Use HexBytes.hex() for sign-and-send-raw middlewares

- Don't assume some conversion is going to happen later down the line. The JSON-RPC asks for hexstr value, give it the hexstr value if we can guarantee that it is a hexstr. We already have the type as HexBytes so call ``.hex()`` on the value and send that as the param.
- closes #2936

Author: fselmo

tests/core/middleware/test_transaction_signing.py

@@ -12,6 +12,7 @@
 )
 from eth_utils import (
     ValidationError as EthUtilsValidationError,
+    is_hexstr,
     to_bytes,
     to_hex,
 )
@@ -310,7 +311,7 @@ def assert_method_and_txn_signed(actual, expected):
     raw_txn = actual[1][0]
     actual_method = actual[0]
     assert actual_method == expected
-    assert isinstance(raw_txn, bytes)
+    assert is_hexstr(raw_txn)
 
 
 @pytest.fixture()
@@ -417,7 +418,7 @@ def test_sign_and_send_raw_middleware_with_byte_addresses(
     raw_txn = actual[1][0]
     actual_method = actual[0]
     assert actual_method == "eth_sendRawTransaction"
-    assert isinstance(raw_txn, bytes)
+    assert is_hexstr(raw_txn)
 
 
 # -- async -- #
@@ -613,4 +614,4 @@ async def test_async_sign_and_send_raw_middleware_with_byte_addresses(
     raw_txn = actual[1][0]
     actual_method = actual[0]
     assert actual_method == "eth_sendRawTransaction"
-    assert isinstance(raw_txn, bytes)
+    assert is_hexstr(raw_txn)

web3/middleware/signing.py

@@ -178,7 +178,7 @@ def middleware(method: RPCEndpoint, params: Any) -> RPCResponse:
             account = accounts[transaction["from"]]
             raw_tx = account.sign_transaction(transaction).rawTransaction
 
-            return make_request(RPCEndpoint("eth_sendRawTransaction"), [raw_tx])
+            return make_request(RPCEndpoint("eth_sendRawTransaction"), [raw_tx.hex()])
 
         return middleware
 
@@ -229,7 +229,10 @@ async def middleware(method: RPCEndpoint, params: Any) -> RPCResponse:
             account = accounts[to_checksum_address(tx_from)]
             raw_tx = account.sign_transaction(filled_transaction).rawTransaction
 
-            return await make_request(RPCEndpoint("eth_sendRawTransaction"), [raw_tx])
+            return await make_request(
+                RPCEndpoint("eth_sendRawTransaction"),
+                [raw_tx.hex()],
+            )
 
         return middleware