duplicate browsers to simulate multiple gamers in test envs now handle headless firefox in pipeline correctly

src/functional_tests/test_room_role_select.py

@@ -1,3 +1,5 @@
+import os
+
 from django.conf import settings as django_settings
 from selenium import webdriver
 from selenium.webdriver.common.by import By
@@ -132,7 +134,10 @@ class RoleSelectTest(FunctionalTest):
         )
 
         # Friend's browser
-        self.browser2 = webdriver.Firefox()
+        options2 = webdriver.FirefoxOptions()
+        if os.environ.get("HEADLESS"):
+            options2.add_argument("--headless")
+        self.browser2 = webdriver.Firefox(options=options2)
         try:
             self.browser2.get(self.live_server_url + "/404_no_such_url/")
             from django.conf import settings
@@ -510,7 +515,10 @@ class RoleSelectChannelsTest(ChannelsFunctionalTest):
     def _make_browser2(self, email):
         """Spin up a second Firefox, authenticate email, return the browser."""
         session_key = create_pre_authenticated_session(email)
-        b = webdriver.Firefox()
+        options = webdriver.FirefoxOptions()
+        if os.environ.get("HEADLESS"):
+            options.add_argument("--headless")
+        b = webdriver.Firefox(options=options)
         b.get(self.live_server_url + "/404_no_such_url/")
         b.add_cookie(dict(
             name=django_settings.SESSION_COOKIE_NAME,