Add shortcut for enabling Firefox' headless mode

Signed-off-by: Alex Rodionov <[email protected]>

Author: franzliedke

rb/lib/selenium/webdriver/firefox/options.rb

@@ -93,6 +93,18 @@ def add_preference(name, value)
           prefs[name] = value
         end
 
+        #
+        # Run Firefox in headless mode.
+        #
+        # @example Enable headless mode
+        #   options = Selenium::WebDriver::Firefox::Options.new
+        #   options.headless!
+        #
+
+        def headless!
+          add_argument '-headless'
+        end
+
         #
         # Sets Firefox profile.
         #

rb/spec/unit/selenium/webdriver/firefox/options_spec.rb

@@ -75,6 +75,13 @@ module Firefox
           end
         end
 
+        describe '#headless!' do
+          it 'adds the -headless command-line flag' do
+            subject.headless!
+            expect(subject.as_json['moz:firefoxOptions'][:args]).to include('-headless')
+          end
+        end
+
         describe '#add_argument' do
           it 'adds a command-line argument' do
             subject.add_argument('foo')