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test_top_frame_state_charge_empty_precompile()

Documentation for tests/amsterdam/eip2780_reduce_intrinsic_tx_gas/test_top_frame_charges.py::test_top_frame_state_charge_empty_precompile@c74f1a67.

Generate fixtures for these test cases for Amsterdam with:

fill -v tests/amsterdam/eip2780_reduce_intrinsic_tx_gas/test_top_frame_charges.py::test_top_frame_state_charge_empty_precompile --fork Amsterdam

An empty precompile recipient is still empty per EIP-161, so a value-moving transaction to it must pay the top-frame NEW_ACCOUNT state-gas charge.

The gas limit is one short of covering that state charge. Without the charge, the transaction would reach the identity precompile and transfer value, which makes this a direct regression test for a precompile carve-out.

Source code in tests/amsterdam/eip2780_reduce_intrinsic_tx_gas/test_top_frame_charges.py 
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def test_top_frame_state_charge_empty_precompile(
    fork: Fork,
    pre: Alloc,
    state_test: StateTestFiller,
) -> None:
    """
    An empty precompile recipient is still empty per EIP-161, so a
    value-moving transaction to it must pay the top-frame
    ``NEW_ACCOUNT`` state-gas charge.

    The gas limit is one short of covering that state charge. Without
    the charge, the transaction would reach the identity precompile and
    transfer value, which makes this a direct regression test for a
    precompile carve-out.
    """
    sender_initial_balance = 10**18
    sender = pre.fund_eoa(sender_initial_balance)
    identity_precompile = Address(0x04)

    value = 1
    intrinsic_gas = fork.transaction_intrinsic_cost_calculator()(
        sends_value=True,
        recipient_type=RecipientType.PRECOMPILE,
        return_cost_deducted_prior_execution=True,
    )
    top_frame_state_gas = fork.transaction_top_frame_state_gas(
        sends_value=True,
        recipient_type=RecipientType.EMPTY_ACCOUNT,
    )
    assert top_frame_state_gas > 0, (
        "top-frame state gas must be non-zero for empty recipients"
    )

    gas_price = 1_000_000_000
    gas_limit = intrinsic_gas + top_frame_state_gas - 1
    tx = Transaction(
        sender=sender,
        to=identity_precompile,
        value=value,
        gas_limit=gas_limit,
        gas_price=gas_price,
    )

    post = {
        sender: Account(
            nonce=1,
            balance=sender_initial_balance - gas_limit * gas_price,
        ),
        identity_precompile: None,
    }

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

Parametrized Test Cases

This test generates 1 parametrized test case across 1 fork.