Repository: ethereum/web3.py (python)

Issue:
7.9.0: Can't make batch requests without `provider._is_batching`
### What happened?

in < 7.9.0 you could make both batch and single requests without any fuckery around `_is_batching`

### Code that produced the error

```python
def _raise_stray_errors_from_cache(self) -> None:
        """
        Check the request response cache for any errors not tied to current requests
        and raise them if found.
        """
        if not self._is_batching:
            for (
                response
            ) in self._request_processor._request_response_cache._data.values():
                request = (
                    self._request_processor._request_information_cache.get_cache_entry(
                        generate_cache_key(response["id"])
                    )
                )
                if "error" in response and request is None:
                    # if we find an error response in the cache without a corresponding
                    # request, raise the error
                    validate_rpc_response_and_raise_if_error(
                        response, None, logger=self.logger
                    )
```

### Full error output

```shell
In: web3\providers\persistent\persistent.py
generate_cache_key(response["id"])
                       ~~~~~~~~^^^^^^
TypeError: list indices must be integers or slices, not str
```

### Fill this section in if you know how this could or should be fixed

revert whatever this is

### web3 Version

_No response_

### Python Version

_No response_

### Operating System

_No response_

### Output from `pip freeze`

```shell

```

Pull request:
check _request_information_cache value is a dict before .get-ing from it
### What was wrong?
Mixing batching and non-batching calls causing issues.

Closes #3642 

### How was it fixed?
 - Check that the value from cache is a `dict` before `get`ting from it.
 - Add `try/finally` blocks (via a decorator) to all `make_batch_request` functions to make sure `_is_batching` is `True` when called and reset to `False` afterwards.

### Todo:

- [x] Clean up commit history
- [ ] Add or update documentation related to these changes
- [x] Add entry to the [release notes](https://github.com/ethereum/web3.py/blob/main/newsfragments/README.md)

#### Cute Animal Picture

![image](https://github.com/user-attachments/assets/8c7ab5cf-df2e-4fc0-9007-15efcc2e2b86)


Patch:
diff --git a/newsfragments/3642.bugfix.rst b/newsfragments/3642.bugfix.rst
new file mode 100644
index 00000000..f742e55f
--- /dev/null
+++ b/newsfragments/3642.bugfix.rst
@@ -0,0 +1,1 @@
+Checks that ``PersistentConnectionProvider`` response cache value is a dict before attempting to access it like one. Also adds checks to ``make_batch_request`` to make sure it is in batching mode before being called and is not after.
diff --git a/web3/_utils/batching.py b/web3/_utils/batching.py
index 9155b98c..9c574da0 100644
--- a/web3/_utils/batching.py
+++ b/web3/_utils/batching.py
@@ -1,6 +1,9 @@
 from copy import (
     copy,
 )
+from functools import (
+    wraps,
+)
 from types import (
     TracebackType,
 )
@@ -12,9 +15,11 @@ from typing import (
     Dict,
     Generic,
     List,
+    Protocol,
     Sequence,
     Tuple,
     Type,
+    TypeVar,
     Union,
     cast,
 )
@@ -33,6 +38,7 @@ from web3.exceptions import (
     Web3ValueError,
 )
 from web3.types import (
+    RPCEndpoint,
     TFunc,
     TReturn,
 )
@@ -55,7 +61,6 @@ if TYPE_CHECKING:
         JSONBaseProvider,
     )
     from web3.types import (  # noqa: F401
-        RPCEndpoint,
         RPCResponse,
     )
 
