Test server init

Author: kennethjyang

src/ephys_link/back_end/server.py

@@ -33,7 +33,7 @@
 from ephys_link.__about__ import __version__
 from ephys_link.back_end.platform_handler import PlatformHandler
 from ephys_link.front_end.console import Console
-from ephys_link.utils.constants import PORT
+from ephys_link.utils.constants import PORT, SERVER_NOT_INITIALIZED_ERROR
 
 # Server message generic types.
 INPUT_TYPE = TypeVar("INPUT_TYPE", bound=VBLBaseModel)
@@ -61,9 +61,8 @@ def __init__(self, options: EphysLinkOptions, platform_handler: PlatformHandler,
         if not self._options.use_proxy:
             # Exit if _sio is not a Server.
             if not isinstance(self._sio, AsyncServer):
-                error = "Server not initialized."
-                self._console.critical_print(error)
-                raise TypeError(error)
+                self._console.critical_print(SERVER_NOT_INITIALIZED_ERROR)
+                raise TypeError(SERVER_NOT_INITIALIZED_ERROR)
 
             self._app = Application()
             self._sio.attach(self._app)  # pyright: ignore [reportUnknownMemberType]

src/ephys_link/utils/constants.py

@@ -58,3 +58,5 @@ def did_not_reach_target_depth_error(request: SetDepthRequest, final_unified_dep
 
 
 EMERGENCY_STOP_MESSAGE = "Emergency Stopping All Manipulators..."
+
+SERVER_NOT_INITIALIZED_ERROR = "Server not initialized."

tests/back_end/test_server.py

@@ -1,11 +1,13 @@
 import pytest
 from pytest_mock import MockerFixture
+from socketio import AsyncServer  # pyright: ignore[reportMissingTypeStubs]
 from vbl_aquarium.models.ephys_link import EphysLinkOptions, GetManipulatorsResponse
 
 import ephys_link.back_end.server
 from ephys_link.back_end.platform_handler import PlatformHandler
 from ephys_link.back_end.server import Server
 from ephys_link.front_end.console import Console
+from ephys_link.utils.constants import SERVER_NOT_INITIALIZED_ERROR
 from tests.conftest import DUMMY_STRING, DUMMY_STRING_LIST
 
 
@@ -30,6 +32,21 @@ def proxy_client(self, platform_handler: PlatformHandler, console: Console) -> S
         """Fixture for server as proxy client."""
         return Server(EphysLinkOptions(use_proxy=True), platform_handler, console)
 
+    def test_failed_server_init(
+        self, platform_handler: PlatformHandler, console: Console, mocker: MockerFixture
+    ) -> None:
+        """Server should raise error if sio is not an AsyncServer."""
+        # Mock out the AsyncServer init.
+        patched_async_server = mocker.patch.object(AsyncServer, "__new__")
+
+        # Act
+        with pytest.raises(TypeError) as init_error:
+            _ = Server(EphysLinkOptions(use_proxy=False), platform_handler, console)
+
+        # Assert
+        patched_async_server.assert_called_once()
+        assert init_error.value.args[0] == SERVER_NOT_INITIALIZED_ERROR
+
     def test_launch_server(
         self, server: Server, platform_handler: PlatformHandler, console: Console, mocker: MockerFixture
     ) -> None: