fix: return if return route but no response

aries_cloudagent/transport/inbound/http.py

@@ -96,7 +96,12 @@ async def inbound_message_handler(self, request: web.BaseRequest):
                 raise web.HTTPBadRequest()
 
             if inbound.receipt.direct_response_requested:
-                response = await session.wait_response()
+                # Wait for the message to be processed. Only send a response if a response
+                # buffer is present.
+                await inbound.wait_processing_complete()
+                response = (
+                    await session.wait_response() if session.response_buffer else None
+                )
 
                 # no more responses
                 session.can_respond = False

aries_cloudagent/transport/inbound/manager.py

@@ -181,6 +181,8 @@ def dispatch_complete(self, message: InboundMessage, completed: CompletedTask):
         if session and session.accept_undelivered and not session.response_buffered:
             self.process_undelivered(session)
 
+        message.dispatch_processing_complete()
+
     def closed_session(self, session: InboundSession):
         """
         Clean up a closed session.

aries_cloudagent/transport/inbound/message.py

@@ -1,5 +1,6 @@
 """Classes representing inbound messages."""
 
+import asyncio
 from typing import Union
 
 from .receipt import MessageReceipt
@@ -23,3 +24,12 @@ def __init__(
         self.receipt = receipt
         self.session_id = session_id
         self.transport_type = transport_type
+        self.processing_complete_event = asyncio.Event()
+
+    def dispatch_processing_complete(self):
+        """Dispatch processing complete."""
+        self.processing_complete_event.set()
+
+    async def wait_processing_complete(self):
+        """Wait for processing to complete."""
+        await self.processing_complete_event.wait()

aries_cloudagent/transport/inbound/tests/test_http_transport.py

@@ -62,6 +62,7 @@ def receive_message(
         message: InboundMessage,
         can_respond: bool = False,
     ):
+        message.wait_processing_complete = async_mock.CoroutineMock()
         self.message_results.append((message.payload, message.receipt, can_respond))
         if self.result_event:
             self.result_event.set()
@@ -119,13 +120,15 @@ async def test_send_message_outliers(self):
             mock_session.return_value = async_mock.MagicMock(
                 receive=async_mock.CoroutineMock(
                     return_value=async_mock.MagicMock(
-                        receipt=async_mock.MagicMock(direct_response_requested=True)
+                        receipt=async_mock.MagicMock(direct_response_requested=True),
+                        wait_processing_complete=async_mock.CoroutineMock(),
                     )
                 ),
                 can_respond=True,
                 profile=InMemoryProfile.test_profile(),
                 clear_response=async_mock.MagicMock(),
                 wait_response=async_mock.CoroutineMock(return_value=b"Hello world"),
+                response_buffer="something",
             )
             async with self.client.post("/", data=test_message) as resp:
                 result = await resp.text()

aries_cloudagent/transport/inbound/tests/test_message.py

@@ -0,0 +1,30 @@
+import asyncio
+
+from asynctest import TestCase
+
+from ..message import InboundMessage
+from ..receipt import MessageReceipt
+
+
+class TestInboundMessage(TestCase):
+    async def test_wait_response(self):
+        message = InboundMessage(
+            payload="test",
+            connection_id="conn_id",
+            receipt=MessageReceipt(),
+            session_id="session_id",
+        )
+        assert not message.processing_complete_event.is_set()
+        message.dispatch_processing_complete()
+        assert message.processing_complete_event.is_set()
+
+        message = InboundMessage(
+            payload="test",
+            connection_id="conn_id",
+            receipt=MessageReceipt(),
+            session_id="session_id",
+        )
+        assert not message.processing_complete_event.is_set()
+        task = message.wait_processing_complete()
+        message.dispatch_processing_complete()
+        await asyncio.wait_for(task, 1)