diff --git a/authentik/core/sources/flow_manager.py b/authentik/core/sources/flow_manager.py
index 399f24933..4e0866f75 100644
--- a/authentik/core/sources/flow_manager.py
+++ b/authentik/core/sources/flow_manager.py
@@ -141,11 +141,11 @@ class SourceFlowManager:
             self._logger.info("denying source because user exists", user=user)
             return Action.DENY, None
         # Should never get here as default enroll case is returned above.
-        return Action.DENY, None
+        return Action.DENY, None  # pragma: no cover
 
     def update_connection(
         self, connection: UserSourceConnection, **kwargs
-    ) -> UserSourceConnection:
+    ) -> UserSourceConnection:  # pragma: no cover
         """Optionally make changes to the connection after it is looked up/created."""
         return connection
 
@@ -178,7 +178,7 @@ class SourceFlowManager:
                 % {"source": self.source.name}
             ),
         )
-        return redirect("/")
+        return redirect(reverse("authentik_core:root-redirect"))
 
     # pylint: disable=unused-argument
     def get_stages_to_append(self, flow: Flow) -> list[Stage]:
diff --git a/authentik/core/tests/test_source_flow_manager.py b/authentik/core/tests/test_source_flow_manager.py
new file mode 100644
index 000000000..a869b403b
--- /dev/null
+++ b/authentik/core/tests/test_source_flow_manager.py
@@ -0,0 +1,160 @@
+"""Test Source flow_manager"""
+from django.contrib.auth.models import AnonymousUser
+from django.contrib.messages.middleware import MessageMiddleware
+from django.contrib.sessions.middleware import SessionMiddleware
+from django.http.request import HttpRequest
+from django.test import TestCase
+from django.test.client import RequestFactory
+from guardian.utils import get_anonymous_user
+
+from authentik.core.models import SourceUserMatchingModes, User
+from authentik.core.sources.flow_manager import Action
+from authentik.flows.tests.test_planner import dummy_get_response
+from authentik.providers.oauth2.generators import generate_client_id
+from authentik.sources.oauth.models import OAuthSource, UserOAuthSourceConnection
+from authentik.sources.oauth.views.callback import OAuthSourceFlowManager
+
+
+class TestSourceFlowManager(TestCase):
+    """Test Source flow_manager"""
+
+    def setUp(self) -> None:
+        super().setUp()
+        self.source = OAuthSource.objects.create(name="test")
+        self.factory = RequestFactory()
+        self.identifier = generate_client_id()
+
+    def get_request(self, user: User) -> HttpRequest:
+        """Helper to create a get request with session and message middleware"""
+        request = self.factory.get("/")
+        request.user = user
+        middleware = SessionMiddleware(dummy_get_response)
+        middleware.process_request(request)
+        request.session.save()
+        middleware = MessageMiddleware(dummy_get_response)
+        middleware.process_request(request)
+        request.session.save()
+        return request
+
+    def test_unauthenticated_enroll(self):
+        """Test un-authenticated user enrolling"""
+        flow_manager = OAuthSourceFlowManager(
+            self.source, self.get_request(AnonymousUser()), self.identifier, {}
+        )
+        action, _ = flow_manager.get_action()
+        self.assertEqual(action, Action.ENROLL)
+        flow_manager.get_flow()
+
+    def test_unauthenticated_auth(self):
+        """Test un-authenticated user authenticating"""
+        UserOAuthSourceConnection.objects.create(
+            user=get_anonymous_user(), source=self.source, identifier=self.identifier
+        )
+
+        flow_manager = OAuthSourceFlowManager(
+            self.source, self.get_request(AnonymousUser()), self.identifier, {}
+        )
+        action, _ = flow_manager.get_action()
+        self.assertEqual(action, Action.AUTH)
+        flow_manager.get_flow()
+
+    def test_authenticated_link(self):
+        """Test authenticated user linking"""
+        UserOAuthSourceConnection.objects.create(
+            user=get_anonymous_user(), source=self.source, identifier=self.identifier
+        )
+        user = User.objects.create(username="foo", email="foo@bar.baz")
+        flow_manager = OAuthSourceFlowManager(
+            self.source, self.get_request(user), self.identifier, {}
+        )
+        action, _ = flow_manager.get_action()
+        self.assertEqual(action, Action.LINK)
+        flow_manager.get_flow()
+
+    def test_unauthenticated_enroll_email(self):
+        """Test un-authenticated user enrolling (link on email)"""
+        User.objects.create(username="foo", email="foo@bar.baz")
+        self.source.user_matching_mode = SourceUserMatchingModes.EMAIL_LINK
+
+        # Without email, deny
+        flow_manager = OAuthSourceFlowManager(
+            self.source, self.get_request(AnonymousUser()), self.identifier, {}
+        )
+        action, _ = flow_manager.get_action()
+        self.assertEqual(action, Action.DENY)
+        flow_manager.get_flow()
+        # With email
+        flow_manager = OAuthSourceFlowManager(
+            self.source,
+            self.get_request(AnonymousUser()),
+            self.identifier,
+            {"email": "foo@bar.baz"},
+        )
+        action, _ = flow_manager.get_action()
+        self.assertEqual(action, Action.LINK)
+        flow_manager.get_flow()
+
+    def test_unauthenticated_enroll_username(self):
+        """Test un-authenticated user enrolling (link on username)"""
+        User.objects.create(username="foo", email="foo@bar.baz")
+        self.source.user_matching_mode = SourceUserMatchingModes.USERNAME_LINK
+
+        # Without username, deny
+        flow_manager = OAuthSourceFlowManager(
+            self.source, self.get_request(AnonymousUser()), self.identifier, {}
+        )
+        action, _ = flow_manager.get_action()
+        self.assertEqual(action, Action.DENY)
+        flow_manager.get_flow()
+        # With username
+        flow_manager = OAuthSourceFlowManager(
+            self.source,
+            self.get_request(AnonymousUser()),
+            self.identifier,
+            {"username": "foo"},
+        )
+        action, _ = flow_manager.get_action()
+        self.assertEqual(action, Action.LINK)
+        flow_manager.get_flow()
+
+    def test_unauthenticated_enroll_username_deny(self):
+        """Test un-authenticated user enrolling (deny on username)"""
+        User.objects.create(username="foo", email="foo@bar.baz")
+        self.source.user_matching_mode = SourceUserMatchingModes.USERNAME_DENY
+
+        # With non-existent username, enroll
+        flow_manager = OAuthSourceFlowManager(
+            self.source,
+            self.get_request(AnonymousUser()),
+            self.identifier,
+            {
+                "username": "bar",
+            },
+        )
+        action, _ = flow_manager.get_action()
+        self.assertEqual(action, Action.ENROLL)
+        flow_manager.get_flow()
+        # With username
+        flow_manager = OAuthSourceFlowManager(
+            self.source,
+            self.get_request(AnonymousUser()),
+            self.identifier,
+            {"username": "foo"},
+        )
+        action, _ = flow_manager.get_action()
+        self.assertEqual(action, Action.DENY)
+        flow_manager.get_flow()
+
+    def test_unauthenticated_enroll_link_non_existent(self):
+        """Test un-authenticated user enrolling (link on username), username doesn't exist"""
+        self.source.user_matching_mode = SourceUserMatchingModes.USERNAME_LINK
+
+        flow_manager = OAuthSourceFlowManager(
+            self.source,
+            self.get_request(AnonymousUser()),
+            self.identifier,
+            {"username": "foo"},
+        )
+        action, _ = flow_manager.get_action()
+        self.assertEqual(action, Action.ENROLL)
+        flow_manager.get_flow()