test_same_frame_refund_increases_gas_left()

Documentation for tests/amsterdam/eip8037_state_creation_gas_cost_increase/test_state_gas_cross_frame_refund.py::test_same_frame_refund_increases_gas_left@622620d8.

Generate fixtures for these test cases for Amsterdam with:

fill -v tests/amsterdam/eip8037_state_creation_gas_cost_increase/test_state_gas_cross_frame_refund.py::test_same_frame_refund_increases_gas_left --fork Amsterdam

Test a same-frame refill can increase gas_left between reads.

This is the local control for the cross-frame behavior: a fresh set spills from gas_left, the first measured window clears it in the same frame, and the second repeats the clear as a no-op. The two windows have identical bytecode and execution cost, so their exact difference is the repaid spill. With half a slot funded by the reservoir, only half of the full-slot refund repays the spill.

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

@pytest.mark.parametrize(
    "fund_half_slot",
    [False, True],
    ids=["empty-reservoir", "half-slot-reservoir"],
)
@pytest.mark.valid_from("EIP8037")
def test_same_frame_refund_increases_gas_left(
    state_test: StateTestFiller,
    pre: Alloc,
    fork: Fork,
    fund_half_slot: bool,
) -> None:
    """
    Test a same-frame refill can increase `gas_left` between reads.

    This is the local control for the cross-frame behavior: a fresh set
    spills from `gas_left`, the first measured window clears it in the
    same frame, and the second repeats the clear as a no-op. The two
    windows have identical bytecode and execution cost, so their exact
    difference is the repaid spill. With half a slot funded by the
    reservoir, only half of the full-slot refund repays the spill.
    """
    sstore_state_gas = Op.SSTORE(new_value=1).state_cost(fork)
    reservoir = sstore_state_gas // 2 if fund_half_slot else 0
    spilled = sstore_state_gas - reservoir

    window = Op.SSTORE(SLOT_X, 0)
    contract = pre.deploy_contract(
        code=clearing_probe_code(FRESH_SET(SLOT_X, 1), [window] * 3)
    )

    tx = Transaction(
        to=contract,
        state_gas_reservoir=reservoir,
        sender=pre.fund_eoa(),
    )

    post = {
        contract: Account(
            storage={
                SLOT_X: 0,
                SLOT_MARKER: 1,
                SLOT_INCREASED: 1,
                SLOT_RESULT: -spilled,
            }
        )
    }
    state_test(pre=pre, post=post, tx=tx)

Parametrized Test Cases

This test generates 2 parametrized test cases across 1 fork.