Reset sse-starlette's cached exit event around every test

sse-starlette below 2.0 (the lowest supported version) keeps a
module-level event on AppStatus that becomes bound to the first event
loop that waits on it, so a test serving an SSE response in process can
inherit an event created on another test's loop and fail. The per-test
reset that test_sse_security.py already carried moves to tests/conftest.py
so the in-process Streamable HTTP tests get it too.

Author: maxisbey

tests/conftest.py

@@ -1,6 +1,27 @@
+from collections.abc import Iterator
+
 import pytest
+from sse_starlette.sse import AppStatus
 
 
 @pytest.fixture
 def anyio_backend():
     return "asyncio"
+
+
+@pytest.fixture(autouse=True)
+def reset_sse_starlette_exit_event() -> Iterator[None]:
+    """sse-starlette<2 caches a module-level anyio.Event on AppStatus. Clear it
+    around each test so it is never bound to a closed event loop: any test that
+    serves an SSE response in process would otherwise inherit the event a
+    previous test created on another loop. Clearing it afterwards matters too,
+    because later test modules fork uvicorn subprocesses on Linux and would
+    otherwise inherit a stale event."""
+
+    def clear() -> None:
+        if hasattr(AppStatus, "should_exit_event"):  # pragma: no cover
+            setattr(AppStatus, "should_exit_event", None)
+
+    clear()
+    yield
+    clear()

tests/server/test_sse_security.py

@@ -4,7 +4,6 @@
 import multiprocessing
 import re
 import socket
-from collections.abc import Iterator
 from typing import Any
 
 import anyio
@@ -29,23 +28,6 @@
 SERVER_NAME = "test_sse_security_server"
 
 
-@pytest.fixture(autouse=True)
-def reset_sse_starlette_exit_event() -> Iterator[None]:
-    """sse-starlette<2 caches a module-level anyio.Event on AppStatus; clear it
-    around each test so it is never bound to a closed event loop. Clearing it
-    afterwards matters too: later test modules fork uvicorn subprocesses on
-    Linux and would otherwise inherit a stale event."""
-    from sse_starlette.sse import AppStatus
-
-    def clear() -> None:
-        if hasattr(AppStatus, "should_exit_event"):  # pragma: no cover
-            setattr(AppStatus, "should_exit_event", None)
-
-    clear()
-    yield
-    clear()
-
-
 @pytest.fixture
 def server_port() -> int:
     with socket.socket() as s: