test_swapn_jump_to_immediate_byte_0x5b_succeeds()

Documentation for tests/amsterdam/eip8024_dupn_swapn_exchange/test_swapn.py::test_swapn_jump_to_immediate_byte_0x5b_succeeds@c74f1a67.

Generate fixtures for these test cases for Amsterdam with:

fill -v tests/amsterdam/eip8024_dupn_swapn_exchange/test_swapn.py::test_swapn_jump_to_immediate_byte_0x5b_succeeds --fork Amsterdam

Test that jumping to 0x5b after SWAPN succeeds (backward compat).

Bytecode: PUSH1(4) JUMP SWAPN[0x5b] Hex: 6004 56 e7 5b Position 4 contains 0x5b which is an INVALID immediate for SWAPN. Per EIP-8024, 0x5b is preserved as valid JUMPDEST for compatibility. The SWAPN instruction is never executed due to the jump.

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

def test_swapn_jump_to_immediate_byte_0x5b_succeeds(
    pre: Alloc,
    state_test: StateTestFiller,
) -> None:
    """
    Test that jumping to 0x5b after SWAPN succeeds (backward compat).

    Bytecode: PUSH1(4) JUMP SWAPN[0x5b]
    Hex: 6004 56 e7 5b
    Position 4 contains 0x5b which is an INVALID immediate for SWAPN.
    Per EIP-8024, 0x5b is preserved as valid JUMPDEST for compatibility.
    The SWAPN instruction is never executed due to the jump.
    """
    sender = pre.fund_eoa()

    # Build code that jumps to 0x5b after SWAPN opcode
    code = Bytecode()
    code += Op.PUSH1(4)  # Push jump target (position 4)
    code += Op.JUMP  # Jump to position 4
    # Pass as bytes (raw immediate byte for testing)
    code += Op.SWAPN[b"\x5b"]  # Position 3-4: SWAPN + 0x5b (invalid)

    # This SHOULD execute because 0x5b is a valid JUMPDEST
    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 succeeds - 0x5b is preserved as valid JUMPDEST
    post = {contract_address: Account(storage={0: 0x42})}

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

Parametrized Test Cases

This test generates 1 parametrized test case across 1 fork.