test_create2_address_collision()

Documentation for tests/amsterdam/eip8037_state_creation_gas_cost_increase/test_state_gas_create.py::test_create2_address_collision@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_create2_address_collision --fork Amsterdam

Test CREATE2 returns zero on address collision.

When CREATE2 targets an address that already has code or storage, the collision is detected early and returns zero without charging state gas. The existing account is left unchanged.

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

@pytest.mark.valid_from("EIP8037")
def test_create2_address_collision(
    state_test: StateTestFiller,
    pre: Alloc,
    fork: Fork,
) -> None:
    """
    Test CREATE2 returns zero on address collision.

    When CREATE2 targets an address that already has code or storage,
    the collision is detected early and returns zero without charging
    state gas. The existing account is left unchanged.
    """
    gas_limit_cap = fork.transaction_gas_limit_cap()
    assert gas_limit_cap is not None
    init_code = Op.STOP
    salt = 0

    storage = Storage()
    contract = pre.deploy_contract(
        code=(
            Op.MSTORE(
                0,
                int.from_bytes(bytes(init_code), "big")
                << (256 - 8 * len(init_code)),
            )
            # First CREATE2 succeeds
            + Op.SSTORE(
                storage.store_next(1, "first_create2"),
                Op.ISZERO(Op.ISZERO(Op.CREATE2(0, 0, len(init_code), salt))),
            )
            # Second CREATE2 with same salt collides
            + Op.SSTORE(
                storage.store_next(0, "collision_create2"),
                Op.CREATE2(0, 0, len(init_code), salt),
            )
        ),
    )

    tx = Transaction(
        to=contract,
        gas_limit=gas_limit_cap * 2,
        sender=pre.fund_eoa(),
    )

    post = {contract: Account(storage=storage)}
    state_test(pre=pre, post=post, tx=tx)

Parametrized Test Cases

This test generates 1 parametrized test case across 1 fork.