test_vector_exchange_valid_0x50()

Documentation for tests/amsterdam/eip8024_dupn_swapn_exchange/test_eip_vectors.py::test_vector_exchange_valid_0x50@9c2813ee.

Generate fixtures for these test cases for Amsterdam with:

fill -v tests/amsterdam/eip8024_dupn_swapn_exchange/test_eip_vectors.py::test_vector_exchange_valid_0x50 --fork Amsterdam

Test vector: e850 [EXCHANGE 14 16].

EXCHANGE with immediate 0x50 (80 decimal) is valid. decode_pair(0x50) = (14, 16), swaps positions 15 and 17.

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

def test_vector_exchange_valid_0x50(
    pre: Alloc,
    state_test: StateTestFiller,
) -> None:
    """
    Test vector: e850 [EXCHANGE 14 16].

    EXCHANGE with immediate 0x50 (80 decimal) is valid.
    decode_pair(0x50) = (14, 16), swaps positions 15 and 17.
    """
    sender = pre.fund_eoa()

    # Build stack with 17 items, with known values at positions 15 and 17
    code = Bytecode()
    for i in range(17):
        stack_pos = 17 - i  # Position from top (1-indexed)
        if stack_pos == 15:
            code += Op.PUSH2(0xAAAA)
        elif stack_pos == 17:
            code += Op.PUSH2(0xBBBB)
        else:
            code += Op.PUSH2(0x1000 + i)

    # EXCHANGE with immediate 0x50 - swaps positions 15 and 17
    code += Op.EXCHANGE[b"\x50"]

    # Store swapped positions to verify
    # Pop to position 15 (pop 14 items)
    for _ in range(14):
        code += Op.POP
    code += Op.PUSH1(0) + Op.SSTORE  # Position 15 (was 0xBBBB)
    code += Op.POP  # Skip position 16
    code += Op.PUSH1(1) + Op.SSTORE  # Position 17 (was 0xAAAA)
    code += Op.STOP

    contract_address = pre.deploy_contract(code=code)
    tx = Transaction(to=contract_address, sender=sender, gas_limit=1_000_000)

    post = {
        contract_address: Account(
            storage={
                0: 0xBBBB,  # Position 15 now has value from 17
                1: 0xAAAA,  # Position 17 now has value from 15
            }
        )
    }

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

Parametrized Test Cases

This test generates 1 parametrized test case across 1 fork.