feat(tests): Add tests for OOGing in EXP variable gas

Author: pdobacz

tests/frontier/opcodes/test_all_opcodes.py

@@ -306,6 +306,7 @@ def test_constant_gas(
         + (code_increment_counter if opcode == Op.CREATE2 else Bytecode())
     )
     gas_test(
+        fork,
         state_test,
         env,
         pre,

tests/frontier/opcodes/test_exp.py

@@ -0,0 +1,68 @@
+"""
+Test EXP opcode.
+"""
+
+import pytest
+from execution_testing import (
+    Alloc,
+    Environment,
+    StateTestFiller,
+)
+from execution_testing.base_types.base_types import ZeroPaddedHexNumber
+from execution_testing.forks.helpers import Fork
+from execution_testing.vm import Opcodes as Op
+
+from tests.unscheduled.eip7692_eof_v1.gas_test import gas_test
+
+REFERENCE_SPEC_GIT_PATH = "N/A"
+REFERENCE_SPEC_VERSION = "N/A"
+
+
+def exp_gas(fork: Fork, exponent: int) -> int:
+    """Calculate gas cost for EXP opcode given the exponent."""
+    byte_len = (exponent.bit_length() + 7) // 8
+    return fork.gas_costs().G_EXP + fork.gas_costs().G_EXP_BYTE * byte_len
+
+
+@pytest.mark.valid_from("Berlin")
+@pytest.mark.parametrize(
+    "a", [0, 1, pytest.param(2**256 - 1, id="a2to256minus1")]
+)
+@pytest.mark.parametrize(
+    "exponent",
+    [
+        0,
+        1,
+        2,
+        1023,
+        1024,
+        pytest.param(2**255, id="exponent2to255"),
+        pytest.param(2**256 - 1, id="exponent2to256minus1"),
+    ],
+)
+def test_gas(
+    state_test: StateTestFiller,
+    pre: Alloc,
+    a: int,
+    exponent: int,
+    fork: Fork,
+    env: Environment,
+) -> None:
+    """Test that EXP gas works as expected."""
+    warm_gas = exp_gas(fork, exponent)
+
+    if cap := fork.transaction_gas_limit_cap():
+        env.gas_limit = ZeroPaddedHexNumber(cap)
+
+    gas_test(
+        fork,
+        state_test,
+        env,
+        pre,
+        setup_code=Op.PUSH32(exponent) + Op.PUSH32(a),
+        subject_code=Op.EXP,
+        tear_down_code=Op.STOP,
+        cold_gas=warm_gas,
+        warm_gas=warm_gas,
+        eof=False,
+    )

tests/unscheduled/eip7692_eof_v1/eip7069_extcall/test_gas.py

@@ -143,6 +143,7 @@ def test_ext_calls_gas(
     )
     cost_memory_bytes = fork.memory_expansion_gas_calculator()
     gas_test(
+        fork,
         state_test,
         state_env,
         pre,
@@ -164,6 +165,7 @@ def test_ext_calls_gas(
 def test_transfer_gas_is_cleared(
     state_test: StateTestFiller,
     pre: Alloc,
+    fork: Fork,
     state_env: Environment,
     opcode: Op,
     value: int,
@@ -185,6 +187,7 @@ def test_transfer_gas_is_cleared(
     push_gas = (4 if opcode == Op.EXTCALL else 3) * 3
 
     gas_test(
+        fork,
         state_test,
         state_env,
         pre,
@@ -212,6 +215,7 @@ def test_transfer_gas_is_cleared(
 def test_late_account_create(
     state_test: StateTestFiller,
     pre: Alloc,
+    fork: Fork,
     state_env: Environment,
     opcode: Op,
 ) -> None:
@@ -222,6 +226,7 @@ def test_late_account_create(
     empty_address = Address(0xDECAFC0DE)
 
     gas_test(
+        fork,
         state_test,
         state_env,
         pre,

tests/unscheduled/eip7692_eof_v1/eip7620_eof_create/test_gas.py

@@ -149,6 +149,7 @@ def test_eofcreate_gas(
     )
     cost_memory_bytes = fork.memory_expansion_gas_calculator()
     gas_test(
+        fork,
         state_test,
         Environment(),
         pre,

tests/unscheduled/eip7692_eof_v1/gas_test.py

@@ -13,6 +13,8 @@
     StateTestFiller,
     Transaction,
 )
+from execution_testing.forks.forks.forks import Berlin
+from execution_testing.forks.helpers import Fork
 from execution_testing.test_types.eof.v1 import Container, Section
 
 from .eip7069_extcall.spec import (
@@ -31,6 +33,7 @@
 
 
 def gas_test(
+    fork: Fork,
     state_test: StateTestFiller,
     env: Environment,
     pre: Alloc,
@@ -55,6 +58,11 @@ def gas_test(
     test, and MUST NOT have any side-effects which persist across message
     calls, and in particular, any effects on the gas usage of `subject_code`.
     """
+    if fork < Berlin:
+        raise ValueError(
+            "Gas tests before Berlin are not supported due to CALL gas changes"
+        )
+
     if cold_gas <= 0:
         raise ValueError(
             f"Target gas allocations (cold_gas) must be > 0, got {cold_gas}"