test(chroma0): Add unittests.

Author: Zhe Yu

src/vectorcode/database/chroma0.py

@@ -93,7 +93,7 @@ async def _try_server(base_url: str):
     return False
 
 
-async def _wait_for_server(base_url: str, timeout: int = 10):
+async def _wait_for_server(base_url: str, timeout: int = 10):  # pragma: nocover
     # Poll the server until it's ready or timeout is reached
 
     start_time = asyncio.get_event_loop().time()
@@ -169,7 +169,7 @@ def __new__(cls) -> "_Chroma0ClientManager":
 
         return cls.singleton
 
-    def _atexit(self):
+    def _atexit(self):  # pragma: nocover
         try:
             loop = asyncio.get_running_loop()
         except RuntimeError:
@@ -249,7 +249,7 @@ async def _create_client(self, configs: Config) -> AsyncClientAPI:
             port=int(settings_obj.chroma_server_http_port or 8000),
         )
 
-    def clear(self):
+    def clear(self):  # pragma: nocover
         self.__clients.clear()