热衷于将Capybara烘焙到新版本的Rails（5.1）cf http://weblog.rubyonrails.org/2017/2/23/Rails-5-1-beta1/
我遇到了一个问题。这是我的步骤。任何线索欢迎。
全新安装：
1.-创建一个简单的应用程序：
~$ ruby -v
ruby 2.4.0p0 (2016-12-24 revision 57164) [x86_64-linux]
~$ rails -v
Rails 5.1.0.beta1
~$ mkdir railsapps
~$ cd railsapps
~/railsapps$ rails new smoketestapp
~/railsapps$ cd smoketestapp
~/railsapps/smoketestapp$ rails generate scaffold post title:string body:text
~/railsapps/smoketestapp$ rails db:migrate
2.-运行测试
~/railsapps/smoketestapp$ cat test/system/posts_test.rb
require "application_system_test_case"
class PostsTest < ApplicationSystemTestCase
test "visiting the index" do
visit posts_url
assert_selector "h1", text: "Post"
end
end
~/railsapps/smoketestapp$ rake test TEST=test/system/posts_test.rb
Run options: --seed 55778
# Running:
...
Error:
PostsTest#test_visiting_the_index:
Selenium::WebDriver::Error::WebDriverError: Unable to find chromedriver. Please download the server from http://chromedriver.storage.googleapis.com/index.html and place it somewhere on your PATH. More info at https://github.com/SeleniumHQ/selenium/wiki/ChromeDriver.
...
1 runs, 0 assertions, 0 failures, 1 errors, 0 skips
~/railsapps/smoketestapp$
3.-好的，让我们按照错误消息（安装chromedriver）中的建议进行操作：
~/railsapps/smoketestapp$ ls /usr/bin/google-chrome
lrwxrwxrwx 1 root root 31 Mar 18 15:31 /usr/bin/google-chrome -> /etc/alternatives/google-chrome*
~/railsapps/smoketestapp$ echo $PATH
...:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:...
~/railsapps/smoketestapp$ wget https://chromedriver.storage.googleapis.com/2.28/chromedriver_linux64.zip
~/railsapps/smoketestapp$ unzip chromedriver_linux64.zip
~/railsapps/smoketestapp$ sudo cp chromedriver /usr/local/bin
~/railsapps/smoketestapp$ ls /usr/local/bin
total 7504
drwxr-xr-x 2 root root 4096 Mar 19 19:05 ./
drwxr-xr-x 10 root root 4096 Okt 12 22:42 ../
-rwxr-xr-x 1 root root 7673176 Mar 19 19:05 chromedriver*
~/railsapps/smoketestapp$
4.-好的。重试测试...
~/railsapps/smoketestapp$ rake test TEST=test/system/posts_test.rb
Run options: --seed 51574
# Running:
...
Error:
PostsTest#test_visiting_the_index:
Net::ReadTimeout: Net::ReadTimeout test/system/posts _test.rb:5:in `block in '
...
bin/rails test test/system/posts_test.rb:4
...
1 runs, 0 assertions, 0 failures, 1 errors, 0 skips
~/railsapps/smoketestapp$
不行！
在应用程序目录中运行rails -v时给出'Net :: ReadTimeout：Net :: ReadTimeout'错误消息的根本原因，给出 Selenium： ：WebDriver :: Error :: UnknownError：未知错误：Chrome无法启动：
~/railsapps/smoketestapp$ rails -v
Run options: --seed 39896
# Running:
.......E
Error:
PostsTest#test_visiting_the_index:
Selenium::WebDriver::Error::UnknownError: unknown error: Chrome failed to start: exited abnormally
(Driver info: chromedriver=2.28.455506 (18f6627e265f442aeec9b6661a49fe819aeeea1f),platform=Linux 4.8.0-41-generic x86_64)
test/system/posts_test.rb:5:in `block in <class:PostsTest>'
Error:
PostsTest#test_visiting_the_index:
Net::ReadTimeout: Net::ReadTimeout
bin/rails test test/system/posts_test.rb:4
...
