test_bal_nonexistent_account_access_value_transfer()

Documentation for tests/amsterdam/eip7928_block_level_access_lists/test_block_access_lists.py::test_bal_nonexistent_account_access_value_transfer@87aba1a3.

Generate fixtures for these test cases for Amsterdam with:

fill -v tests/amsterdam/eip7928_block_level_access_lists/test_block_access_lists.py::test_bal_nonexistent_account_access_value_transfer --fork Amsterdam

Ensure BAL captures non-existent account access via CALL/CALLCODE with value.

Alice calls Oracle contract which uses CALL or CALLCODE to access non-existent Bob with value transfer. - CALL: Transfers value from Oracle to Bob - CALLCODE: Self-transfer (net zero), Bob accessed for code

Source code in tests/amsterdam/eip7928_block_level_access_lists/test_block_access_lists.py

@pytest.mark.parametrize(
    "opcode",
    [
        pytest.param(Op.CALL),
        pytest.param(Op.CALLCODE),
    ],
)
@pytest.mark.parametrize(
    "value",
    [
        pytest.param(0, id="zero_value"),
        pytest.param(10**18, id="positive_value"),
    ],
)
def test_bal_nonexistent_account_access_value_transfer(
    pre: Alloc,
    blockchain_test: BlockchainTestFiller,
    opcode: Op,
    value: int,
) -> None:
    """
    Ensure BAL captures non-existent account access via CALL/CALLCODE
    with value.

    Alice calls Oracle contract which uses CALL or CALLCODE to access
    non-existent Bob with value transfer.
    - CALL: Transfers value from Oracle to Bob
    - CALLCODE: Self-transfer (net zero), Bob accessed for code
    """
    alice = pre.fund_eoa()
    bob = pre.nonexistent_account()
    oracle_balance = value + 10**18

    oracle_code = opcode(gas=0, address=bob, value=value)

    oracle = pre.deploy_contract(code=oracle_code, balance=oracle_balance)

    tx = Transaction(sender=alice, to=oracle)

    # Calculate expected balances
    if opcode == Op.CALL and value > 0:
        # CALL: Oracle loses value, Bob gains value
        oracle_final_balance = oracle_balance - value
        bob_final_balance = value
        bob_has_balance_change = True
        oracle_has_balance_change = True
    elif opcode == Op.CALLCODE and value > 0:
        # CALLCODE: Self-transfer (net zero), Bob just accessed for code
        oracle_final_balance = oracle_balance
        bob_final_balance = 0
        bob_has_balance_change = False
        oracle_has_balance_change = False
    else:
        # Zero value
        oracle_final_balance = oracle_balance
        bob_final_balance = 0
        bob_has_balance_change = False
        oracle_has_balance_change = False

    block = Block(
        txs=[tx],
        expected_block_access_list=BlockAccessListExpectation(
            account_expectations={
                alice: BalAccountExpectation(
                    nonce_changes=[
                        BalNonceChange(block_access_index=1, post_nonce=1)
                    ],
                ),
                oracle: BalAccountExpectation(
                    balance_changes=[
                        BalBalanceChange(
                            block_access_index=1,
                            post_balance=oracle_final_balance,
                        )
                    ]
                    if oracle_has_balance_change
                    else [],
                ),
                bob: BalAccountExpectation(
                    balance_changes=[
                        BalBalanceChange(
                            block_access_index=1,
                            post_balance=bob_final_balance,
                        )
                    ]
                    if bob_has_balance_change
                    else [],
                ),
            }
        ),
    )

    blockchain_test(
        pre=pre,
        blocks=[block],
        post={
            alice: Account(nonce=1),
            oracle: Account(balance=oracle_final_balance),
            bob: Account(balance=bob_final_balance)
            if bob_has_balance_change
            else Account.NONEXISTENT,
        },
    )

Parametrized Test Cases

This test generates 4 parametrized test cases across 1 fork.