feat(tests,fw): Add MIP-8 implementation and tests

packages/testing/src/execution_testing/__init__.py

@@ -106,6 +106,7 @@
     gas_test,
     generate_system_contract_deploy_test,
     generate_system_contract_error_test,
+    oog_test,
 )
 from .vm import (
     Bytecode,
@@ -226,4 +227,5 @@
     "generate_system_contract_deploy_test",
     "generate_system_contract_error_test",
     "keccak256",
+    "oog_test",
 )

packages/testing/src/execution_testing/fixtures/pre_alloc_groups.py

@@ -55,7 +55,7 @@ def calculate_genesis(self) -> FixtureHeader:
         return FixtureHeader.genesis(
             self.fork.transitions_from(),
             self.environment,
-            self.pre.state_root(),
+            self.pre.state_root(self.fork),
         )
 
     def add_test_alloc(self, test_id: str, new_pre: Alloc) -> None:
@@ -272,11 +272,11 @@ class GroupPreAlloc(Alloc):
     _cached_state_root: Hash | None = PrivateAttr(None)
     _model_dump_cache: ModelDumpCache | None = PrivateAttr(None)
 
-    def state_root(self) -> Hash:
+    def state_root(self, fork: Any = None) -> Hash:
         """On pre-alloc groups, which are normally very big, always cache."""
         if self._cached_state_root is not None:
             return self._cached_state_root
-        return super().state_root()
+        return super().state_root(fork)
 
     def model_dump(  # type: ignore[override]
         self, mode: Literal["json", "python"], **kwargs: Any

packages/testing/src/execution_testing/forks/__init__.py

@@ -8,6 +8,7 @@
     BPO4,
     BPO5,
     MONAD_EIGHT,
+    MONAD_NEXT,
     MONAD_NINE,
     Amsterdam,
     ArrowGlacier,
@@ -37,6 +38,7 @@
     BPO3ToBPO4AtTime15k,
     CancunToPragueAtTime15k,
     MONAD_EIGHTToMONAD_NINEAtTime15k,
+    MONAD_NINEToMONAD_NEXTAtTime15k,
     OsakaToBPO1AtTime15k,
     ParisToShanghaiAtTime15k,
     PragueToMONAD_EIGHTAtTime15k,
@@ -124,6 +126,8 @@
     "MONAD_EIGHT",
     "MONAD_EIGHTToMONAD_NINEAtTime15k",
     "MONAD_NINE",
+    "MONAD_NINEToMONAD_NEXTAtTime15k",
+    "MONAD_NEXT",
     "BPO1",
     "BPO1ToBPO2AtTime15k",
     "BPO2",