@@ -215,3 +220,39 @@ def sort_batch_response_by_response_ids(
             stacklevel=2,
         )
         return responses
+
+
+class SupportsBatching(Protocol):
+    _is_batching: bool
+
+
+R = TypeVar("R")
+T = TypeVar("T", bound=SupportsBatching)
+
+
+def async_batching_context(
+    method: Callable[[T, List[Tuple[RPCEndpoint, Any]]], Coroutine[Any, Any, R]]
+) -> Callable[[T, List[Tuple[RPCEndpoint, Any]]], Coroutine[Any, Any, R]]:
+    @wraps(method)
+    async def wrapper(self: T, requests: List[Tuple[RPCEndpoint, Any]]) -> R:
+        self._is_batching = True
+        try:
+            return await method(self, requests)
+        finally:
+            self._is_batching = False
+
+    return wrapper
+
+
+def batching_context(
+    method: Callable[[T, List[Tuple[RPCEndpoint, Any]]], R]
+) -> Callable[[T, List[Tuple[RPCEndpoint, Any]]], R]:
+    @wraps(method)
+    def wrapper(self: T, requests: List[Tuple[RPCEndpoint, Any]]) -> R:
+        self._is_batching = True
+        try:
+            return method(self, requests)
+        finally:
+            self._is_batching = False
+
+    return wrapper
diff --git a/web3/providers/ipc.py b/web3/providers/ipc.py
index 3a4f2b8d..23a13384 100644
--- a/web3/providers/ipc.py
+++ b/web3/providers/ipc.py
@@ -30,6 +30,7 @@ from web3.types import (
 )
 
 from .._utils.batching import (
+    batching_context,
     sort_batch_response_by_response_ids,
 )
 from .._utils.caching import (
@@ -201,6 +202,7 @@ class IPCProvider(JSONBaseProvider):
         request = self.encode_rpc_request(method, params)
         return self._make_request(request)
 
+    @batching_context
     def make_batch_request(
         self, requests: List[Tuple[RPCEndpoint, Any]]
     ) -> List[RPCResponse]:
diff --git a/web3/providers/legacy_websocket.py b/web3/providers/legacy_websocket.py
index e2574c8d..1f978e86 100644
--- a/web3/providers/legacy_websocket.py
+++ b/web3/providers/legacy_websocket.py
@@ -27,6 +27,7 @@ from websockets.legacy.client import (
 )
 
 from web3._utils.batching import (
+    batching_context,
     sort_batch_response_by_response_ids,
 )
 from web3._utils.caching import (
@@ -143,6 +144,7 @@ class LegacyWebSocketProvider(JSONBaseProvider):
         )
         return future.result()
 
+    @batching_context
     def make_batch_request(
         self, requests: List[Tuple[RPCEndpoint, Any]]
     ) -> List[RPCResponse]:
diff --git a/web3/providers/persistent/persistent.py b/web3/providers/persistent/persistent.py
index 5d7385bb..4f70af6d 100644
--- a/web3/providers/persistent/persistent.py
+++ b/web3/providers/persistent/persistent.py
@@ -24,6 +24,7 @@ from websockets import (
 
 from web3._utils.batching import (
     BATCH_REQUEST_ID,
+    async_batching_context,
     sort_batch_response_by_response_ids,
 )
 from web3._utils.caching import (
@@ -237,14 +238,17 @@ class PersistentConnectionProvider(AsyncJSONBaseProvider, ABC):
         rpc_request = await self.send_request(method, params)
         return await self.recv_for_request(rpc_request)
 
+    @async_batching_context
     async def make_batch_request(
         self, requests: List[Tuple[RPCEndpoint, Any]]
     ) -> List[RPCResponse]:
         request_data = self.encode_batch_rpc_request(requests)
         await self.socket_send(request_data)
 
+        # breakpoint()
         response = cast(
-            List[RPCResponse], await self._get_response_for_request_id(BATCH_REQUEST_ID)
+            List[RPCResponse],
+            await self._get_response_for_request_id(BATCH_REQUEST_ID),
         )
         return response
 
