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test_worst_address_state_cold()

Documentation for tests/zkevm/test_worst_stateful_opcodes.py::test_worst_address_state_cold@64f949d0.

Generate fixtures for these test cases for Prague with:

fill -v tests/zkevm/test_worst_stateful_opcodes.py::test_worst_address_state_cold --fork Prague

Test running a block with as many stateful opcodes accessing cold accounts.

Source code in tests/zkevm/test_worst_stateful_opcodes.py 
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@pytest.mark.valid_from("Cancun")
@pytest.mark.parametrize(
    "opcode",
    [
        Op.BALANCE,
    ],
)
@pytest.mark.parametrize(
    "absent_accounts",
    [
        True,
        False,
    ],
)
@pytest.mark.slow()
def test_worst_address_state_cold(
    blockchain_test: BlockchainTestFiller,
    pre: Alloc,
    fork: Fork,
    opcode: Op,
    absent_accounts: bool,
):
    """Test running a block with as many stateful opcodes accessing cold accounts."""
    env = Environment(gas_limit=100_000_000_000)
    attack_gas_limit = Environment().gas_limit

    gas_costs = fork.gas_costs()
    intrinsic_gas_cost_calc = fork.transaction_intrinsic_cost_calculator()
    # For calculation robustness, the calculation below ignores "glue" opcodes like  PUSH and POP.
    # It should be considered a worst-case number of accounts, and a few of them might not be
    # targeted before the attacking transaction runs out of gas.
    num_target_accounts = (
        attack_gas_limit - intrinsic_gas_cost_calc()
    ) // gas_costs.G_COLD_ACCOUNT_ACCESS

    blocks = []
    post = {}

    # Setup
    # The target addresses are going to be constructed (in the case of absent=False) and called
    # as addr_offset + i, where i is the index of the account. This is to avoid
    # collisions with the addresses indirectly created by the testing framework.
    addr_offset = int.from_bytes(pre.fund_eoa(amount=0))

    if not absent_accounts:
        factory_code = Op.PUSH4(num_target_accounts) + While(
            body=Op.POP(Op.CALL(address=Op.ADD(addr_offset, Op.DUP6), value=10)),
            condition=Op.PUSH1(1) + Op.SWAP1 + Op.SUB + Op.DUP1 + Op.ISZERO + Op.ISZERO,
        )
        factory_address = pre.deploy_contract(code=factory_code, balance=10**18)

        setup_tx = Transaction(
            to=factory_address,
            gas_limit=env.gas_limit,
            sender=pre.fund_eoa(),
        )
        blocks.append(Block(txs=[setup_tx]))

        for i in range(num_target_accounts):
            addr = Address(i + addr_offset + 1)
            post[addr] = Account(balance=10)

    # Execution
    op_code = Op.PUSH4(num_target_accounts) + While(
        body=Op.POP(opcode(Op.ADD(addr_offset, Op.DUP1))),
        condition=Op.PUSH1(1) + Op.SWAP1 + Op.SUB + Op.DUP1 + Op.ISZERO + Op.ISZERO,
    )
    op_address = pre.deploy_contract(code=op_code)
    op_tx = Transaction(
        to=op_address,
        gas_limit=attack_gas_limit,
        sender=pre.fund_eoa(),
    )
    blocks.append(Block(txs=[op_tx]))

    blockchain_test(
        genesis_environment=env,
        pre=pre,
        post=post,
        blocks=blocks,
        exclude_full_post_state_in_output=True,
    )

Parametrized Test Cases

The interactive table below is also available as a standalone page.

Test ID (Abbreviated) absent_accounts opcode
...fork_Cancun-blockchain_test-absent_accounts_True-opcode_BALANCE True BALANCE
...fork_Cancun-blockchain_test-absent_accounts_False-opcode_BALANCE False BALANCE
...fork_Prague-blockchain_test-absent_accounts_True-opcode_BALANCE True BALANCE
...fork_Prague-blockchain_test-absent_accounts_False-opcode_BALANCE False BALANCE
...fork_Osaka-blockchain_test-absent_accounts_True-opcode_BALANCE True BALANCE
...fork_Osaka-blockchain_test-absent_accounts_False-opcode_BALANCE False BALANCE