test_no_account_charge_on_existing_account()

Documentation for tests/amsterdam/eip8037_state_creation_gas_cost_increase/test_state_gas_create.py::test_no_account_charge_on_existing_account@26332146.

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_no_account_charge_on_existing_account --fork Amsterdam

Verify the create opcode is not charged NEW_ACCOUNT when the target account already exists in the trie.

The factory is forwarded exactly the create's execution gas, with no NEW_ACCOUNT included. Because the target is pre-funded (alive), that budget is sufficient and the create succeeds, deploying empty code (created nonce 1). With one gas less it runs out of gas at the create's upfront charge, before the nonce bump, leaving the target untouched (nonce 0). The empty reservoir keeps the state-gas dimension from masking the boundary.

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

@pytest.mark.with_all_create_opcodes()
@pytest.mark.parametrize(
    "sufficient_gas",
    [
        pytest.param(True, id="sufficient_gas"),
        pytest.param(False, id="insufficient_gas"),
    ],
)
@pytest.mark.valid_from("EIP8037")
def test_no_account_charge_on_existing_account(
    state_test: StateTestFiller,
    pre: Alloc,
    fork: Fork,
    create_opcode: Op,
    sufficient_gas: bool,
) -> None:
    """
    Verify the create opcode is not charged NEW_ACCOUNT when the target
    account already exists in the trie.

    The factory is forwarded exactly the create's execution gas, with no
    NEW_ACCOUNT included. Because the target is pre-funded (alive), that
    budget is sufficient and the create succeeds, deploying empty code
    (created nonce 1). With one gas less it runs out of gas at the
    create's upfront charge, before the nonce bump, leaving the target
    untouched (nonce 0). The empty reservoir keeps the state-gas
    dimension from masking the boundary.
    """
    factory_code = create_opcode(
        value=0,
        offset=0,
        size=1,  # Nothing in memory, equivalent to Op.STOP
        # Gas accounting
        init_code_size=1,
        new_memory_size=1,
        account_new=False,
    )

    factory = pre.deploy_contract(code=factory_code)

    created = compute_create_address(
        address=factory,
        nonce=1,
        salt=0,
        initcode=Op.STOP,
        opcode=create_opcode,
    )
    pre.fund_address(created, amount=1)

    call_gas = factory_code.gas_cost(fork)
    if not sufficient_gas:
        call_gas -= 1
    entry_code = Op.CALL(gas=call_gas, address=factory)
    entry = pre.deploy_contract(code=entry_code)

    tx = Transaction(
        to=entry,
        state_gas_reservoir=0,  # To allow subcall to run OOG
        sender=pre.fund_eoa(),
    )

    post = {
        created: Account(
            nonce=1 if sufficient_gas else 0, balance=1, code=b""
        ),
    }
    state_test(pre=pre, post=post, tx=tx)

Parametrized Test Cases

This test generates 4 parametrized test cases across 1 fork.