Modify how poa error redundancy middleware is created for clarity and better cohesion with providing the name of the original poa middleware used.

nucypher/blockchain/eth/clients.py

@@ -16,7 +16,7 @@ from nucypher.blockchain.eth.constants import (
     POA_CHAINS,
     PUBLIC_CHAINS,
 )
-from nucypher.blockchain.middleware.poa import POAErrorRedundancyMiddleware
+from nucypher.blockchain.middleware.poa import create_poa_error_redundancy_middleware
 from nucypher.blockchain.middleware.retry import (
     AlchemyRetryRequestMiddleware,
     InfuraRetryRequestMiddleware,
@@ -113,7 +113,7 @@ class EthereumClient:
 
         # POA error redundancy middleware, just in case
         self.log.debug("Adding POA redundancy middleware")
-        self.add_middleware(POAErrorRedundancyMiddleware)
+        self.add_middleware(create_poa_error_redundancy_middleware(existing_poa_middleware_name=poa_middleware_name))
 
         # simple cache middleware
         self.log.debug("Adding simple_cache_middleware")

nucypher/blockchain/middleware/poa.py

@@ -3,47 +3,43 @@ from typing import Any, Callable
 from web3 import Web3
 from web3.exceptions import ExtraDataLengthError
 from web3.middleware import geth_poa_middleware
-from web3.types import RPCEndpoint, RPCResponse
+from web3.types import Middleware, RPCEndpoint, RPCResponse
 
 from nucypher.utilities.logging import Logger
 
 
-class POAErrorRedundancyMiddleware:
+def create_poa_error_redundancy_middleware(existing_poa_middleware_name: str = "poa") -> Middleware:
     """
     Redundant middleware for replacing already added named poa middleware if ExtraDataLengthError
-    still encountered. Extra layer of defense in case random POA error is observed
+    still encountered. Extra layer of defense in case random POA error is observed.
     """
 
-    POA_MIDDLEWARE_NAME = "poa"
+    def poa_error_redundancy_middleware(
+        make_request: Callable[[RPCEndpoint, Any], RPCResponse], _w3: "Web3"
+    ) -> Callable[[RPCEndpoint, Any], RPCResponse]:
+        logger = Logger("POAErrorRedundancyMiddleware")
 
-    def __init__(
-        self,
-        make_request: Callable[[RPCEndpoint, Any], RPCResponse],
-        w3: Web3,
-        existing_poa_middleware_name: str = POA_MIDDLEWARE_NAME,
-    ):
-        self.w3 = w3
-        self.make_request = make_request
-        self.existing_poa_middleware_name = existing_poa_middleware_name
-        self.logger = Logger(self.__class__.__name__)
+        def middleware(method: RPCEndpoint, params: Any) -> RPCResponse:
+            try:
+                response = make_request(method, params)
+            except ExtraDataLengthError:
+                logger.warn(
+                    "RPC request failed due to extraData error; re-injecting poa middleware and retrying"
+                )
+                # add / replace existing poa middleware; replacement seems unlikely but just in case
+                if _w3.middleware_onion.get(existing_poa_middleware_name):
+                    # we can't have > 1 geth_poa_middleware added (event with different names) so the
+                    # removal-then-add is just for safety.
+                    _w3.middleware_onion.remove(existing_poa_middleware_name)
+                _w3.middleware_onion.inject(
+                    geth_poa_middleware, layer=0, name=existing_poa_middleware_name
+                )
 
-    def __call__(self, method, params) -> RPCResponse:
-        try:
-            response = self.make_request(method, params)
-        except ExtraDataLengthError:
-            self.logger.warn(
-                "RPC request failed due to extraData error; re-injecting poa middleware and retrying"
-            )
-            # add / replace existing poa middleware; replacement seems unlikely but just in case
-            if self.w3.middleware_onion.get(self.existing_poa_middleware_name):
-                # we can't have > 1 geth_poa_middleware added (event with different names) so the
-                # removal-then-add is just for safety.
-                self.w3.middleware_onion.remove(self.existing_poa_middleware_name)
-            self.w3.middleware_onion.inject(
-                geth_poa_middleware, layer=0, name=self.existing_poa_middleware_name
-            )
+                # try again
+                response = make_request(method, params)
 
-            # try again
-            response = self.make_request(method, params)
+            return response
 
-        return response
+        return middleware
+
+    return poa_error_redundancy_middleware