WebMock stopping selenium from deleting session

Question

System

• Ruby v2.6
• WebMock gem v3.18.1
• Selenium Webdriver gem v4.1.0
• RSpec gem v3.11.0
• Capybara gem v3.36.0

Summary

Whilst successfully running a suite of tests on GitLab CI[1], WebMock intercepts a request from Capybara's Selenium driver to delete a session[2].

743 examples, 0 failures, 30 pending

/builds/abelsoninfo/aws/pips/pips-console/vendor/ruby/ruby/2.6.0/gems/webmock-3.18.1/lib/webmock/http_lib_adapters/net_http.rb:104:in `request': Real HTTP connections are disabled. Unregistered request: DELETE http://selenium__standalone-chrome:4444/wd/hub/session/0146cfc5158d585f445cfcdbda289733

Although the error appears after the tests have run I wonder if it occurs whilst the specs are running? This is due to seeing newlines appearing in the RSpec output:

...................................................................................................................................................................................................................................................................... ............................................................................................................................................................................................................................... .....................................................................................................................................................................................**...**............................................******

In spec/support/capybara.rb I have allowed connections to any URL with selenium, or session in it:

selenium_session_requests = %r{/((__.+__)|(hub/session.*))$}
allowed_connections = [
  '0.0.0.0', '127.0.0.1', 'https://chromedriver.storage.googleapis.com',
  'localhost', /selenium/, selenium_session_requests
].freeze

RSpec.configure do |config|
  config.before(:suite) do
    WebMock.enable!
  end

  config.after(:suite) do
    WebMock.disable!
  end

  Capybara.app_host = "http://#{Capybara.server_host}:#{Capybara.server_port}"

  Capybara.javascript_driver = ENV.fetch('CAPYBARA_JAVASCRIPT_DRIVER', :chrome_headless).to_sym

  WebMock.disable_net_connect!(allow: allowed_connections, net_http_connect_on_start: allowed_connections)
end

I have previously confirmed in the before(:suite) block that a session URL, such as http://selenium__standalone-chrome:4444/wd/hub/session/0146cfc5158d585f445cfcdbda289733 would be allowed by WebMock.

Per the suggestion in [2] I stubbed the request - though I don't believe this is desired behaviour - but that still caused the same error.

Observed behaviour

WebMock does not allow the Selenium driver to exit the browser.

Desired behaviour

The browser is closed, and no errors are raised.

[1] In .gitlab-ci.yml I have a docker service to enable the use of Selenium:

image: ruby:2.6
  services:
    - postgres:10.1
    - selenium/standalone-chrome:latest
    - redis:latest

The URL for that service is exposed to my specs via an environment variable:

- export SELENIUM_REMOTE_URL="http://selenium__standalone-chrome:4444/wd/hub"

[2] Here is the full output from the WebMock error:

/builds/abelsoninfo/aws/pips/pips-console/vendor/ruby/ruby/2.6.0/gems/webmock-3.18.1/lib/webmock/http_lib_adapters/net_http.rb:104:in request': Real HTTP connections are disabled. Unregistered request: DELETE http://selenium__standalone-chrome:4444/wd/hub/session/0146cfc5158d585f445cfcdbda289733 with headers {'Accept'=>'application/json', 'Accept-Encoding'=>'gzip;q=1.0,deflate;q=0.6,identity;q=0.3', 'Content-Type'=>'application/json; charset=UTF-8', 'User-Agent'=>'selenium/4.1.0 (ruby linux)'} (WebMock::NetConnectNotAllowedError) You can stub this request with the following snippet: stub_request(:delete, "http://selenium__standalone-chrome:4444/wd/hub/session/0146cfc5158d585f445cfcdbda289733"). with( headers: { 'Accept'=>'application/json', 'Accept-Encoding'=>'gzip;q=1.0,deflate;q=0.6,identity;q=0.3', 'Content-Type'=>'application/json; charset=UTF-8', 'User-Agent'=>'selenium/4.1.0 (ruby linux)' }). to_return(status: 200, body: "", headers: {}) ============================================================ from /builds/abelsoninfo/aws/pips/pips-console/vendor/ruby/ruby/2.6.0/gems/selenium-webdriver-4.1.0/lib/selenium/webdriver/remote/http/default.rb:124:in response_for' from /builds/abelsoninfo/aws/pips/pips-console/vendor/ruby/ruby/2.6.0/gems/selenium-webdriver-4.1.0/lib/selenium/webdriver/remote/http/default.rb:77:in request' from /builds/abelsoninfo/aws/pips/pips-console/vendor/ruby/ruby/2.6.0/gems/selenium-webdriver-4.1.0/lib/selenium/webdriver/remote/http/common.rb:59:in call' from /builds/abelsoninfo/aws/pips/pips-console/vendor/ruby/ruby/2.6.0/gems/selenium-webdriver-4.1.0/lib/selenium/webdriver/remote/bridge.rb:588:in execute' from /builds/abelsoninfo/aws/pips/pips-console/vendor/ruby/ruby/2.6.0/gems/selenium-webdriver-4.1.0/lib/selenium/webdriver/remote/bridge.rb:188:in quit' from /builds/abelsoninfo/aws/pips/pips-console/vendor/ruby/ruby/2.6.0/gems/selenium-webdriver-4.1.0/lib/selenium/webdriver/common/driver.rb:181:in quit' from /builds/abelsoninfo/aws/pips/pips-console/vendor/ruby/ruby/2.6.0/gems/capybara-3.36.0/lib/capybara/selenium/driver.rb:293:in quit' from /builds/abelsoninfo/aws/pips/pips-console/vendor/ruby/ruby/2.6.0/gems/capybara-3.36.0/lib/capybara/selenium/driver.rb:512:in `block in setup_exit_handler'