test_block_gas_used_at_fork_transition()

Documentation for tests/amsterdam/eip7778_block_gas_accounting_without_refunds/test_fork_transition.py::test_block_gas_used_at_fork_transition@622620d8.

Generate fixtures for these test cases for Amsterdam with:

fill -v tests/amsterdam/eip7778_block_gas_accounting_without_refunds/test_fork_transition.py::test_block_gas_used_at_fork_transition --fork Amsterdam

Pin the gas a block reports on each side of the activation boundary.

The same refunding transaction shape is sent in a pre-fork and a post-fork block, each with its own sender so the receipt and balance pins stay per-fork. The header reports post-refund gas before the fork and pre-refund gas after it, while the sender is charged the post-refund amount on both sides.

Source code in tests/amsterdam/eip7778_block_gas_accounting_without_refunds/test_fork_transition.py

@EIPChecklist.BlockLevelConstraint.Test.ForkTransition.AcceptedBeforeFork()
@EIPChecklist.BlockLevelConstraint.Test.ForkTransition.AcceptedAfterFork()
def test_block_gas_used_at_fork_transition(
    blockchain_test: BlockchainTestFiller,
    pre: Alloc,
    fork: TransitionFork,
) -> None:
    """
    Pin the gas a block reports on each side of the activation boundary.

    The same refunding transaction shape is sent in a pre-fork and a
    post-fork block, each with its own sender so the receipt and balance
    pins stay per-fork. The header reports post-refund gas before the
    fork and pre-refund gas after it, while the sender is charged the
    post-refund amount on both sides.
    """
    blocks = []
    post: Dict[Address, Account | None] = {}

    for timestamp in (PRE_FORK_TIMESTAMP, POST_FORK_TIMESTAMP):
        sub_fork = fork.fork_at(timestamp=timestamp)

        refund_tx = RefundTransaction.build(
            fork=sub_fork,
            sender=pre.fund_eoa(INITIAL_FUND),
            refund_types={RefundTypes.STORAGE_CLEAR},
            refunds_count=REFUNDS_COUNT,
        )
        refund_tx.set_pre(pre)

        receipt_gas_used = refund_tx.expected_receipt.gas_used
        assert receipt_gas_used is not None
        assert refund_tx.block_execution() > receipt_gas_used, (
            "Parametrization must produce a refund; without one pre- and "
            "post-refund accounting agree"
        )

        # EIP-7778 switches the block from the post-refund charge to the
        # pre-refund one; the sender pays the post-refund amount either
        # way.
        expected_gas_used: int
        if timestamp < POST_FORK_TIMESTAMP:
            expected_gas_used = receipt_gas_used
        else:
            expected_gas_used = refund_tx.block_execution()

        blocks.append(
            Block(
                timestamp=timestamp,
                txs=[refund_tx],
                expected_gas_used=expected_gas_used,
            )
        )
        post.update(dict(refund_tx.post(pre).items()))

    blockchain_test(pre=pre, blocks=blocks, post=post)

Parametrized Test Cases

This test generates 1 parametrized test case across 1 fork.