Keep the message listener alive inside a while True

tests/core/providers/test_wsv2_provider.py

@@ -3,6 +3,7 @@
 import pytest
 from unittest.mock import (
     AsyncMock,
+    Mock,
     patch,
 )
 
@@ -139,14 +140,20 @@ async def test_msg_listener_task_silences_exceptions_by_default_and_error_logs(c
     provider._ws = WebsocketMessageStreamMock(
         raise_exception=Exception("test exception")
     )
-    await provider._message_listener_task
+    await asyncio.sleep(0.05)
 
     assert "test exception" in caplog.text
     assert (
         "Exception caught in listener, error logging and keeping listener background "
         "task alive.\n    error=test exception"
     ) in caplog.text
 
+    # assert is still running
+    assert not provider._message_listener_task.cancelled()
+
+    # proper cleanup
+    await provider.disconnect()
+
 
 @pytest.mark.asyncio
 async def test_msg_listener_task_raises_when_raise_listener_task_exceptions_is_true():
@@ -169,17 +176,12 @@ async def test_msg_listener_task_raises_when_raise_listener_task_exceptions_is_t
 
 
 @pytest.mark.asyncio
-@skip_if_py37
 async def test_listen_event_awaits_msg_processing_when_subscription_queue_is_full():
     """
     This test is to ensure that the `listen_event` method will wait for the
     `process_subscriptions` method to process a message when the subscription queue
     is full.
     """
-    from unittest.mock import (
-        AsyncMock,
-    )
-
     with patch(
         "web3.providers.websocket.websocket_v2.connect", new=lambda *_1, **_2: _coro()
     ):
@@ -204,7 +206,7 @@ async def test_listen_event_awaits_msg_processing_when_subscription_queue_is_ful
 
     # mock listen event
     async_w3.provider._listen_event.wait = AsyncMock()
-    async_w3.provider._listen_event.set = AsyncMock()
+    async_w3.provider._listen_event.set = Mock()
 
     # mock subscription and add to active subscriptions
     sub_id = "0x1"
@@ -252,3 +254,6 @@ async def test_listen_event_awaits_msg_processing_when_subscription_queue_is_ful
 
     # assert we set the _listen_event after we consume the message
     async_w3.provider._listen_event.set.assert_called_once()
+
+    # proper cleanup
+    await async_w3.provider.disconnect()

web3/providers/websocket/websocket_v2.py

@@ -216,23 +216,26 @@ async def _ws_message_listener(self) -> None:
             "Websocket listener background task started. Storing all messages in "
             "appropriate request processor queues / caches to be processed."
         )
-        try:
-            async for raw_message in self._ws:
-                # sleep(0) here seems to be the most efficient way to yield control
-                # back to the event loop to share the loop with other tasks.
-                await asyncio.sleep(0)
+        while True:
+            # the use of sleep(0) seems to be the most efficient way to yield control
+            # back to the event loop to share the loop with other tasks.
+            await asyncio.sleep(0)
 
-                response = json.loads(raw_message)
-                subscription = response.get("method") == "eth_subscription"
-                await self._request_processor.cache_raw_response(
-                    response, subscription=subscription
+            try:
+                async for raw_message in self._ws:
+                    await asyncio.sleep(0)
+
+                    response = json.loads(raw_message)
+                    subscription = response.get("method") == "eth_subscription"
+                    await self._request_processor.cache_raw_response(
+                        response, subscription=subscription
+                    )
+            except Exception as e:
+                if self.raise_listener_task_exceptions:
+                    # If ``True``, raise; else, error log & keep task alive
+                    raise e
+
+                self.logger.error(
+                    "Exception caught in listener, error logging and keeping listener "
+                    f"background task alive.\n    error={e}"
                 )
-        except Exception as e:
-            if self.raise_listener_task_exceptions:
-                # If ``True``, raise; else, error log & keep task alive
-                raise e
-
-            self.logger.error(
-                "Exception caught in listener, error logging and keeping listener "
-                f"background task alive.\n    error={e}"
-            )