@@ -320,17 +324,16 @@ class PersistentConnectionProvider(AsyncJSONBaseProvider, ABC):
             for (
                 response
             ) in self._request_processor._request_response_cache._data.values():
-                request = (
-                    self._request_processor._request_information_cache.get_cache_entry(
+                if isinstance(response, dict):
+                    request = self._request_processor._request_information_cache.get_cache_entry(  # noqa: E501
                         generate_cache_key(response["id"])
                     )
-                )
-                if "error" in response and request is None:
-                    # if we find an error response in the cache without a corresponding
-                    # request, raise the error
-                    validate_rpc_response_and_raise_if_error(
-                        response, None, logger=self.logger
-                    )
+                    if "error" in response and request is None:
+                        # if we find an error response in the cache without a
+                        # corresponding request, raise the error
+                        validate_rpc_response_and_raise_if_error(
+                            cast(RPCResponse, response), None, logger=self.logger
+                        )
 
     async def _message_listener(self) -> None:
         self.logger.info(
diff --git a/web3/providers/rpc/async_rpc.py b/web3/providers/rpc/async_rpc.py
index 85e27c33..6e66bae9 100644
--- a/web3/providers/rpc/async_rpc.py
+++ b/web3/providers/rpc/async_rpc.py
@@ -36,6 +36,7 @@ from web3.types import (
 )
 
 from ..._utils.batching import (
+    async_batching_context,
     sort_batch_response_by_response_ids,
 )
 from ..._utils.caching import (
@@ -166,6 +167,7 @@ class AsyncHTTPProvider(AsyncJSONBaseProvider):
         )
         return response
 
+    @async_batching_context
     async def make_batch_request(
         self, batch_requests: List[Tuple[RPCEndpoint, Any]]
     ) -> Union[List[RPCResponse], RPCResponse]:
diff --git a/web3/providers/rpc/rpc.py b/web3/providers/rpc/rpc.py
index 4c41d46e..d60ce8c1 100644
--- a/web3/providers/rpc/rpc.py
+++ b/web3/providers/rpc/rpc.py
@@ -34,6 +34,7 @@ from web3.types import (
 )
 
 from ..._utils.batching import (
+    batching_context,
     sort_batch_response_by_response_ids,
 )
 from ..._utils.caching import (
@@ -174,6 +175,7 @@ class HTTPProvider(JSONBaseProvider):
         )
         return response
 
+    @batching_context
     def make_batch_request(
         self, batch_requests: List[Tuple[RPCEndpoint, Any]]
     ) -> Union[List[RPCResponse], RPCResponse]:


Test patch:
diff --git a/tests/core/providers/test_async_http_provider.py b/tests/core/providers/test_async_http_provider.py
index 4ae96224..21715d9e 100644
--- a/tests/core/providers/test_async_http_provider.py
+++ b/tests/core/providers/test_async_http_provider.py
@@ -130,3 +130,21 @@ async def test_async_http_empty_batch_response(mock_async_post):
 
     # assert that even though there was an error, we have reset the batching state
     assert not async_w3.provider._is_batching
+
+
+@patch(
+    "web3._utils.http_session_manager.HTTPSessionManager.async_make_post_request",
+    new_callable=AsyncMock,
+)
+@pytest.mark.asyncio
+async def test_async_provider_is_batching_when_make_batch_request(mock_post):
+    def assert_is_batching_and_return_response(*_args, **_kwargs) -> bytes:
+        assert provider._is_batching
+        return b'{"jsonrpc":"2.0","id":1,"result":["0x1"]}'
+
+    mock_post.side_effect = assert_is_batching_and_return_response
+    provider = AsyncHTTPProvider()
+
+    assert not provider._is_batching
+    await provider.make_batch_request([("eth_blockNumber", [])])
+    assert not provider._is_batching
diff --git a/tests/core/providers/test_http_provider.py b/tests/core/providers/test_http_provider.py
index 49b1b2ba..c587716a 100644
--- a/tests/core/providers/test_http_provider.py
+++ b/tests/core/providers/test_http_provider.py
@@ -132,3 +132,21 @@ def test_http_empty_batch_response(mock_post):
 
