PYTHON-4672 Clarify Reauthentication and Speculative Authentication combination behavior (#1802)

Co-authored-by: Jib <[email protected]>

Author: blink1073

test/auth_oidc/test_auth_oidc.py

@@ -40,11 +40,7 @@
 from pymongo.errors import AutoReconnect, ConfigurationError, OperationFailure
 from pymongo.hello import HelloCompat
 from pymongo.operations import InsertOne
-from pymongo.synchronous.auth_oidc import (
-    OIDCCallback,
-    OIDCCallbackContext,
-    OIDCCallbackResult,
-)
+from pymongo.synchronous.auth_oidc import OIDCCallback, OIDCCallbackContext, OIDCCallbackResult
 from pymongo.uri_parser import parse_uri
 
 ROOT = Path(__file__).parent.parent.resolve()
@@ -1019,6 +1015,51 @@ def fetch(self, _):
         # Close the client.
         client.close()
 
+    def test_4_4_speculative_authentication_should_be_ignored_on_reauthentication(self):
+        # Create an OIDC configured client that can listen for `SaslStart` commands.
+        listener = EventListener()
+        client = self.create_client(event_listeners=[listener])
+
+        # Preload the *Client Cache* with a valid access token to enforce Speculative Authentication.
+        client2 = self.create_client()
+        client2.test.test.find_one()
+        client.options.pool_options._credentials.cache.data = (
+            client2.options.pool_options._credentials.cache.data
+        )
+        client2.close()
+        self.request_called = 0
+
+        # Perform an `insert` operation that succeeds.
+        client.test.test.insert_one({})
+
+        # Assert that the callback was not called.
+        self.assertEqual(self.request_called, 0)
+
+        # Assert there were no `SaslStart` commands executed.
+        assert not any(
+            event.command_name.lower() == "saslstart" for event in listener.started_events
+        )
+        listener.reset()
+
+        # Set a fail point for `insert` commands of the form:
+        with self.fail_point(
+            {
+                "mode": {"times": 1},
+                "data": {"failCommands": ["insert"], "errorCode": 391},
+            }
+        ):
+            # Perform an `insert` operation that succeeds.
+            client.test.test.insert_one({})
+
+        # Assert that the callback was called once.
+        self.assertEqual(self.request_called, 1)
+
+        # Assert there were `SaslStart` commands executed.
+        assert any(event.command_name.lower() == "saslstart" for event in listener.started_events)
+
+        # Close the client.
+        client.close()
+
     def test_5_1_azure_with_no_username(self):
         if ENVIRON != "azure":
             raise unittest.SkipTest("Test is only supported on Azure")