test_codecopy_zero_in_create2()

Documentation for tests/constantinople/eip1052_extcodehash/test_extcodehash.py::test_codecopy_zero_in_create2@b47f0253.

Generate fixtures for these test cases for Amsterdam with:

fill -v tests/constantinople/eip1052_extcodehash/test_extcodehash.py::test_codecopy_zero_in_create2 --fork Amsterdam

Test CODECOPY inside CREATE2 initcode that deploys empty code.

The initcode does CODECOPY(0,0,32) which copies the first 32 bytes of the initcode itself (not the deployed code). It then checks EXTCODESIZE(ADDRESS) and EXTCODEHASH(ADDRESS) of self during init, which see the account as having empty code. The deployed contract retains the storage set during init.

Source code in tests/constantinople/eip1052_extcodehash/test_extcodehash.py

@pytest.mark.ported_from(
    [
        "https://github.com/ethereum/tests/blob/v13.3/src/GeneralStateTestsFiller/stExtCodeHash/codeCopyZero_ParisFiller.yml",  # noqa: E501
    ],
)
def test_codecopy_zero_in_create2(
    state_test: StateTestFiller,
    pre: Alloc,
) -> None:
    """
    Test CODECOPY inside CREATE2 initcode that deploys empty code.

    The initcode does CODECOPY(0,0,32) which copies the first 32 bytes
    of the initcode itself (not the deployed code). It then checks
    EXTCODESIZE(ADDRESS) and EXTCODEHASH(ADDRESS) of self during init,
    which see the account as having empty code. The deployed contract
    retains the storage set during init.
    """
    storage = Storage()

    # Build the initcode that queries itself and deploys empty code.
    # During init: CODECOPY copies the initcode, EXTCODESIZE(self)=0,
    # EXTCODEHASH(self)=keccak256("").
    initcode = (
        Op.CODECOPY(0, 0, 32)
        + Op.SSTORE(0x50, Op.MLOAD(0))
        + Op.SSTORE(0x51, Op.EXTCODESIZE(Op.ADDRESS))
        + Op.SSTORE(0x52, Op.EXTCODEHASH(Op.ADDRESS))
        + Op.SSTORE(
            0x53,
            Op.EXTCODESIZE(Op.CALLCODE(50_000, Op.ADDRESS, 0, 0, 0, 0, 0)),
        )
        + Op.EXTCODECOPY(Op.ADDRESS, 0, 0, 32)
        + Op.SSTORE(0x54, Op.MLOAD(0))
        # Return empty code (size 0).
        + Op.RETURN(0, 0)
    )

    # Factory: CREATE2 and return the created address.
    factory_code = (
        Om.MSTORE(initcode, 0)
        + Op.MSTORE(
            0,
            Op.CREATE2(value=0, offset=0, size=len(initcode), salt=0),
        )
        + Op.RETURN(0, 32)
    )

    factory = pre.deploy_contract(factory_code, balance=10**18)

    # Caller: invoke factory and store created address.
    caller_code = Op.CALL(550_000, factory, 0, 0, 0, 0, 32) + Op.SSTORE(
        storage.store_next(0, "created_address"), Op.MLOAD(0)
    )

    caller = pre.deploy_contract(caller_code, storage=storage.canary())

    created = compute_create2_address(
        address=factory, salt=0, initcode=initcode
    )
    storage[0] = created

    # First 32 bytes of initcode — what CODECOPY(0,0,32) returns.
    initcode_word0 = bytes(initcode)[:32]

    tx = Transaction(
        sender=pre.fund_eoa(),
        to=caller,
        gas_limit=1_400_000,
    )

    state_test(
        pre=pre,
        post={
            caller: Account(storage=storage),
            created: Account(
                nonce=1,
                code=b"",
                storage={
                    0x50: initcode_word0,
                    0x51: 0,
                    0x52: keccak256(b""),
                    0x53: 0,
                    0x54: 0,
                },
            ),
        },
        tx=tx,
    )

Parametrized Test Cases

This test generates 1 parametrized test case across 10 forks.