test_sstore_restoration_refund_credits_local_reservoir()

Documentation for tests/amsterdam/eip8037_state_creation_gas_cost_increase/test_state_gas_sstore.py::test_sstore_restoration_refund_credits_local_reservoir@5c024cbb.

Generate fixtures for these test cases for Amsterdam with:

fill -v tests/amsterdam/eip8037_state_creation_gas_cost_increase/test_state_gas_sstore.py::test_sstore_restoration_refund_credits_local_reservoir --fork Amsterdam

Verify a same transaction SSTORE restoration refund credits the clearing frame's own reservoir immediately so later state gas in that frame is funded. Parametrized to pin the refund as necessary and sufficient.

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

@pytest.mark.parametrize(
    "refund_sufficient",
    [
        pytest.param(True, id="refund_funds_create"),
        pytest.param(False, id="no_refund_create_oogs"),
    ],
)
@pytest.mark.parametrize(
    "delegatecall_depth",
    [
        pytest.param(1, id="depth_1"),
        pytest.param(3, id="depth_3"),
        pytest.param(10, id="depth_10"),
    ],
)
@pytest.mark.valid_from("EIP8037")
def test_sstore_restoration_refund_credits_local_reservoir(
    state_test: StateTestFiller,
    pre: Alloc,
    fork: Fork,
    delegatecall_depth: int,
    refund_sufficient: bool,
) -> None:
    """
    Verify a same transaction SSTORE restoration refund credits the
    clearing frame's own reservoir immediately so later state gas in
    that frame is funded. Parametrized to pin the refund as necessary
    and sufficient.
    """
    sstore_state_gas = Op.SSTORE(new_value=1).state_cost(fork)
    create_state_gas = fork.create_state_gas()
    # Premise: the two restoration refunds must be able to cover the
    # CREATE's new-account state gas for the funded path to exist.
    # Drift-proof relationship (vs. hardcoding the constants).
    assert 2 * sstore_state_gas >= create_state_gas

    # Sentinel written only if the CREATE returned (frame did not OOG).
    sentinel_slot = 2
    # refund: clear (1→0, restoration refund). no refund: modify
    # (1→2, no state growth, no refund) — same regular shape.
    cleared_value = 0 if refund_sufficient else 2
    clearing = pre.deploy_contract(
        code=(
            Op.SSTORE(0, cleared_value)
            + Op.SSTORE(1, cleared_value)
            + Op.POP(Op.CREATE(0, 0, 0))
            + Op.SSTORE(sentinel_slot, 1)
            + Op.STOP
        )
    )
    inner: Address = clearing
    for _ in range(delegatecall_depth):
        inner = pre.deploy_contract(
            code=(Op.POP(Op.DELEGATECALL(gas=Op.GAS, address=inner)) + Op.STOP)
        )
    parent = pre.deploy_contract(
        code=(
            Op.SSTORE(0, 1)
            + Op.SSTORE(1, 1)
            + Op.POP(Op.DELEGATECALL(gas=Op.GAS, address=inner))
            + Op.STOP
        )
    )

    # The two parent `0→1` sets spill their state gas into `gas_left`
    # (tx is far below the per-tx cap, so no state-gas reservoir).
    # Budget regular headroom for the call chain plus that spill, then
    # sit mid-window: short of also spill-funding `create_state_gas`,
    # so only a refund-credited reservoir can cover the CREATE.
    regular_headroom = 200_000
    gas_limit = regular_headroom + 2 * sstore_state_gas + create_state_gas // 2

    if refund_sufficient:
        post = {parent: Account(storage={0: 0, 1: 0, sentinel_slot: 1})}
    else:
        # CREATE OOGs in the clearing frame; its writes (the 1→2
        # modifications and the sentinel) revert, leaving the parent's
        # original sets intact.
        post = {parent: Account(storage={0: 1, 1: 1})}

    tx = Transaction(
        to=parent,
        gas_limit=gas_limit,
        sender=pre.fund_eoa(),
    )

    state_test(pre=pre, post=post, tx=tx)

Parametrized Test Cases

This test generates 6 parametrized test cases across 1 fork.