test_access_list_warms_storage_slot()

Documentation for tests/amsterdam/eip8038_state_access_gas_cost_increase/test_access_list_gas.py::test_access_list_warms_storage_slot@87aba1a3.

Generate fixtures for these test cases for Amsterdam with:

fill -v tests/amsterdam/eip8038_state_access_gas_cost_increase/test_access_list_gas.py::test_access_list_warms_storage_slot --fork Amsterdam

A storage slot named in the access list is warm on first access.

The first runtime SLOAD/SSTORE of an access-list slot pays the warm cost: WARM_SLOAD for SLOAD; for SSTORE an overwrite of a non-zero original to a new non-zero value pays WARM_SLOAD + STORAGE_WRITE.

Source code in tests/amsterdam/eip8038_state_access_gas_cost_increase/test_access_list_gas.py

@EIPChecklist.GasCostChanges.Test.GasUpdatesMeasurement()
@pytest.mark.parametrize("op", ["SLOAD", "SSTORE"], ids=["sload", "sstore"])
def test_access_list_warms_storage_slot(
    state_test: StateTestFiller,
    env: Environment,
    pre: Alloc,
    fork: Fork,
    op: str,
) -> None:
    """
    A storage slot named in the access list is warm on first access.

    The first runtime ``SLOAD``/``SSTORE`` of an access-list slot pays
    the warm cost: ``WARM_SLOAD`` for ``SLOAD``; for ``SSTORE`` an
    overwrite of a non-zero original to a new non-zero value pays
    ``WARM_SLOAD + STORAGE_WRITE``.
    """
    gas_costs = fork.gas_costs()
    very_low = gas_costs.VERY_LOW
    slot = 0x42

    if op == "SLOAD":
        measured_code: Bytecode = Op.SLOAD(slot)
        # Overhead is just the single PUSH (key); the stored value is the
        # bare warm SLOAD access cost.
        overhead_cost = 1 * very_low
        extra_stack_items = 1
        expected_gas = Op.SLOAD(key_warm=True).gas_cost(fork)
    else:
        measured_code = Op.SSTORE(slot, 2)
        # Overhead is the two PUSHes (key, value); the stored value is
        # the bare warm SSTORE regular cost (overwrite of a non-zero
        # original, no state gas).
        overhead_cost = 2 * very_low
        extra_stack_items = 0
        expected_gas = (
            Op.SSTORE.with_metadata(
                key_warm=True,
                original_value=1,
                current_value=1,
                new_value=2,
            )(slot, 2).regular_cost(fork)
            - 2 * very_low
        )

    code = CodeGasMeasure(
        code=measured_code,
        overhead_cost=overhead_cost,
        extra_stack_items=extra_stack_items,
        sstore_key=1,
    )
    contract = pre.deploy_contract(code=code, storage={slot: 1})

    tx = Transaction(
        to=contract,
        sender=pre.fund_eoa(),
        access_list=[AccessList(address=contract, storage_keys=[slot])],
    )

    # Slot 1 holds the measured warm cost. The data slot ends at its
    # original (SLOAD) or the written value (SSTORE).
    final_slot_value = 1 if op == "SLOAD" else 2
    post = {
        contract: Account(storage={1: expected_gas, slot: final_slot_value})
    }
    state_test(env=env, pre=pre, post=post, tx=tx)

Parametrized Test Cases

This test generates 2 parametrized test cases across 1 fork.