Add mix_hash to the BLOCK_RESULTS_KEY_MAPPING from eth-tester

Author: kclowes

tests/core/middleware/test_eth_tester_middleware.py

@@ -31,10 +31,7 @@ def test_get_block_formatters(w3):
     all_block_keys = set(BlockData.__annotations__.keys())
     latest_block_keys = set(latest_block.keys())
 
-    keys_diff = all_block_keys.difference(latest_block_keys)
-    assert len(keys_diff) == 2
-    # mixHash and miner not implemented in eth-tester
-    assert keys_diff == set(["mixHash", "miner"])
+    assert all_block_keys == latest_block_keys
 
 
 @pytest.mark.parametrize(

web3/providers/eth_tester/middleware.py

@@ -186,6 +186,7 @@ def is_hexstr(value: Any) -> bool:
     "extra_data": "extraData",
     "gas_used": "gasUsed",
     "base_fee_per_gas": "baseFeePerGas",
+    "mix_hash": "mixHash",
     # eth-tester changed the miner key to coinbase since
     # there is no longer any mining happening, but the current
     # JSON-RPC spec still says miner