test_reservoir_returned_on_revert()

Documentation for tests/amsterdam/eip8037_state_creation_gas_cost_increase/test_state_gas_call.py::test_reservoir_returned_on_revert@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_reservoir_returned_on_revert --fork Amsterdam

Test state gas reservoir is returned to parent on child revert.

The child draws the whole reservoir for an SSTORE then reverts, restoring it. Repeating that leaves the parent with only one SSTORE's execution cost, so its own SSTORE has nothing to spill from and lands only if the restores went back to the reservoir.

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

@pytest.mark.valid_from("EIP8037")
def test_reservoir_returned_on_revert(
    state_test: StateTestFiller,
    pre: Alloc,
    fork: Fork,
) -> None:
    """
    Test state gas reservoir is returned to parent on child revert.

    The child draws the whole reservoir for an SSTORE then reverts,
    restoring it. Repeating that leaves the parent with only one
    SSTORE's execution cost, so its own SSTORE has nothing to spill
    from and lands only if the restores went back to the reservoir.
    """
    sstore_state_gas = Op.SSTORE(new_value=1).state_cost(fork)

    child_code = Op.SSTORE(0, 1) + Op.REVERT(0, 0)
    child = pre.deploy_contract(code=child_code)

    parent_storage = Storage()
    final_sstore = Op.SSTORE(parent_storage.store_next(1), 1)

    child_gas = child_code.execution_cost(fork)
    parent_code = (
        WhileGas(
            body=Op.POP(
                Op.CALL(
                    gas=child_gas,
                    address=child,
                    # gas accounting
                    address_warm=True,
                    inner_call_cost=child_gas,
                )
            ),
            fork=fork,
            extra_gas=final_sstore.execution_cost(fork),
        )
        + final_sstore
    )
    parent = pre.deploy_contract(code=parent_code)

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

    post = {parent: Account(storage=parent_storage)}
    state_test(pre=pre, post=post, tx=tx)

Parametrized Test Cases

This test generates 1 parametrized test case across 1 fork.