test_create_child_revert_refunds_state_gas()

Documentation for tests/amsterdam/eip8037_state_creation_gas_cost_increase/test_state_gas_create.py::test_create_child_revert_refunds_state_gas@c74f1a67.

Generate fixtures for these test cases for Amsterdam with:

fill -v tests/amsterdam/eip8037_state_creation_gas_cost_increase/test_state_gas_create.py::test_create_child_revert_refunds_state_gas --fork Amsterdam

Verify CREATE/CREATE2 child REVERT refunds parent's account gas.

On REVERT the parent's GAS_NEW_ACCOUNT charge is refunded to the reservoir (on top of the child's state gas returned via incorporate_child_on_error). Block state gas reflects only the probe SSTORE. The spillover variant runs with tx.gas at the cap (reservoir zero), so the state gas charge spills into gas_left and the refund returns to the reservoir (not back to gas_left).

Source code in tests/amsterdam/eip8037_state_creation_gas_cost_increase/test_state_gas_create.py

@pytest.mark.parametrize(
    "gas_limit_mode",
    [
        pytest.param("reservoir", id="with_reservoir"),
        pytest.param("spillover", id="spillover"),
    ],
)
@pytest.mark.with_all_create_opcodes()
@pytest.mark.valid_from("EIP8037")
def test_create_child_revert_refunds_state_gas(
    blockchain_test: BlockchainTestFiller,
    pre: Alloc,
    fork: Fork,
    create_opcode: Op,
    gas_limit_mode: str,
) -> None:
    """
    Verify CREATE/CREATE2 child REVERT refunds parent's account gas.

    On REVERT the parent's `GAS_NEW_ACCOUNT` charge is refunded to
    the reservoir (on top of the child's state gas returned via
    `incorporate_child_on_error`). Block state gas reflects only the
    probe SSTORE. The spillover variant runs with tx.gas at the cap
    (reservoir zero), so the state gas charge spills into `gas_left`
    and the refund returns to the reservoir (not back to `gas_left`).
    """
    gas_limit_cap = fork.transaction_gas_limit_cap()
    assert gas_limit_cap is not None
    gas_costs = fork.gas_costs()
    sstore_state_gas = Op.SSTORE(new_value=1).state_cost(fork)
    intrinsic_cost = fork.transaction_intrinsic_cost_calculator()()

    init_code = Op.REVERT(0, 0)
    mstore_value, size = init_code_at_high_bytes(init_code)

    create_call = (
        create_opcode(value=0, offset=0, size=size, salt=0)
        if create_opcode == Op.CREATE2
        else create_opcode(value=0, offset=0, size=size)
    )

    storage = Storage()
    factory_code = (
        Op.MSTORE(0, mstore_value)
        + Op.POP(create_call)
        + Op.SSTORE(storage.store_next(1, "reservoir_ok"), 1)
    )
    factory = pre.deploy_contract(code=factory_code)

    gas_limit = (
        gas_limit_cap
        if gas_limit_mode == "spillover"
        else gas_limit_cap + sstore_state_gas
    )
    tx = Transaction(
        to=factory,
        gas_limit=gas_limit,
        sender=pre.fund_eoa(),
    )

    # CREATE's GAS_NEW_ACCOUNT is refunded on child REVERT. SSTORE's
    # state portion is tracked separately. Child REVERT regular
    # (init_code execution) is propagated via
    # incorporate_child_on_error.
    tx_regular = (
        intrinsic_cost
        + factory_code.gas_cost(fork)
        - gas_costs.NEW_ACCOUNT
        - sstore_state_gas
        + init_code.gas_cost(fork)
    )
    tx_state = sstore_state_gas
    expected = max(tx_regular, tx_state)
    blockchain_test(
        pre=pre,
        blocks=[Block(txs=[tx], header_verify=Header(gas_used=expected))],
        post={factory: Account(storage=storage)},
    )

Parametrized Test Cases

This test generates 4 parametrized test cases across 1 fork.