Fix inconsistent return from `sign_transaction`; either a SignedTransaction is returned or HexBytes. Reverting to lowest common denominator which is HexBytes (bytes). This issue was noticed while running the nucypher_dkg script which failed - it uses a keystore signer.

nucypher/blockchain/eth/clients.py

@@ -6,7 +6,6 @@ from typing import Union
 from constant_sorrow.constants import UNKNOWN_DEVELOPMENT_CHAIN_ID
 from cytoolz.dicttoolz import dissoc
 from eth_account import Account
-from eth_account.datastructures import SignedTransaction
 from eth_account.messages import encode_defunct
 from eth_typing.evm import BlockNumber, ChecksumAddress
 from eth_utils import to_canonical_address, to_checksum_address
@@ -558,12 +557,14 @@ class EthereumTesterClient(EthereumClient):
             raise self.UnknownAccount(account)
         return signing_key
 
-    def sign_transaction(self, transaction_dict: dict) -> SignedTransaction:
+    def sign_transaction(self, transaction_dict: dict) -> bytes:
         # Sign using a local private key
         address = to_canonical_address(transaction_dict['from'])
         signing_key = self.__get_signing_key(account=address)
-        signed_transaction = self.w3.eth.account.sign_transaction(transaction_dict, private_key=signing_key)
-        return signed_transaction
+        raw_transaction = self.w3.eth.account.sign_transaction(
+            transaction_dict, private_key=signing_key
+        ).rawTransaction
+        return raw_transaction
 
     def sign_message(self, account: str, message: bytes) -> str:
         """Sign, EIP-191 (Geth) Style"""

nucypher/blockchain/eth/interfaces.py

@@ -617,7 +617,7 @@ class BlockchainInterface:
                 f"({max_cost} @ {max_price_gwei} gwei)",
                 color="yellow",
             )
-        signed_transaction = transacting_power.sign_transaction(transaction_dict)
+        raw_transaction = transacting_power.sign_transaction(transaction_dict)
 
         #
         # Broadcast
@@ -627,9 +627,7 @@ class BlockchainInterface:
             color="yellow",
         )
         try:
-            txhash = self.client.send_raw_transaction(
-                signed_transaction.rawTransaction
-            )  # <--- BROADCAST
+            txhash = self.client.send_raw_transaction(raw_transaction)  # <--- BROADCAST
             emitter.message(f"TXHASH {txhash.hex()}", color="yellow")
         except ValueError:
             raise  # TODO: Unify with Transaction failed handling -- Entry point for _handle_failed_transaction

nucypher/blockchain/eth/signers/base.py

@@ -2,7 +2,6 @@ from abc import ABC, abstractmethod
 from typing import List
 from urllib.parse import urlparse
 
-from eth_account.datastructures import SignedTransaction
 from eth_typing.evm import ChecksumAddress
 from hexbytes.main import HexBytes
 
@@ -78,7 +77,7 @@ class Signer(ABC):
         return NotImplemented
 
     @abstractmethod
-    def sign_transaction(self, transaction_dict: dict) -> SignedTransaction:
+    def sign_transaction(self, transaction_dict: dict) -> bytes:
         return NotImplemented
 
     @abstractmethod

nucypher/blockchain/eth/signers/software.py

@@ -6,7 +6,6 @@ from urllib.parse import urlparse
 
 from cytoolz.dicttoolz import dissoc
 from eth_account.account import Account
-from eth_account.datastructures import SignedTransaction
 from eth_account.messages import encode_defunct
 from eth_account.signers.local import LocalAccount
 from eth_utils.address import is_address, to_canonical_address, to_checksum_address
@@ -99,11 +98,11 @@ class Web3Signer(Signer):
         signature = self.__client.sign_message(account=account, message=message)
         return HexBytes(signature)
 
-    def sign_transaction(self, transaction_dict: dict) -> SignedTransaction:
-        signed_transaction = self.__client.sign_transaction(
+    def sign_transaction(self, transaction_dict: dict) -> bytes:
+        raw_transaction = self.__client.sign_transaction(
             transaction_dict=transaction_dict
         )
-        return signed_transaction
+        return raw_transaction
 
 
 class KeystoreSigner(Signer):
@@ -275,7 +274,7 @@ class KeystoreSigner(Signer):
         return account not in self.__signers
 
     @validate_checksum_address
-    def sign_transaction(self, transaction_dict: dict) -> SignedTransaction:
+    def sign_transaction(self, transaction_dict: dict) -> bytes:
         """
         Produce a raw signed ethereum transaction signed by the account specified
         in the 'from' field of the transaction dictionary.
@@ -355,15 +354,15 @@ class InMemorySigner(Signer):
                 raise self.AccountLocked(account=account)
 
     @validate_checksum_address
-    def sign_transaction(self, transaction_dict: dict) -> SignedTransaction:
+    def sign_transaction(self, transaction_dict: dict) -> bytes:
         sender = transaction_dict["from"]
         signer = self.__get_signer(account=sender)
         if not transaction_dict["to"]:
             transaction_dict = dissoc(transaction_dict, "to")
-        signed_transaction = signer.sign_transaction(
+        raw_transaction = signer.sign_transaction(
             transaction_dict=transaction_dict
         ).rawTransaction
-        return signed_transaction
+        return raw_transaction
 
     @validate_checksum_address
     def sign_message(self, account: str, message: bytes, **kwargs) -> HexBytes:

nucypher/crypto/powers.py

@@ -2,7 +2,6 @@ import inspect
 from typing import List, Optional, Tuple, Union
 
 from eth_account._utils.signing import to_standard_signature_bytes
-from eth_account.datastructures import SignedTransaction
 from eth_typing.evm import ChecksumAddress
 from nucypher_core import (
     EncryptedThresholdDecryptionRequest,
@@ -201,7 +200,7 @@ class TransactingPower(CryptoPowerUp):
         # from the recovery byte, bringing it to the standard choice of {0, 1}.
         return to_standard_signature_bytes(signature)
 
-    def sign_transaction(self, transaction_dict: dict) -> SignedTransaction:
+    def sign_transaction(self, transaction_dict: dict) -> bytes:
         """Signs the transaction with the private key of the TransactingPower."""
         return self._signer.sign_transaction(transaction_dict=transaction_dict)