test_recursive_revert_returns_reservoir()

Documentation for tests/amsterdam/eip8037_state_creation_gas_cost_increase/test_state_gas_call.py::test_recursive_revert_returns_reservoir@622620d8.

Generate fixtures for these test cases for Amsterdam with:

fill -v tests/amsterdam/eip8037_state_creation_gas_cost_increase/test_state_gas_call.py::test_recursive_revert_returns_reservoir --fork Amsterdam

Test a deep self-recursing call chain returns the reservoir.

Each frame recurses while it has the gas to, and the bottom one instead draws the whole reservoir for an SSTORE and reverts, restoring it. A probe in the top frame, handed only its SSTORE's execution cost, then succeeds only if that restore travelled back up the entire unwind.

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

@pytest.mark.valid_from("EIP8037")
def test_recursive_revert_returns_reservoir(
    state_test: StateTestFiller,
    pre: Alloc,
    fork: Fork,
) -> None:
    """
    Test a deep self-recursing call chain returns the reservoir.

    Each frame recurses while it has the gas to, and the bottom one
    instead draws the whole reservoir for an SSTORE and reverts,
    restoring it. A probe in the top frame, handed only its SSTORE's
    execution cost, then succeeds only if that restore travelled back
    up the entire unwind.
    """
    sstore_state_gas = Op.SSTORE(new_value=1).state_cost(fork)

    # Recurse while there is comfortably more gas than the bottom frame
    # needs. Gas shrinks by only 1/64 per level, so the frame that first
    # falls below the threshold still holds well over `bottom_gas`.
    bottom = Op.SSTORE(0, 1) + Op.REVERT(0, 0)
    bottom_gas = bottom.execution_cost(fork)
    driver_code = Conditional(
        condition=Op.GT(Op.GAS, 2 * bottom_gas),
        if_true=Op.POP(Op.CALL(Op.GAS, Op.ADDRESS, 0, 0, 0, 0, 0)),
        if_false=bottom,
    )
    driver = pre.deploy_contract(code=driver_code)

    probe_code = Op.SSTORE(0, 1)
    probe = pre.deploy_contract(code=probe_code)
    probe_gas = probe_code.execution_cost(fork)

    storage = Storage()
    probe_slot = storage.store_next(1, "probe_succeeds")
    caller_code = Op.POP(Op.CALL(gas=Op.GAS, address=driver)) + Op.SSTORE(
        probe_slot,
        Op.CALL(gas=probe_gas, address=probe),
        # gas accounting
        original_value=1,
        current_value=1,
        new_value=1,
        key_warm=False,
    )
    caller = pre.deploy_contract(code=caller_code, storage={probe_slot: 1})

    tx = Transaction(
        to=caller,
        state_gas_reservoir=sstore_state_gas,
        sender=pre.fund_eoa(),
    )

    post = {
        caller: Account(storage=storage),
        probe: Account(storage={0: 1}),
    }
    state_test(pre=pre, post=post, tx=tx)

Parametrized Test Cases

This test generates 1 parametrized test case across 1 fork.