test_bal_many_storage_writes_single_account()

Documentation for tests/amsterdam/eip7928_block_level_access_lists/test_block_access_lists.py::test_bal_many_storage_writes_single_account@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_many_storage_writes_single_account --fork Amsterdam

Verify the BAL records many distinct storage changes for a single account written by a single transaction.

One transaction calls a contract that writes num_slots distinct, previously-zero slots (slot[i] = i + 1 for i in 0..num_slots). The account's storage_changes in the BAL must list every slot, in ascending slot order, each at block_access_index=1.

Existing BAL storage tests touch at most a handful of slots per account (e.g. test_bal_cross_tx_storage_chain writes 8 slots, one per transaction). This exercises a much higher per-account, per-transaction storage-change cardinality, which stresses any client that records or preloads an account's BAL storage keys into a fixed-size buffer.

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

@pytest.mark.parametrize(
    "num_slots",
    [
        pytest.param(17, id="17_slots"),
        pytest.param(32, id="32_slots"),
        pytest.param(128, id="128_slots"),
    ],
)
def test_bal_many_storage_writes_single_account(
    pre: Alloc,
    blockchain_test: BlockchainTestFiller,
    fork: Fork,
    num_slots: int,
) -> None:
    """
    Verify the BAL records many distinct storage changes for a single
    account written by a single transaction.

    One transaction calls a contract that writes `num_slots` distinct,
    previously-zero slots (`slot[i] = i + 1` for `i` in `0..num_slots`).
    The account's `storage_changes` in the BAL must list every slot, in
    ascending slot order, each at `block_access_index=1`.

    Existing BAL storage tests touch at most a handful of slots per
    account (e.g. `test_bal_cross_tx_storage_chain` writes 8 slots, one
    per transaction). This exercises a much higher per-account,
    per-transaction storage-change cardinality, which stresses any client
    that records or preloads an account's BAL storage keys into a
    fixed-size buffer.
    """
    contract_code = Op.SSTORE(0, 1)
    for i in range(1, num_slots):
        contract_code += Op.SSTORE(i, i + 1)
    contract_code += Op.STOP
    contract = pre.deploy_contract(code=contract_code)

    alice = pre.fund_eoa()
    tx = Transaction(
        sender=alice,
        to=contract,
        gas_limit=fork.transaction_gas_limit_cap(),
    )

    account_expectations = {
        alice: BalAccountExpectation(
            nonce_changes=[BalNonceChange(block_access_index=1, post_nonce=1)],
        ),
        contract: BalAccountExpectation(
            storage_changes=[
                BalStorageSlot(
                    slot=i,
                    slot_changes=[
                        BalStorageChange(
                            block_access_index=1, post_value=i + 1
                        )
                    ],
                )
                for i in range(num_slots)
            ],
            storage_reads=[],
        ),
    }

    blockchain_test(
        pre=pre,
        blocks=[
            Block(
                txs=[tx],
                expected_block_access_list=BlockAccessListExpectation(
                    account_expectations=account_expectations
                ),
            )
        ],
        post={
            contract: Account(storage={i: i + 1 for i in range(num_slots)}),
        },
    )

Parametrized Test Cases

This test generates 3 parametrized test cases across 1 fork.