refactor: polishes to clarity and consistency

Co-Authored-By: Claude <opus>

Author: pdobacz

src/ethereum/forks/monad_eight/vm/precompiled_contracts/staking.py

@@ -357,7 +357,7 @@ def staking(evm: Evm) -> None:
         evm.output = b"value is nonzero"
         raise RevertInMonadPrecompile
 
-    # Validate calldata size (addValidator does ABI validation instead)
+    # Validate calldata size (addValidator defers to its handler)
     if selector != SELECTOR_ADD_VALIDATOR:
         if len(data) < expected_size:
             evm.output = b"input too short"
@@ -394,5 +394,7 @@ def staking(evm: Evm) -> None:
         elif selector == SELECTOR_WITHDRAW:
             evm.output = b"unknown withdrawal id"
             raise RevertInMonadPrecompile
+        else:
+            raise AssertionError(f"unhandled setter: {selector.hex()}")
     else:
         raise InvalidParameter

src/ethereum/forks/monad_nine/vm/precompiled_contracts/staking.py

@@ -357,7 +357,7 @@ def staking(evm: Evm) -> None:
         evm.output = b"value is nonzero"
         raise RevertInMonadPrecompile
 
-    # Validate calldata size (addValidator does ABI validation instead)
+    # Validate calldata size (addValidator defers to its handler)
     if selector != SELECTOR_ADD_VALIDATOR:
         if len(data) < expected_size:
             evm.output = b"input too short"
@@ -394,5 +394,7 @@ def staking(evm: Evm) -> None:
         elif selector == SELECTOR_WITHDRAW:
             evm.output = b"unknown withdrawal id"
             raise RevertInMonadPrecompile
+        else:
+            raise AssertionError(f"unhandled setter: {selector.hex()}")
     else:
         raise InvalidParameter

tests/monad_eight/staking_precompile/test_fork_transition.py

@@ -18,7 +18,7 @@
 from execution_testing.forks.forks.forks import MONAD_EIGHT
 from execution_testing.forks.helpers import Fork
 
-from .helpers import build_calldata, generous_gas
+from .helpers import CORRECT_SEL_ARGS_OFFSET, build_calldata, generous_gas
 from .spec import (
     GAS_GET_PROPOSER_VAL_ID,
     SELECTOR_GET_PROPOSER_VAL_ID,
@@ -55,7 +55,7 @@ def test_fork_transition(
         + Op.CALL(
             gas=GAS_GET_PROPOSER_VAL_ID + 10000,
             address=STAKING_PRECOMPILE,
-            args_offset=60,
+            args_offset=CORRECT_SEL_ARGS_OFFSET,
             args_size=4,
             ret_offset=0,
             ret_size=32,

tests/monad_eight/staking_precompile/test_precompile_call.py

@@ -34,6 +34,7 @@
 
 from .helpers import (
     CORRECT_SEL_ARGS_OFFSET,
+    CORRECT_SEL_MSTORE_OFFSET,
     WRONG_SEL_ARGS_OFFSET,
     WRONG_SEL_MSTORE_OFFSET,
     build_calldata,
@@ -532,7 +533,7 @@ def test_selector(
         args_size = func.calldata_size
         gas = func.gas_cost + 10000
     else:
-        calldata_setup = Op.MSTORE(32, selector)
+        calldata_setup = Op.MSTORE(CORRECT_SEL_MSTORE_OFFSET, selector)
         args_size = 4
         gas = GAS_UNKNOWN_SELECTOR + 10000