test_access_list_slot_warmth_is_address_scoped()

Documentation for tests/amsterdam/eip8038_state_access_gas_cost_increase/test_access_list_gas.py::test_access_list_slot_warmth_is_address_scoped@622620d8.

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_slot_warmth_is_address_scoped --fork Amsterdam

Access-list slot warmth is scoped to (address, slot).

Slot s of account A is listed in the access list. Reading slot s of A is warm (WARM_SLOAD); reading the same slot number of a different account B is cold (COLD_STORAGE_ACCESS).

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

@EIPChecklist.GasCostChanges.Test.GasUpdatesMeasurement()
def test_access_list_slot_warmth_is_address_scoped(
    state_test: StateTestFiller,
    env: Environment,
    pre: Alloc,
    fork: Fork,
) -> None:
    """
    Access-list slot warmth is scoped to ``(address, slot)``.

    Slot ``s`` of account ``A`` is listed in the access list. Reading
    slot ``s`` of ``A`` is warm (``WARM_SLOAD``); reading the same slot
    number of a different account ``B`` is cold (``COLD_STORAGE_ACCESS``).
    """
    slot = 0x42
    warm_gas = Op.SLOAD(key_warm=True).gas_cost(fork)
    cold_gas = Op.SLOAD(key_warm=False).gas_cost(fork)

    # Both accounts read their own slot ``s`` with the same wrapper, so the
    # overhead that strips the operand PUSH is identical for each.
    measured_read = Op.SLOAD(slot)
    overhead = measured_read.gas_cost(fork) - cold_gas

    # B reads its own slot ``s`` (cold), storing the result in B's slot 1.
    account_b = pre.deploy_contract(
        code=CodeGasMeasure(
            code=measured_read,
            overhead_cost=overhead,
            extra_stack_items=1,
            sstore_key=1,
        ),
        storage={slot: 1},
    )

    # A reads its own slot ``s`` (warm via the access list), then calls B.
    account_a = pre.deploy_contract(
        code=CodeGasMeasure(
            code=measured_read,
            overhead_cost=overhead,
            extra_stack_items=1,
            sstore_key=1,
        )
        + Op.POP(Op.CALL(gas=200_000, address=account_b)),
        storage={slot: 1},
    )

    tx = Transaction(
        to=account_a,
        sender=pre.fund_eoa(),
        # Only A's slot is listed; B's identical slot stays cold.
        access_list=[AccessList(address=account_a, storage_keys=[slot])],
    )

    post = {
        account_a: Account(storage={1: warm_gas, slot: 1}),
        account_b: Account(storage={1: cold_gas, slot: 1}),
    }
    state_test(env=env, pre=pre, post=post, tx=tx)

Parametrized Test Cases

This test generates 1 parametrized test case across 1 fork.