ADD: Session.session_id property

Author: nmacholl

CHANGELOG.md

@@ -2,6 +2,9 @@
 
 ## 0.27.0 - TBD
 
+#### Enhancements
+- Added `Session.session_id` property which will contain the numerical session ID once a live session has been authenticated
+
 #### Breaking changes
 - Renamed `DatatbentoLiveProtocol.started` to `DatatbentoLiveProtocol.is_started` which now returns a bool instead of an `asyncio.Event`
 

databento/live/session.py

@@ -227,6 +227,20 @@ def __init__(
 
         self._user_gateway: str | None = user_gateway
         self._port = port
+        self._session_id: int = 0
+
+    @property
+    def session_id(self) -> int:
+        """
+        Return the authenticated session ID. A zero value indicates no session
+        has started.
+
+        Returns
+        -------
+        int
+
+        """
+        return self._session_id
 
     def is_authenticated(self) -> bool:
         """
@@ -489,13 +503,11 @@ async def _connect_task(
                 f"Authentication with {gateway}:{port} timed out after "
                 f"{AUTH_TIMEOUT_SECONDS} second(s).",
             ) from None
-        except ValueError as exc:
-            raise BentoError(f"User authentication failed: {exc!s}") from None
-        else:
-            logger.info("assigned session id %s", session_id)
 
+        self._session_id = session_id
         logger.info(
-            "authentication with remote gateway completed",
+            "authenticated session %s",
+            self.session_id,
         )
 
         return transport, protocol

tests/test_live_client.py

@@ -405,6 +405,29 @@ def test_live_subscribe(
     assert message.start == start
 
 
+@pytest.mark.usefixtures("mock_live_server")
+async def test_live_subscribe_session_id(
+    live_client: client.Live,
+) -> None:
+    """
+    Test that a session ID is assigned after the connection is authenticated.
+    """
+    # Arrange
+    old_session_id = live_client._session.session_id
+
+    # Act
+    live_client.subscribe(
+        dataset=Dataset.GLBX_MDP3,
+        schema=Schema.MBO,
+        stype_in=SType.RAW_SYMBOL,
+        symbols=ALL_SYMBOLS,
+    )
+
+    # Assert
+    assert live_client._session.session_id != old_session_id
+    assert live_client._session.session_id != 0
+
+
 @pytest.mark.skipif(platform.system() == "Windows", reason="timeout on windows")
 async def test_live_subscribe_large_symbol_list(
     live_client: client.Live,