Fix exception raise in asgi transport if response is not complete

httpx/_transports/asgi.py

@@ -161,9 +161,15 @@ async def send(message: typing.Dict[str, typing.Any]) -> None:
         try:
             await self.app(scope, receive, send)
         except Exception:  # noqa: PIE-786
-            if self.raise_app_exceptions or not response_complete.is_set():
+            if self.raise_app_exceptions:
                 raise
 
+            response_complete.set()
+            if status_code is None:
+                status_code = 500
+            if response_headers is None:
+                response_headers = {}
+
         assert response_complete.is_set()
         assert status_code is not None
         assert response_headers is not None

tests/test_asgi.py

@@ -3,6 +3,7 @@
 import pytest
 
 import httpx
+from httpx._transports.asgi import ASGITransport
 
 
 async def hello_world(scope, receive, send):
@@ -191,3 +192,12 @@ async def read_body(scope, receive, send):
 
     assert response.status_code == 200
     assert disconnect
+
+
+@pytest.mark.anyio
+async def test_asgi_exc_no_raise():
+    transport = ASGITransport(app=raise_exc, raise_app_exceptions=False)
+    async with httpx.AsyncClient(app=raise_exc, transport=transport) as client:
+        response = await client.get("http://www.example.org/")
+
+        assert response.status_code == 500