test_create_address_nonce_boundary()

Documentation for tests/frontier/create/test_create_preimage_layout.py::test_create_address_nonce_boundary@b314d18e.

Generate fixtures for these test cases for Amsterdam with:

fill -v tests/frontier/create/test_create_preimage_layout.py::test_create_address_nonce_boundary --fork Amsterdam

Verify CreatePreimageLayout at RLP encoding size boundaries.

Deploy a contract at an address whose first and last bytes are zero, with a prestate nonce set to starting_nonce. Run CREATE in a loop for a small number of iterations, verifying each computed address matches the actual one.

Each boundary value is the last nonce before the RLP encoding grows by one byte.

Source code in tests/frontier/create/test_create_preimage_layout.py

@pytest.mark.parametrize(
    "starting_nonce",
    [
        pytest.param(1, id="nonce_1_initial_value"),
        pytest.param(127, id="nonce_127_max_single_byte"),
        pytest.param(255, id="nonce_max_1_byte_value"),
        pytest.param(256**2 - 1, id="nonce_max_2_byte_value"),
        pytest.param(256**3 - 1, id="nonce_max_3_byte_value"),
        pytest.param(256**4 - 1, id="nonce_max_4_byte_value"),
        pytest.param(256**5 - 1, id="nonce_max_5_byte_value"),
        pytest.param(256**6 - 1, id="nonce_max_6_byte_value"),
        pytest.param(256**7 - 1, id="nonce_max_7_byte_value"),
    ],
)
@pytest.mark.pre_alloc_mutable
@pytest.mark.valid_from("Osaka")
def test_create_address_nonce_boundary(
    pre: Alloc,
    state_test: StateTestFiller,
    starting_nonce: int,
) -> None:
    """
    Verify CreatePreimageLayout at RLP encoding size boundaries.

    Deploy a contract at an address whose first and last bytes are
    zero, with a prestate nonce set to ``starting_nonce``.  Run
    CREATE in a loop for a small number of iterations, verifying
    each computed address matches the actual one.

    Each boundary value is the last nonce before the RLP encoding
    grows by one byte.
    """
    # EVM does not allow nonces higher than 8 bytes, so a PUSH8 will always fit
    nonce_push = Op.PUSH8(starting_nonce)

    layout = CreatePreimageLayout(
        sender_address=Op.ADDRESS,
        nonce=nonce_push,
        offset=32,
    )

    body = (
        Conditional(
            condition=Op.EQ(
                layout.address_op(),
                Op.CREATE(value=0, offset=0, size=0),
            ),
            if_false=Op.REVERT(0, 0),
        )
        + layout.increment_nonce_op()
        + Op.MSTORE(0, Op.SUB(Op.MLOAD(0), 1))
    )

    code: Bytecode = layout
    code += Op.MSTORE(0, BOUNDARY_ITERATIONS)
    code += While(body=body, condition=Op.MLOAD(0))
    code += Op.SSTORE(0, 1)
    code += Op.STOP

    pre.deploy_contract(
        code=code,
        address=DEPLOYER_ADDRESS,
        nonce=starting_nonce,
    )
    sender = pre.fund_eoa()

    tx = Transaction(to=DEPLOYER_ADDRESS, sender=sender)

    post = {DEPLOYER_ADDRESS: Account(storage={0: 1})}
    for nonce in range(starting_nonce, starting_nonce + BOUNDARY_ITERATIONS):
        created = compute_create_address(address=DEPLOYER_ADDRESS, nonce=nonce)
        post[created] = Account(nonce=1)

    state_test(pre=pre, tx=tx, post=post)

Parametrized Test Cases

This test generates 9 parametrized test cases across 2 forks.