Specific type check behavior

[oberstet]

consider this registered procedure:

    @wamp.register('network.xbr.console.get_member_logins', check_types=True)
    def get_member_logins(self, member_oid: bytes, details: Optional[CallDetails] = None) -> list:

when this procedure is called with 2 (!) arguments, the resulting traceback is:

2020-02-20T21:59:49+0100 [Router      19483] XbrNetworkApi.onUserError(): "AttributeError: __name__"
Traceback (most recent call last):
  File "/home/oberstet/scm/crossbario/autobahn-python/autobahn/wamp/protocol.py", line 1020, in onMessage
    on_reply = txaio.as_future(endpoint.fn, *invoke_args, **invoke_kwargs)
  File "/home/oberstet/scm/crossbario/txaio/txaio/tx.py", line 365, in as_future
    return ensureDeferred(fun(*args, **kwargs))
  File "/home/oberstet/cpy381_3/lib/python3.8/site-packages/twisted/internet/defer.py", line 911, in ensureDeferred
    return _cancellableInlineCallbacks(coro)
  File "/home/oberstet/cpy381_3/lib/python3.8/site-packages/twisted/internet/defer.py", line 1529, in _cancellableInlineCallbacks
    _inlineCallbacks(None, g, status)
--- <exception caught here> ---
  File "/home/oberstet/cpy381_3/lib/python3.8/site-packages/twisted/internet/defer.py", line 1418, in _inlineCallbacks
    result = g.send(result)
  File "/home/oberstet/scm/crossbario/autobahn-python/autobahn/wamp/protocol.py", line 508, in _type_check
    "'{}' required={} got={}".format(name, kind.__name__, type(arguments[name]).__name__))
  File "/home/oberstet/cpy381/lib/python3.8/typing.py", line 757, in __getattr__
    raise AttributeError(attr)
builtins.AttributeError: __name__

this is super-obscure and unexpected ..

when turning off type checks, it will run into the assert within the procedure body:

2020-02-20T22:02:07+0100 Traceback (most recent call last):
  File "/home/oberstet/cpy381_3/lib/python3.8/site-packages/twisted/internet/defer.py", line 654, in _runCallbacks
    current.result = callback(current.result, *args, **kw)
  File "/home/oberstet/cpy381_3/lib/python3.8/site-packages/twisted/internet/defer.py", line 1475, in gotResult
    _inlineCallbacks(r, g, status)
  File "/home/oberstet/cpy381_3/lib/python3.8/site-packages/twisted/internet/defer.py", line 1416, in _inlineCallbacks
    result = result.throwExceptionIntoGenerator(g)
  File "/home/oberstet/cpy381_3/lib/python3.8/site-packages/twisted/python/failure.py", line 512, in throwExceptionIntoGenerator
    return g.throw(self.type, self.value, self.tb)
--- <exception caught here> ---
  File "./backend/test/test_api_login.py", line 72, in onJoin
    await self._onJoin(details)
  File "./backend/test/test_api_login.py", line 149, in _onJoin
    pubkeys = await self.call('network.xbr.console.get_member_logins', member_oid, vaction_code)
autobahn.wamp.exception.ApplicationError: ApplicationError(error=<wamp.error.runtime_error>, args=['details must be `autobahn.wamp.types.CallDetails`, but was `JEJX-5S3F-XWMF`'], kwargs={}, enc_algo=None, callee=None, callee_authid=None, callee_authrole=None, forward_for=None)

[oberstet]

so on the user side, I was doing (wrong):

pubkeys = await self.call('network.xbr.console.get_member_logins', member_oid, vaction_code)

whereas I should have done (correct):

pubkeys = await self.call('network.xbr.console.get_member_logins', member_oid)

this is obviously quite a bad trap for beginner (I know enough details so I was able to find out the real issue quickly .. but without knowledge of inner mechanics, could be annoying ..)