packages/testing/src/execution_testing/forks/forks/forks.py

@@ -1666,6 +1666,94 @@ def c(w: int) -> int:
         return fn
 
 
+class MONAD_NEXT(MONAD_NINE, solc_name="cancun"):  # noqa: N801
+    """MONAD_NEXT fork."""
+
+    @classmethod
+    def gas_costs(cls) -> GasCosts:
+        """Return gas costs with MIP-8 page-based storage constants."""
+        return replace(
+            MONAD_NINE.gas_costs(),
+            PAGE_BASE_COST=100,
+            PAGE_LOAD_COST=8_000,
+            PAGE_WRITE_COST=2_800,
+            PAGE_STATE_GROWTH_COST=17_000,
+        )
+
+    @classmethod
+    def opcode_gas_map(
+        cls,
+    ) -> Dict[OpcodeBase, int | Callable[[OpcodeBase], int]]:
+        """Override SLOAD/SSTORE gas with MIP-8 page-level rules."""
+        base_map = super().opcode_gas_map()
+        gas_costs = cls.gas_costs()
+        return {
+            **base_map,
+            Opcodes.SLOAD: lambda op: (
+                gas_costs.PAGE_BASE_COST
+                if op.metadata["page_load_warm"] or op.metadata["key_warm"]
+                else gas_costs.PAGE_LOAD_COST + gas_costs.PAGE_BASE_COST
+            ),
+            Opcodes.SSTORE: lambda op: cls._calculate_sstore_gas_mip8(
+                op, gas_costs
+            ),
+        }
+
+    @classmethod
+    def opcode_refund_map(
+        cls,
+    ) -> Dict[OpcodeBase, int | Callable[[OpcodeBase], int]]:
+        """MIP-8 removes SSTORE refunds."""
+        return {}
+
+    @classmethod
+    def _calculate_sstore_gas_mip8(
+        cls, opcode: OpcodeBase, gas_costs: GasCosts
+    ) -> int:
+        """
+        Calculate SSTORE gas cost per MIP-8.
+
+        Metadata fields used:
+        - current_value: value right before this SSTORE (v_original
+          in spec terms — `None` falls back to original_value)
+        - new_value: value being written
+        - page_load_warm: page already in read_accessed_pages
+        - page_write_warm: page already in write_accessed_pages
+        - key_warm: any prior SLOAD/SSTORE on this key — implies
+          page_load_warm, but for prior SSTORE will still misprice
+        - current_state_growth: per-page counter before this op
+        - net_state_growth: per-page peak before this op
+        """
+        metadata = opcode.metadata
+
+        v_original = metadata["current_value"]
+        if v_original is None:
+            v_original = metadata["original_value"]
+        v_new = metadata["new_value"]
+
+        gas_cost = gas_costs.PAGE_BASE_COST
+
+        page_load_warm = metadata["page_load_warm"] or metadata["key_warm"]
+
+        if not page_load_warm:
+            gas_cost += gas_costs.PAGE_LOAD_COST
+
+        if v_original != v_new:
+            if not metadata["page_write_warm"]:
+                gas_cost += gas_costs.PAGE_WRITE_COST
+
+        current = metadata["current_state_growth"]
+        peak = metadata["net_state_growth"]
+        if v_original == 0 and v_new != 0:
+            current += 1
+        elif v_original != 0 and v_new == 0:
+            current -= 1
+        if current > peak:
+            gas_cost += gas_costs.PAGE_STATE_GROWTH_COST
+
+        return gas_cost
+
+
 class BPO1(
     Osaka,
     bpo_fork=True,

packages/testing/src/execution_testing/forks/forks/transition.py

@@ -7,6 +7,7 @@
     BPO3,
     BPO4,
     MONAD_EIGHT,
+    MONAD_NEXT,
     MONAD_NINE,
     Amsterdam,
     Berlin,
@@ -71,6 +72,13 @@ class MONAD_EIGHTToMONAD_NINEAtTime15k(TransitionBaseClass):  # noqa: N801
     pass
 
 
+@transition_fork(to_fork=MONAD_NEXT, from_fork=MONAD_NINE, at_timestamp=15_000)
+class MONAD_NINEToMONAD_NEXTAtTime15k(TransitionBaseClass):  # noqa: N801
+    """MONAD_NINE to MONAD_NEXT transition at Timestamp 15k."""
+
+    pass
+
+
 @transition_fork(to_fork=BPO1, from_fork=Osaka, at_timestamp=15_000)
 class OsakaToBPO1AtTime15k(TransitionBaseClass):
     """Osaka to BPO1 transition at Timestamp 15k."""

packages/testing/src/execution_testing/forks/gas_costs.py

@@ -146,3 +146,9 @@ class GasCosts:
     OPCODE_BLOBHASH: int = 0
     OPCODE_MCOPY_BASE: int = 0
     OPCODE_CLZ: int = 0
+
+    # MIP-8 page-based storage gas constants
+    PAGE_BASE_COST: int = 0
+    PAGE_LOAD_COST: int = 0
+    PAGE_WRITE_COST: int = 0
+    PAGE_STATE_GROWTH_COST: int = 0