     # assert that even though there was an error, we have reset the batching state
     assert not w3.provider._is_batching
+
+
+@patch(
+    "web3._utils.http_session_manager.HTTPSessionManager.make_post_request",
+    new_callable=Mock,
+)
+def test_sync_provider_is_batching_when_make_batch_request(mock_post):
+    def assert_is_batching_and_return_response(*_args, **_kwargs) -> bytes:
+        assert provider._is_batching
+        return b'{"jsonrpc":"2.0","id":1,"result":["0x1"]}'
+
+    provider = HTTPProvider()
+    assert not provider._is_batching
+
+    mock_post.side_effect = assert_is_batching_and_return_response
+
+    provider.make_batch_request([("eth_blockNumber", [])])
+    assert not provider._is_batching
diff --git a/tests/core/providers/test_ipc_provider.py b/tests/core/providers/test_ipc_provider.py
index 77b62370..7fd8474e 100644
--- a/tests/core/providers/test_ipc_provider.py
+++ b/tests/core/providers/test_ipc_provider.py
@@ -199,3 +199,18 @@ def test_ipc_provider_write_messages_end_with_new_line_delimiter(jsonrpc_ipc_pip
 
     request_data = b'{"jsonrpc": "2.0", "method": "method", "params": [], "id": 0}'
     provider._socket.sock.sendall.assert_called_with(request_data + b"\n")
+
+
+def test_ipc_provider_is_batching_when_make_batch_request(jsonrpc_ipc_pipe_path):
+    def assert_is_batching_and_return_response(*_args, **_kwargs) -> bytes:
+        assert provider._is_batching
+        return [{"id": 0, "jsonrpc": "2.0", "result": {}}]
+
+    provider = IPCProvider(pathlib.Path(jsonrpc_ipc_pipe_path), timeout=3)
+    provider._make_request = Mock()
+    provider._make_request.side_effect = assert_is_batching_and_return_response
+
+    assert not provider._is_batching
+
+    provider.make_batch_request([("eth_blockNumber", [])])
+    assert not provider._is_batching
diff --git a/tests/core/providers/test_websocket_provider.py b/tests/core/providers/test_websocket_provider.py
index 2965addb..10f16d42 100644
--- a/tests/core/providers/test_websocket_provider.py
+++ b/tests/core/providers/test_websocket_provider.py
@@ -534,3 +534,35 @@ async def test_req_info_cache_size_can_be_set_and_warns_when_full(caplog):
             "behavior. Consider increasing the ``request_information_cache_size`` "
             "on the provider."
         ) in caplog.text
+
+
+@pytest.mark.asyncio
+async def test_raise_stray_errors_from_cache_handles_list_response_without_error():
+    provider = WebSocketProvider("ws://mocked")
+    _mock_ws(provider)
+
+    bad_response = [
+        {"id": None, "jsonrpc": "2.0", "error": {"code": 21, "message": "oops"}}
+    ]
+    provider._request_processor._request_response_cache._data["bad_key"] = bad_response
+
+    # assert no errors raised
+    provider._raise_stray_errors_from_cache()
+
+
+@pytest.mark.asyncio
+async def test_websocket_provider_is_batching_when_make_batch_request():
+    def assert_is_batching_and_return_response(*_args, **_kwargs) -> bytes:
+        assert provider._is_batching
+        return b'{"jsonrpc":"2.0","id":1,"result":["0x1"]}'
+
+    provider = WebSocketProvider("ws://mocked")
+    _mock_ws(provider)
+    provider._get_response_for_request_id = AsyncMock()
+    provider._get_response_for_request_id.side_effect = (
+        assert_is_batching_and_return_response
+    )
+
+    assert not provider._is_batching
+    await provider.make_batch_request([("eth_blockNumber", [])])
+    assert not provider._is_batching