Format + basic test

src/viser/infra/_infra.py

@@ -11,7 +11,7 @@
 import queue
 import threading
 from asyncio.events import AbstractEventLoop
-from collections.abc import Awaitable, Coroutine
+from collections.abc import Coroutine
 from pathlib import Path
 from typing import Any, Callable, Generator, NewType, TypeVar
 
@@ -22,7 +22,7 @@
 import websockets.exceptions
 from typing_extensions import Literal, assert_never, override
 from websockets import Headers
-from websockets.asyncio.server import Server, ServerConnection
+from websockets.asyncio.server import ServerConnection
 from websockets.http11 import Request, Response
 
 from ._async_message_buffer import AsyncMessageBuffer

tests/test_server_stop.py

@@ -0,0 +1,21 @@
+import socket
+
+import viser
+
+
+def test_server_port_is_freed():
+    server = viser.ViserServer()
+    original_port = server.get_port()
+
+    # Assert that the port is not free.
+    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+    result = sock.connect_ex(("localhost", original_port))
+    assert result == 0
+    sock.close()
+
+    server.stop()
+
+    # Assert that the port is now free.
+    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+    result = sock.connect_ex(("localhost", original_port))
+    assert result != 0