test_bal_cross_tx_storage_revert_to_zero()

Documentation for tests/amsterdam/eip7928_block_level_access_lists/test_block_access_lists.py::test_bal_cross_tx_storage_revert_to_zero@892e6d1e.

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_cross_tx_storage_revert_to_zero --fork Amsterdam

Ensure BAL captures storage changes when tx1 writes a non-zero value and tx2 reverts it back to zero. This is a regression test for the blobhash scenario where slot changes were being incorrectly filtered as net-zero across transaction boundaries.

Tx1: slot 0 = 0x0 -> 0xABCD (change at block_access_index=1) Tx2: slot 0 = 0xABCD -> 0x0 (change MUST be at block_access_index=2)

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

def test_bal_cross_tx_storage_revert_to_zero(
    pre: Alloc,
    blockchain_test: BlockchainTestFiller,
) -> None:
    """
    Ensure BAL captures storage changes when tx1 writes a non-zero value
    and tx2 reverts it back to zero. This is a regression test for the
    blobhash scenario where slot changes were being incorrectly filtered
    as net-zero across transaction boundaries.

    Tx1: slot 0 = 0x0 -> 0xABCD (change at block_access_index=1)
    Tx2: slot 0 = 0xABCD -> 0x0 (change MUST be at block_access_index=2)
    """
    alice = pre.fund_eoa()

    # Contract that writes to slot 0 based on calldata
    contract = pre.deploy_contract(code=Op.SSTORE(0, Op.CALLDATALOAD(0)))

    # Tx1: Write slot 0 = 0xABCD
    tx1 = Transaction(
        sender=alice,
        to=contract,
        data=Hash(0xABCD),
        gas_limit=100_000,
    )

    # Tx2: Write slot 0 = 0x0 (revert to zero)
    tx2 = Transaction(
        sender=alice,
        to=contract,
        data=Hash(0x0),
        gas_limit=100_000,
    )

    account_expectations = {
        alice: BalAccountExpectation(
            nonce_changes=[
                BalNonceChange(block_access_index=1, post_nonce=1),
                BalNonceChange(block_access_index=2, post_nonce=2),
            ],
        ),
        contract: BalAccountExpectation(
            storage_changes=[
                BalStorageSlot(
                    slot=0,
                    slot_changes=[
                        BalStorageChange(
                            block_access_index=1, post_value=0xABCD
                        ),
                        # CRITICAL: tx2's write to 0x0 MUST appear
                        # even though it returns slot to original value
                        BalStorageChange(block_access_index=2, post_value=0x0),
                    ],
                ),
            ],
        ),
    }

    blockchain_test(
        pre=pre,
        blocks=[
            Block(
                txs=[tx1, tx2],
                expected_block_access_list=BlockAccessListExpectation(
                    account_expectations=account_expectations
                ),
            )
        ],
        post={
            alice: Account(nonce=2),
            contract: Account(storage={0: 0x0}),
        },
    )

Parametrized Test Cases

This test generates 1 parametrized test case across 1 fork.