Gracefully handle wrong parameter number to WAMP procedures

We should gracefully handle (or allow the app to handle) the situation where a WAMP procedure is called with wrong number of positional arguments:

2019-02-22T15:31:39+0100 [XBRMrktMkr  24056] Traceback (most recent call last):
  File "/home/oberstet/cpy372_7/lib/python3.7/site-packages/autobahn/wamp/websocket.py", line 95, in onMessage
    self._session.onMessage(msg)
  File "/home/oberstet/cpy372_7/lib/python3.7/site-packages/autobahn/wamp/protocol.py", line 939, in onMessage
    on_reply = txaio.as_future(endpoint.fn, *invoke_args, **invoke_kwargs)
  File "/home/oberstet/cpy372_7/lib/python3.7/site-packages/txaio/tx.py", line 428, in as_future
    return ensureDeferred(fun(*args, **kwargs))
TypeError: buy_key() missing 1 required positional argument: 'signature'

2019-02-22T15:31:39+0100 [XBRMrktMkr  24056] dropping connection to peer tcp4:127.0.0.1:8081 with abort=True: I dropped the WebSocket TCP connection: WAMP Internal Error (buy_key() missing 1 required positional argument: 'signature')
2019-02-22T15:31:39+0100 [XBRMrktMkr  24056] session leaving 'wamp.close.transport_lost'
2019-02-22T15:31:39+0100 [XBRMrktMkr  24056] wamp.close.transport_lost: 
2019-02-22T15:31:39+0100 [XBRMrktMkr  24056] >>> Maker session DETACHED from data market (details=CloseDetails(reason=<wamp.close.transport_lost>, message='WAMP transport was lost without closing the session before'))
2019-02-22T15:31:39+0100 [XBRMrktMkr  24056] Stopping factory <autobahn.twisted.websocket.WampWebSocketClientFactory object at 0x7f657992bba8>
2019-02-22T15:31:41+0100 [XBRMrktMkr  24056] connecting once using transport type "websocket" over endpoint "tcp"
2019-02-22T15:31:41+0100 [XBRMrktMkr  24056] Starting factory <autobahn.twisted.websocket.WampWebSocketClientFactory object at 0x7f6575397d68>
2019-02-22T15:31:41+0100 [XBRMrktMkr  24056] >>> Maker session ATTACHED to data market (details=SessionDetails(realm=<realm1>, session=6500367308499916, authid=<HMQY-5EFY-5GEV-LUXM-P3P6-H5VY>, authrole=<xbrmm>, authmethod=anonymous, authprovider=static, authextra={'x_cb_node_id': None, 'x_cb_peer': 'tcp4:127.0.0.1:46350', 'x_cb_pid': 24043}, resumed=None, resumable=None, resume_token=None)) on thread 140074355159168
2019-02-22T15:31:41+0100 [XBRMrktMkr  24056] Registered 8 procedures

[meejah]

I can’t repeat the “second failure” above in the interactive session (neither 3.6.3 or 3.7.3):

Python 3.7.3 (default, May  2 2019, 12:54:42)
Type 'copyright', 'credits' or 'license' for more information
IPython 7.5.0 -- An enhanced Interactive Python. Type '?' for help.

In [1]: import txaio

In [2]: txaio.use_twisted()

In [3]: def foo(a, b):
   ...:     return a + b
   ...: 

In [4]: args = [1, 2]

In [5]: txaio.as_future(foo, *args)
Out[5]: <Deferred at 0x7fd23cef9940 current result: 3>

In [6]: args = [1, 2, 3]

In [7]: txaio.as_future(foo, *args)
Out[7]: <Deferred at 0x7fd23cefdda0 current result: <twisted.python.failure.Failure builtins.TypeError: foo() takes 2 positional arguments but 3 were given>>

In [8]: def moo(a, b, details=None):
   ...:     return a + b
   ...: 

In [9]: txaio.as_future(moo, *args)
Out[9]: <Deferred at 0x7fd23ce9ab70 current result: 3>

I also added an integration test-case for this, which also passes … so I’m closing this, unless there’s another way to repeat the problem?

[meejah]

txaio 18.8.1