test_top_frame_new_account_charged_as_state_gas()

Documentation for tests/amsterdam/eip2780_reduce_intrinsic_tx_gas/test_top_frame_charges.py::test_top_frame_new_account_charged_as_state_gas@a9abd46e.

Generate fixtures for these test cases for Amsterdam with:

fill -v tests/amsterdam/eip2780_reduce_intrinsic_tx_gas/test_top_frame_charges.py::test_top_frame_new_account_charged_as_state_gas --fork Amsterdam

The top-frame NEW_ACCOUNT charge for a value transfer to an empty recipient is state gas, not regular gas. This pins the dimension via the block header gas_used, which the spec computes as max(block_regular_gas, block_state_gas).

Correctly attributed, the NEW_ACCOUNT state gas dominates the small regular intrinsic, so gas_used == NEW_ACCOUNT. A regression mis-classifying the charge as regular gas would instead yield intrinsic_regular + NEW_ACCOUNT.

state_test-based balance assertions (e.g. test_top_frame_state_charge) only observe the sum of the two dimensions, so they cannot distinguish this; a block-level gas_used assertion is required.

Source code in tests/amsterdam/eip2780_reduce_intrinsic_tx_gas/test_top_frame_charges.py

def test_top_frame_new_account_charged_as_state_gas(
    fork: Fork,
    pre: Alloc,
    blockchain_test: BlockchainTestFiller,
) -> None:
    """
    The top-frame ``NEW_ACCOUNT`` charge for a value transfer to an
    empty recipient is *state* gas, not regular gas. This pins the
    dimension via the block header ``gas_used``, which the spec
    computes as ``max(block_regular_gas, block_state_gas)``.

    Correctly attributed, the ``NEW_ACCOUNT`` state gas dominates the
    small regular intrinsic, so ``gas_used == NEW_ACCOUNT``. A
    regression mis-classifying the charge as regular gas would instead
    yield ``intrinsic_regular + NEW_ACCOUNT``.

    ``state_test``-based balance assertions (e.g.
    ``test_top_frame_state_charge``) only observe the *sum* of the two
    dimensions, so they cannot distinguish this; a block-level
    ``gas_used`` assertion is required.
    """
    sender = pre.fund_eoa(10**18)
    target = pre.fund_eoa(amount=0)
    value = 1

    intrinsic_regular = fork.transaction_intrinsic_cost_calculator()(
        sends_value=True,
        recipient_type=RecipientType.EMPTY_ACCOUNT,
        return_cost_deducted_prior_execution=True,
    )
    new_account_state_gas = fork.transaction_top_frame_state_gas(
        sends_value=True,
        recipient_type=RecipientType.EMPTY_ACCOUNT,
    )
    # The state charge must dominate the regular intrinsic for the
    # header ``gas_used`` to distinguish a state vs regular
    # mis-classification.
    assert new_account_state_gas > intrinsic_regular, (
        "test only distinguishes the dimension when NEW_ACCOUNT "
        f"({new_account_state_gas}) dominates the regular intrinsic "
        f"({intrinsic_regular})"
    )

    # No EVM bytecode runs (empty recipient), so the only regular gas
    # is the intrinsic and the only state gas is the top-frame
    # ``NEW_ACCOUNT`` charge.
    expected_gas_used = max(intrinsic_regular, new_account_state_gas)

    gas_price = 1_000_000_000
    tx = Transaction(
        sender=sender,
        to=target,
        value=value,
        gas_limit=intrinsic_regular + new_account_state_gas + 1000,
        gas_price=gas_price,
    )

    blockchain_test(
        pre=pre,
        blocks=[
            Block(
                txs=[tx],
                header_verify=Header(gas_used=expected_gas_used),
            ),
        ],
        post={
            sender: Account(nonce=1),
            target: Account(balance=value),
        },
    )

Parametrized Test Cases

This test generates 1 parametrized test case across 1 fork.