Description

In the stop method of Selenium::WebDriver::ServiceManager, I would like to add a check if the process exists before calling the poll_for_exit method of the instance variable @process.

Motivation and Context

The simplest error reproduction is as follows:

$ bundle exec irb
irb(main):001:0> require 'selenium-webdriver'
irb(main):002:0> service = Selenium::WebDriver::Service.chrome
irb(main):003:0> service_manager = Selenium::WebDriver::ServiceManager.new(service)
irb(main):004:0> service_manager.stop
/Users/yoshoku/selenium/rb/lib/selenium/webdriver/common/service_manager.rb:65:in `stop': 
undefined method `poll_for_exit' for nil:NilClass (NoMethodError)
...

I am using selenium-webdriver with capybara and parallel_tests, and sometimes I get this error.

In the stop_server private method of Selenium::WebDriver::ServiceManager, the existence of the process is checked at the beginning. I think that the same check is also necessary before calling the poll_for_exit method.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• I have read the contributing document.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.