Allows None to be set for the sameSite attribute (#9771)

* Allows None to be set for the sameSite attribute

* Fixes formatting

Co-authored-by: David Burns <david.burns@theautomatedtester.co.uk>

Author: gpt14

py/selenium/webdriver/remote/webdriver.py

@@ -1117,7 +1117,7 @@ def add_cookie(self, cookie_dict) -> None:
 
         """
         if 'sameSite' in cookie_dict:
-            assert cookie_dict['sameSite'] in ['Strict', 'Lax']
+            assert cookie_dict['sameSite'] in ['Strict', 'Lax', 'None']
             self.execute(Command.ADD_COOKIE, {'cookie': cookie_dict})
         else:
             self.execute(Command.ADD_COOKIE, {'cookie': cookie_dict})

py/test/selenium/webdriver/common/cookie_tests.py

@@ -57,6 +57,18 @@ def same_site_cookie_lax(webserver):
     return same_site_cookie_lax
 
 
+@pytest.fixture
+def same_site_cookie_none(webserver):
+    same_site_cookie_none = {
+        'name': 'foo',
+        'value': 'bar',
+        'path': '/',
+        'domain': webserver.host,
+        'sameSite': 'None',
+        'secure': True}
+    return same_site_cookie_none
+
+
 @pytest.fixture(autouse=True)
 def pages(request, driver, pages):
     pages.load('simpleTest.html')
@@ -88,6 +100,15 @@ def testAddCookieSameSiteLax(same_site_cookie_lax, driver):
     assert 'sameSite' in returned and returned['sameSite'] == 'Lax'
 
 
+@pytest.mark.xfail_firefox(reason='sameSite cookie attribute not implemented')
+@pytest.mark.xfail_remote(reason='sameSite cookie attribute not implemented')
+@pytest.mark.xfail_safari
+def testAddCookieSameSiteNone(same_site_cookie_none, driver):
+    driver.add_cookie(same_site_cookie_none)
+    # Note that insecure sites (http:) can't set cookies with the Secure directive.
+    # driver.get_cookie would return None
+
+
 @pytest.mark.xfail_ie
 @pytest.mark.xfail_safari
 def testAddingACookieThatExpiredInThePast(cookie, driver):