fix: allow passing extra options to Selenium::WebDriver

Some environments like Docker require special options (-headless for
example) which is impossible to specify in the current setup. Add an
ommitable `opts` parameter for it.

packages/axe-core-selenium/README.md

@@ -20,23 +20,34 @@ require 'axe-selenium'
 # configure `AxeSelenium`
 
 driver = AxeSelenium.configure(:firefox) do |c|
-  # see below for a full list of configuration 
+  # see below for a full list of configuration
   c.jslib_path = "next-version/axe.js"
 end
 
 # use the driver configuration instance
 driver.page.navigate.to 'https://www.deque.com/'
 ```
 
-### API 
+Custom options can be passed to the underlying driver:
+
+```rb
+require 'axe-selenium'
+
+options = Selenium::WebDriver::Options.firefox
+options.args << '-headless'
+
+driver = AxeSelenium.configure(:firefox, options) {}
+```
+
+### API
 
 #### `AxeSelenium.configure`
 
 The configure method takes 1 optional argument as a [symbol][] and a configuration block object: `configure(*arg, &block)`
 
 The optional argument is a browser name for `selenium-webdriver`. The valid browser names are:
 - `:firefox` (default)
-- `:chrome` 
+- `:chrome`
 - `:safari`
 
 > Note: Please ensure respective drivers (eg: [`geckodriver`][]) are installed in your machine.
@@ -67,4 +78,4 @@ bundle exec rspec
 [axe API]: https://github.com/dequelabs/axe-core/blob/develop/doc/API.md
 [Selenium Webdriver]: https://rubygems.org/gems/selenium-webdriver
 [`geckodriver`]: https://github.com/mozilla/geckodriver/releases
-[symbol]: https://ruby-doc.org/core-2.5.0/Symbol.html
+[symbol]: https://ruby-doc.org/core-2.5.0/Symbol.html

packages/axe-core-selenium/lib/axe-selenium.rb

@@ -4,8 +4,9 @@
 module AxeSelenium
   # configure method
   # - which takes an optional argument browser
+  # - an optional options (sic) object to configure the underlying driver
   # - and a configuration block optional for Axe
-  def self.configure(browser = :firefox)
+  def self.configure(browser = :firefox, opts = {})
     # instantiate axe configuration (singleton) with defaults or given config
     if !block_given?
       raise Exception.new "Please provide a configure block for AxeSelenium"
@@ -14,7 +15,7 @@ def self.configure(browser = :firefox)
     config = Axe::Configuration.instance
 
     # provide a selenium webdriver page object
-    config.page = get_driver(browser)
+    config.page = get_driver(browser, opts)
 
     # await and return
     yield config
@@ -23,7 +24,7 @@ def self.configure(browser = :firefox)
 
   private
 
-  def self.get_driver(browserSymbol)
-    Selenium::WebDriver.for browserSymbol
+  def self.get_driver(browserSymbol, opts)
+    Selenium::WebDriver.for browserSymbol, options: opts
   end
 end