test_swapn_invalid_immediate_aborts()

Documentation for tests/amsterdam/eip8024_dupn_swapn_exchange/test_swapn.py::test_swapn_invalid_immediate_aborts@c74f1a67.

Generate fixtures for these test cases for Amsterdam with:

fill -v tests/amsterdam/eip8024_dupn_swapn_exchange/test_swapn.py::test_swapn_invalid_immediate_aborts --fork Amsterdam

Test SWAPN with invalid immediate values (90 < x < 128) aborts.

Per EIP-8024, immediate values in range [91, 127] (0x5b-0x7f) are invalid because they correspond to JUMPDEST (0x5b) and PUSH opcodes (0x60-0x7f). Attempting to execute SWAPN with these immediates should abort.

Source code in tests/amsterdam/eip8024_dupn_swapn_exchange/test_swapn.py

@pytest.mark.parametrize(
    "invalid_immediate",
    list(range(91, 128)),  # 0x5b to 0x7f (JUMPDEST and PUSH opcodes)
    ids=lambda x: f"swapn_invalid_imm_0x{x:02x}",
)
def test_swapn_invalid_immediate_aborts(
    invalid_immediate: int,
    pre: Alloc,
    state_test: StateTestFiller,
) -> None:
    """
    Test SWAPN with invalid immediate values (90 < x < 128) aborts.

    Per EIP-8024, immediate values in range [91, 127] (0x5b-0x7f) are
    invalid because they correspond to JUMPDEST (0x5b) and PUSH opcodes
    (0x60-0x7f). Attempting to execute SWAPN with these immediates should
    abort.
    """
    sender = pre.fund_eoa()

    # Build a stack tall enough for any valid immediate (max decoded index
    # is 235, SWAPN needs index + 1 items) so the abort is caused by the
    # invalid immediate, never an underflow.
    code = Bytecode()
    for i in range(Spec.MAX_STACK_INDEX + 1):
        code += Op.PUSH1(i % 256)

    # Attempt SWAPN with invalid immediate - should abort.
    # Pass as bytes (raw immediate byte for testing invalid ranges).
    code += Op.SWAPN[invalid_immediate.to_bytes(1, "big")]

    # This should never execute.
    code += Op.PUSH1(0x42) + Op.PUSH1(0) + Op.SSTORE
    code += Op.STOP

    contract_address = pre.deploy_contract(code=code)

    tx = Transaction(to=contract_address, sender=sender)

    # Transaction should fail - invalid immediate causes abort.
    post = {contract_address: Account(storage={})}

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

Parametrized Test Cases

This test generates 37 parametrized test cases across 1 fork.