home/resrev/.rvm/gems/ruby-2.3.1/gems/capybara-2.4.4/lib/capybara/session.rb:227:in `visit'
      # /home/resrev/.rvm/gems/ruby-2.3.1/gems/capybara-2.4.4/lib/capybara/dsl.rb:51:in `block (2 levels) in <module:DSL>'
      # ./spec/scraypa_spec.rb:52:in `block (4 levels) in <top (required)>'

使用此代码：

spec/spec_helper.rb

require "bundler/setup"
require "scraypa"
require 'billy/capybara/rspec'

RSpec.configure do |config|
  # Enable flags like --only-failures and --next-failure
  config.example_status_persistence_file_path = ".rspec_status"

  config.expect_with :rspec do |c|
    c.syntax = :expect
  end

  config.include Capybara::DSL
end

spec/my_spec.rb:

it "should utilise capybara to download web content" do
  #Capybara.current_driver = :poltergeist_billy
  Capybara.javascript_driver = :poltergeist_billy
  proxy.stub('http://www.google.com/')
        .and_return(:text => "test response")
  visit "http://www.google.com/"
  expect(page.text).to eq('test response')
end

在四处挖掘时，我发现了一个使用 Capybara.current_driver = :poltergeist_billy 的示例（我在上面的测试中已将其注释掉），如果我取消注释该代码，则会收到此错误：

Cliver::Dependency::NotFound:
        Could not find an executable ["phantomjs"] on your path.
      # /home/resrev/.rvm/gems/ruby-2.3.1/gems/cliver-0.3.2/lib/cliver/dependency.rb:143:in `raise_not_found!'
      # /home/resrev/.rvm/gems/ruby-2.3.1/gems/cliver-0.3.2/lib/cliver/dependency.rb:116:in `detect!'
      # /home/resrev/.rvm/gems/ruby-2.3.1/gems/cliver-0.3.2/lib/cliver.rb:24:in `detect!'
      # /home/resrev/.rvm/gems/ruby-2.3.1/gems/poltergeist-1.9.0/lib/capybara/poltergeist/client.rb:36:in `initialize'
      # /home/resrev/.rvm/gems/ruby-2.3.1/gems/poltergeist-1.9.0/lib/capybara/poltergeist/client.rb:14:in `new'
      # /home/resrev/.rvm/gems/ruby-2.3.1/gems/poltergeist-1.9.0/lib/capybara/poltergeist/client.rb:14:in `start'
      # /home/resrev/.rvm/gems/ruby-2.3.1/gems/poltergeist-1.9.0/lib/capybara/poltergeist/driver.rb:42:in `client'
      # /home/resrev/.rvm/gems/ruby-2.3.1/gems/poltergeist-1.9.0/lib/capybara/poltergeist/driver.rb:25:in `browser'
      # /home/resrev/.rvm/gems/ruby-2.3.1/gems/poltergeist-1.9.0/lib/capybara/poltergeist/driver.rb:95:in `visit'
      # /home/resrev/.rvm/gems/ruby-2.3.1/gems/capybara-2.4.4/lib/capybara/session.rb:227:in `visit'
      # /home/resrev/.rvm/gems/ruby-2.3.1/gems/capybara-2.4.4/lib/capybara/dsl.rb:51:in `block (2 levels) in <module:DSL>'
      # ./spec/scraypa_spec.rb:52:in `block (4 levels) in <top (required)>'

我不确定从这里到哪里去或我做错了什么，有什么想法吗？谢谢。

Answer 1

这里错误较多，还是从头开始吧

您的 spec_helper.rb 或 rails_helper.rb - https://github.com/teamcapybara/capybara#setup 中没有 require capybara/rails - 这意味着 Capybara.app 不是得到设置，这就是为什么你得到 "rack-test requires a rack application" - 当然你真的不想在你当前的测试中使用 rack-test 驱动程序，#3 将处理。
Capybara 已将 Capybara::DSL 包含在功能规范中，因此请使用功能规范，并从上面显示的 RSpec 配置中删除 include Capybara::DSL。这需要将您的规范文件放入 spec/features/my_spec.rb 并启用 RSpec 配置以按目录确定测试类型，或者手动指定测试是功能规范
```
feature "should utilise capybara to download web content" do
  ...
end
```
或
```
it "should utilise capybara to download web content", type: :feature do
  ...
end
```
您的测试实际上使用的是 rack_test 驱动程序，而不是 poltergeist-billy 驱动程序。这是因为您在测试中设置 Capybara.javascript_driver 。它需要在测试之前设置，然后用元数据标记测试以告诉它使用特定的驱动程序。这里有两个选项，要么在 spec_helper.rb 中设置 Capybara.javascript_driver = :poltergeist_billy，然后指定 :js metadata
```
 feature "should utilise capybara to download web content", :js do
   ...
 end
```
或指定 :driver 元数据以识别用于给定测试的驱动程序
```
feature "should utilise capybara to download web content", driver: :poltergeist_billy do 
  ... 
end
```
当指定将 poltergeist 与 billy 一起使用时，您需要在路径中安装 PhantomJS（Poltergeist 需要）。如果将 OSX 与自制软件一起使用，您可以 brew install phantomjs - 在其他系统上，您需要下载最新版本的 PhantomJS 并将其放在 PATH
expect(page.text).to eq('test response')。这是使用 Capybara 进行文本匹配的糟糕方法。 eq 没有 waiting/retrying 行为，因为当 Capybaras 方法 return 会导致不稳定的测试时，操作无法保证完成。相反，请使用 Capybara 提供的匹配器。如果您对子字符串匹配没问题，请执行

expect(page).to have_text('test_response')

如果需要完全匹配

expect(page).to have_text('test_response', exact: true)

Puffing Billy with Poltergeist error: "rack-test requires a rack application, but none was given"

Puffing Billy with Poltergeist error: "rack-test requires a rack application, but none was given"

ruby-on-rails

rspec

capybara

poltergeist