Fix running tests on python 3.14

See #3664
See #3616

Author: mirthebeijers

pyproject.toml

@@ -120,7 +120,9 @@ filterwarnings = [
   "error",
   "ignore: You seem to already have a custom sys.excepthook handler installed. I'll skip installing Trio's custom handler, but this means MultiErrors will not show full tracebacks.:RuntimeWarning",
   # See: https://github.com/agronholm/anyio/issues/508
-  "ignore: trio.MultiError is deprecated since Trio 0.22.0:trio.TrioDeprecationWarning"
+  "ignore: trio.MultiError is deprecated since Trio 0.22.0:trio.TrioDeprecationWarning",
+  # Python 3.14 deprecates asyncio.iscoroutinefunction, but uvicorn 0.35.0 still uses it
+  "ignore: 'asyncio.iscoroutinefunction' is deprecated:DeprecationWarning"
 ]
 markers = [
   "copied_from(source, changes=None): mark test as copied from somewhere else, along with a description of changes made to accodomate e.g. our test setup",

tests/conftest.py

@@ -235,10 +235,9 @@ def install_signal_handlers(self) -> None:
     async def serve(self, sockets=None):
         self.restart_requested = asyncio.Event()
 
-        loop = asyncio.get_event_loop()
         tasks = {
-            loop.create_task(super().serve(sockets=sockets)),
-            loop.create_task(self.watch_restarts()),
+            asyncio.create_task(super().serve(sockets=sockets)),
+            asyncio.create_task(self.watch_restarts()),
         }
         await asyncio.wait(tasks)
 
@@ -269,7 +268,15 @@ async def watch_restarts(self) -> None:  # pragma: no cover
 
 
 def serve_in_thread(server: TestServer) -> typing.Iterator[TestServer]:
-    thread = threading.Thread(target=server.run)
+    def run_server():
+        # Manually set up event loop for Python 3.14 compatibility
+        loop = asyncio.new_event_loop()
+        asyncio.set_event_loop(loop)
+        server.config.setup_event_loop()
+        loop.run_until_complete(server.serve())
+        loop.close()
+    
+    thread = threading.Thread(target=run_server)
     thread.start()
     try:
         while not server.started:
@@ -282,6 +289,6 @@ def serve_in_thread(server: TestServer) -> typing.Iterator[TestServer]:
 
 @pytest.fixture(scope="session")
 def server() -> typing.Iterator[TestServer]:
-    config = Config(app=app, lifespan="off", loop="asyncio")
+    config = Config(app=app, lifespan="off")
     server = TestServer(config=config)
     yield from serve_in_thread(server)