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test_jumpdest_in_immediate_at_fork_transition()

Documentation for tests/amsterdam/eip8024_dupn_swapn_exchange/test_fork_transition.py::test_jumpdest_in_immediate_at_fork_transition@26332146.

Generate fixtures for these test cases for Amsterdam with:

fill -v tests/amsterdam/eip8024_dupn_swapn_exchange/test_fork_transition.py::test_jumpdest_in_immediate_at_fork_transition --fork Amsterdam

Test a JUMPDEST inside an EIP-8024 immediate across the transition.

JUMPDEST analysis is unchanged by EIP-8024, so the 0x5b byte in the opcode's would-be immediate is a valid jump destination both before and after the fork. The jump skips the opcode byte itself, so every block stores the marker at its NUMBER-keyed slot.

Source code in tests/amsterdam/eip8024_dupn_swapn_exchange/test_fork_transition.py 
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@EIPChecklist.Opcode.Test.ForkTransition.At()
@EIPChecklist.Opcode.Test.DataPortion.Jump()
@pytest.mark.valid_at_transition_to("EIP8024")
@pytest.mark.parametrize("opcode", [Op.DUPN, Op.SWAPN, Op.EXCHANGE])
def test_jumpdest_in_immediate_at_fork_transition(
    blockchain_test: BlockchainTestFiller,
    pre: Alloc,
    opcode: Op,
) -> None:
    """
    Test a JUMPDEST inside an EIP-8024 immediate across the transition.

    JUMPDEST analysis is unchanged by EIP-8024, so the 0x5b byte in the
    opcode's would-be immediate is a valid jump destination both before
    and after the fork. The jump skips the opcode byte itself, so every
    block stores the marker at its NUMBER-keyed slot.
    """
    sender = pre.fund_eoa()
    marker = 0xD4

    # 00 PUSH1 0x04
    # 02 JUMP
    # 03 <opcode>
    # 04 JUMPDEST (the would-be immediate)
    code = Op.PUSH1(4) + Op.JUMP + opcode[b"\x5b"]
    code += Op.PUSH1(marker) + Op.NUMBER + Op.SSTORE + Op.STOP

    contract = pre.deploy_contract(code)

    blocks = [
        Block(
            timestamp=ts,
            txs=[Transaction(sender=sender, to=contract)],
        )
        for ts in (
            FORK_TIMESTAMP - 1,
            FORK_TIMESTAMP,
            FORK_TIMESTAMP + 1,
        )
    ]

    post = {
        contract: Account(
            storage={
                1: marker,
                2: marker,
                3: marker,
            },
        ),
    }

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

Parametrized Test Cases

This test generates 3 parametrized test cases across 1 fork.