Remove signal testing order dependency (#2382)

* test received signal

* improve error feedback, do not shadow earlier failures

* fix import sorting

---------

Co-authored-by: Marcelo Trylesinski <marcelotryle@gmail.com>

tests/supervisors/test_signal.py

@@ -5,7 +5,7 @@
 import httpx
 import pytest
 
-from tests.utils import run_server
+from tests.utils import assert_signal, run_server
 from uvicorn import Server
 from uvicorn.config import Config
 
@@ -31,8 +31,8 @@ async def wait_app(scope, receive, send):
 
     config = Config(app=wait_app, reload=False, port=unused_tcp_port, timeout_graceful_shutdown=1)
     server: Server
-    async with run_server(config) as server:
-        async with httpx.AsyncClient() as client:
+    with assert_signal(signal.SIGINT):
+        async with run_server(config) as server, httpx.AsyncClient() as client:
             req = asyncio.create_task(client.get(f"http://127.0.0.1:{unused_tcp_port}"))
             await asyncio.sleep(0.1)  # ensure next tick
             server.handle_exit(sig=signal.SIGINT, frame=None)  # exit
@@ -64,8 +64,8 @@ async def forever_app(scope, receive, send):
 
     config = Config(app=forever_app, reload=False, port=unused_tcp_port, timeout_graceful_shutdown=1)
     server: Server
-    async with run_server(config) as server:
-        async with httpx.AsyncClient() as client:
+    with assert_signal(signal.SIGINT):
+        async with run_server(config) as server, httpx.AsyncClient() as client:
             req = asyncio.create_task(client.get(f"http://127.0.0.1:{unused_tcp_port}"))
             await asyncio.sleep(0.1)  # next tick
             # trigger exit, this request should time out in ~1 sec
@@ -94,10 +94,10 @@ async def app(scope, receive, send):
 
     config = Config(app=app, reload=False, port=unused_tcp_port, timeout_graceful_shutdown=1)
     server: Server
-    async with run_server(config) as server:
-        # exit and ensure we do not accept more requests
-        server.handle_exit(sig=signal.SIGINT, frame=None)
-        await asyncio.sleep(0.1)  # next tick
-        async with httpx.AsyncClient() as client:
+    with assert_signal(signal.SIGINT):
+        async with run_server(config) as server, httpx.AsyncClient() as client:
+            # exit and ensure we do not accept more requests
+            server.handle_exit(sig=signal.SIGINT, frame=None)
+            await asyncio.sleep(0.1)  # next tick
             with pytest.raises(httpx.ConnectError):
                 await client.get(f"http://127.0.0.1:{unused_tcp_port}")

tests/utils.py

@@ -2,6 +2,7 @@
 
 import asyncio
 import os
+import signal
 from collections.abc import AsyncIterator
 from contextlib import asynccontextmanager, contextmanager
 from pathlib import Path
@@ -22,6 +23,18 @@ async def run_server(config: Config, sockets: list[socket] | None = None) -> Asy
         task.cancel()
 
 
+@contextmanager
+def assert_signal(sig: signal.Signals):
+    """Check that a signal was received and handled in a block"""
+    seen: set[int] = set()
+    prev_handler = signal.signal(sig, lambda num, frame: seen.add(num))
+    try:
+        yield
+        assert sig in seen, f"process signal {signal.Signals(sig)!r} was not received or handled"
+    finally:
+        signal.signal(sig, prev_handler)
+
+
 @contextmanager
 def as_cwd(path: Path):
     """Changes working directory and returns to previous on exit."""