~/railsapps/smoketestapp$
这是我直接从Ruby调用Selenium WebDriver时得到的结果：
~/railsapps/smoketestapp$ irb
2.4.0 :001 > require "selenium-webdriver"
=> true
2.4.0 :002 > driver = Selenium::WebDriver.for(:chrome)
Net::ReadTimeout: Net::ReadTimeout
from ~/.rvm/rubies/ruby-2.4.0/lib/ruby/2.4.0/net/protocol.rb:176:in `rbuf_fill'
from ~/.rvm/rubies/ruby-2.4.0/lib/ruby/2.4.0/net/protocol.rb:154:in `readuntil'
from ~/.rvm/rubies/ruby-2.4.0/lib/ruby/2.4.0/net/protocol.rb:164:in `readline'
from ~/.rvm/rubies/ruby-2.4.0/lib/ruby/2.4.0/net/http/response.rb:40:in `read_status_line'
from ~/.rvm/rubies/ruby-2.4.0/lib/ruby/2.4.0/net/http/response.rb:29:in `read_new'
from ~/.rvm/rubies/ruby-2.4.0/lib/ruby/2.4.0/net/http.rb:1446:in `block in transport_request'
from ~/.rvm/rubies/ruby-2.4.0/lib/ruby/2.4.0/net/http.rb:1443:in `catch'
from ~/.rvm/rubies/ruby-2.4.0/lib/ruby/2.4.0/net/http.rb:1443:in `transport_request'
from ~/.rvm/rubies/ruby-2.4.0/lib/ruby/2.4.0/net/http.rb:1416:in `request'
from ~/.rvm/rubies/ruby-2.4.0/lib/ruby/2.4.0/net/http.rb:1409:in `block in request'
from ~/.rvm/rubies/ruby-2.4.0/lib/ruby/2.4.0/net/http.rb:877:in `start'
from ~/.rvm/rubies/ruby-2.4.0/lib/ruby/2.4.0/net/http.rb:1407:in `request'
from ~/.rvm/gems/ruby-2.4.0/gems/selenium-webdriver-3.3.0/lib/selenium/webdriver/remote/http/default.rb:124:in `response_for'
from ~/.rvm/gems/ruby-2.4.0/gems/selenium-webdriver-3.3.0/lib/selenium/webdriver/remote/http/default.rb:78:in `request'
from ~/.rvm/gems/ruby-2.4.0/gems/selenium-webdriver-3.3.0/lib/selenium/webdriver/remote/http/common.rb:61:in `call'
from ~/.rvm/gems/ruby-2.4.0/gems/selenium-webdriver-3.3.0/lib/selenium/webdriver/remote/bridge.rb:669:in `raw_execute'
from ~/.rvm/gems/ruby-2.4.0/gems/selenium-webdriver-3.3.0/lib/selenium/webdriver/remote/bridge.rb:108:in `create_session'
from ~/.rvm/gems/ruby-2.4.0/gems/selenium-webdriver-3.3.0/lib/selenium/webdriver/remote/bridge.rb:71:in `initialize'
from ~/.rvm/gems/ruby-2.4.0/gems/selenium-webdriver-3.3.0/lib/selenium/webdriver/chrome/bridge.rb:52:in `initialize'
from ~/.rvm/gems/ruby-2.4.0/gems/selenium-webdriver-3.3.0/lib/selenium/webdriver/common/driver.rb:61:in `new'
from ~/.rvm/gems/ruby-2.4.0/gems/selenium-webdriver-3.3.0/lib/selenium/webdriver/common/driver.rb:61:in `for'
from ~/.rvm/gems/ruby-2.4.0/gems/selenium-webdriver-3.3.0/lib/selenium/webdriver.rb:87:in `for'
from (irb):2
from ~/.rvm/rubies/ruby-2.4.0/bin/irb:11:in `<main>'
2.4.0 :003 > exit
~/railsapps/smoketestapp$
感谢任何帮助，谢谢你
内翻
更新
发现问题，查看Selenium驱动程序的日志文件。为此，我在IRB中输入以下内容：
require "selenium-webdriver"
Selenium::WebDriver::Chrome.driver_path="/usr/local/bin/chromedriver"
Selenium::WebDriver.for :chrome, :service_log_path => "/tmp/cd.log"
driver = Selenium::WebDriver.for(:chrome)
拖尾日志文件钉住它：chrome无法启动：
~/railsapps/smoketestapp$ tail /tmp/cd.log
...
[0.247][INFO]: Launching chrome: /opt/google/chrome/google-chrome --disable-background-networking --disable-client-side-phishing-detection --disable-component-update --disable-default-apps --disable-hang-monitor --disable-prompt-on-repost --disable-web-resources --enable-logging --full-memory-crash-report --ignore-certificate-errors --load-extension=/tmp/.org.chromium.Chromium.Pdre6o/internal --logging-level=1 --metrics-recording-only --no-first-run --password-store=basic --remote-debugging-port=12264 --safebrowsing-disable-auto-update --safebrowsing-disable-download-protection --use-mock-keychain --user-data-dir=/tmp/.org.chromium.Chromium.mHJaEd data:,
[0.250][WARNING]: PAC support disabled because there is no system implementation
[20.281][INFO]: RESPONSE InitSession unknown error: Chrome failed to start: exited abnormally
~/railsapps/smoketestapp$
最后，我发现通过PuTTY远程调用chrome无法正常工作（这就是我一直在做的事情），虽然直接在VM（在终端服务器上）做同样的工作
关于PuTTY：
~$ google-chrome
[3938:3938:0320/213941.129923:ERROR:browser_main_loop.cc(279)] Gtk: cannot open display:
然而，直接在VM上工作。
不幸的是，我的幸福是短暂的，因为我遇到了另一个错误，但这是另一个故事：
irb(main):001:0> require "selenium-webdriver"
=> true
irb(main):002:0> Selenium::WebDriver::Chrome.driver_path="/usr/local/bin/chromedriver"
=> "/usr/local/bin/chromedriver"
irb(main):003:0> driver = Selenium::WebDriver.for(:chrome)
=> #<Selenium::WebDriver::Driver:0x59d7c889a916c6b8 browser=:chrome>
irb(main):004:0> driver.navigate.to("http://www.google.com")
Selenium::WebDriver::Error::UnknownError: unknown error: Runtime.executionContextCreated has invalid 'context': {"auxData":{"frameId":"10797.1","isDefault":true},"id":1,"name":"","origin":"://"}
(Session info: chrome=57.0.2987.110)
(Driver info: chromedriver=2.4.226074,platform=Linux 4.8.0-41-generic x86_64)
from ~/.rvm/rubies/ruby-2.4.0/lib/ruby/gems/2.4.0/gems/selenium-webdriver-3.3.0/lib/selenium/webdriver/remote/response.rb:69:in `assert_ok'
from ~/.rvm/rubies/ruby-2.4.0/lib/ruby/gems/2.4.0/gems/selenium-webdriver-3.3.0/lib/selenium/webdriver/remote/response.rb:32:in `initialize'
from ~/.rvm/rubies/ruby-2.4.0/lib/ruby/gems/2.4.0/gems/selenium-webdriver-3.3.0/lib/selenium/webdriver/remote/http/common.rb:83:in `new'
from ~/.rvm/rubies/ruby-2.4.0/lib/ruby/gems/2.4.0/gems/selenium-webdriver-3.3.0/lib/selenium/webdriver/remote/http/common.rb:83:in `create_response'
from ~/.rvm/rubies/ruby-2.4.0/lib/ruby/gems/2.4.0/gems/selenium-webdriver-3.3.0/lib/selenium/webdriver/remote/http/default.rb:107:in `request'
from ~/.rvm/rubies/ruby-2.4.0/lib/ruby/gems/2.4.0/gems/selenium-webdriver-3.3.0/lib/selenium/webdriver/remote/http/common.rb:61:in `call'
from ~/.rvm/rubies/ruby-2.4.0/lib/ruby/gems/2.4.0/gems/selenium-webdriver-3.3.0/lib/selenium/webdriver/remote/bridge.rb:669:in `raw_execute'
from ~/.rvm/rubies/ruby-2.4.0/lib/ruby/gems/2.4.0/gems/selenium-webdriver-3.3.0/lib/selenium/webdriver/remote/bridge.rb:647:in `execute'
from ~/.rvm/rubies/ruby-2.4.0/lib/ruby/gems/2.4.0/gems/selenium-webdriver-3.3.0/lib/selenium/webdriver/remote/bridge.rb:120:in `get'
from ~/.rvm/rubies/ruby-2.4.0/lib/ruby/gems/2.4.0/gems/selenium-webdriver-3.3.0/lib/selenium/webdriver/common/navigation.rb:32:in `to'
from (irb):4
from ~/.rvm/rubies/ruby-2.4.0/bin/irb:11:in `<main>'
irb(main):005:0> exit
答案 0 :(得分：0)
最终，我想在我的设置中运行Capybara系统测试（开发机器=运行OS = Linux Ubuntu的VM，通过PuTTY远程访问）。
我找到了让它发挥作用的方法。
为此，我放弃了Chrome及其Selenium驱动程序，用于PhantomJS和恶作剧。
PhantomJS是一个无头浏览器（=无GUI）。它很棒。这是我的步骤（Rails 5.1）：
将宝石'poltergeist'添加到你的Gemfile中，然后注释掉gem'selenium-webdriver'（我们不会使用chrome需要的更晚版本）：
#gem 'selenium-webdriver'
gem 'poltergeist'
运行bundle update
添加poltergeist驱动程序配置（在文件application_system_test_case.rb中），注释掉chrome驱动程序配置：
$ cat test/application_system_test_case.rb
require "test_helper"
require "capybara/poltergeist"
Capybara.javascript_driver = :poltergeist
class ApplicationSystemTestCase < ActionDispatch::SystemTestCase
# driven_by :selenium, using: :chrome, screen_size: [1400, 1400]
driven_by :poltergeist
end
下载'PhamtomJS'无头浏览器，并将其放在PATH中的目录中：
$ wget https://bitbucket.org/ariya/phantomjs/downloads/phantomjs-1.9.8-linux-x86_64.tar.bz2
$ tar -xjvf phantomjs-1.9.8-linux-x86_64.tar.bz2
$ sudo cp phantomjs-1.9.8-linux-x86_64/bin/phantomjs /usr/local/bin
$ sudo chmod +x /usr/local/bin/phantomjs
您已经准备好了，并准备好进行系统测试。例如：
$ rake test TEST=test/system/posts_test.rb
Run options: --seed 38196
# Running:
Puma starting in single mode...
* Version 3.8.2 (ruby 2.4.0-p0), codename: Sassy Salamander
* Min threads: 0, max threads: 1
* Environment: test
* Listening on tcp://0.0.0.0:44265
Use Ctrl-C to stop
You're running an old version of PhantomJS, update to >= 2.1.1 for a better experience.
.
Finished in 1.366478s, 0.7318 runs/s, 0.7318 assertions/s.
1 runs, 1 assertions, 0 failures, 0 errors, 0 skips
$