Sync client swallows auth errors

[Gastove]

Description

When given an invalid bot token, the RTM client just... sits there. No error is raised; no output is provided that something is wrong, unless the log level is set to debug, in which case the problem becomes clearly visible:

The server responded with: {'ok': False, 'error': 'invalid_auth'}

What type of issue is this? (place an x in one of the [ ])

• bug
• enhancement (feature request)
• question
• documentation related
• testing related
• discussion

Requirements (place an x in each of the [ ])

• I've read and understood the Contributing guidelines and have done my best effort to follow them.
• I've read and agree to the Code of Conduct.
• I've searched for any related issues and avoided creating a duplicate issue.

---

Bug Report

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Reproducible in:

slackclient version: slackclient==2.2.0

python version: 3.7.4

OS version(s): Fedora 30

Steps to reproduce:

1. Start the RTM client with an invalid token:

rtm_client = slack.RTMClient(token="I am not a token")
rtm_client.start()

Expected result:

I should get a runtime exception of some form, indicating my token is bad.

Actual result:

The client simply runs for as long as I'll let it, with no output of any kind. If I set log level to debug, the API is clearly telling the client about the problem:

The server responded with: {'ok': False, 'error': 'invalid_auth'}

[seratch]

First of all, I'm sorry for no response here.

I just checked this issue. As of version 2.5.0, the behavior seems to be a bit different.

It immediately raises TypeError: 'NoneType' object is not subscriptable. The error information still can be improved. But at least some error happens synchronously.

from slack import RTMClient
try:
    rtm_client = RTMClient(token="I am not a token", run_async=False)
    rtm_client.start()
except Exception as e:
    print(f"*** Immediately got an Exception: {e} ***")
    raise e
finally:
    print("*** finally called ***")

>>> try:
...     rtm_client = RTMClient(token="I am not a token", run_async=False)
...     rtm_client.start()
... except Exception as e:
...     print(f"*** Immediately got an Exception: {e} ***")
...     raise e
... finally:
...     print("*** finally called ***")
... 
*** Immediately got an Exception: 'NoneType' object is not subscriptable ***
*** finally called ***

Traceback (most recent call last):
  File "/path-to-python/site-packages/slack/rtm/client.py", line 329, in _connect_and_read
    url, data = await self._retreive_websocket_info()
  File "/path-to-python/site-packages/slack/rtm/client.py", line 503, in _retreive_websocket_info
    resp = await self._web_client.rtm_connect()
  File "/path-to-python/site-packages/slack/web/base_client.py", line 226, in _send
    return SlackResponse(**{**data, **res}).validate()
  File "/path-to-python/site-packages/slack/web/slack_response.py", line 176, in validate
    raise e.SlackApiError(message=msg, response=self)
slack.errors.SlackApiError: The request to the Slack API failed.
The server responded with: {'ok': False, 'error': 'invalid_auth'}

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "<stdin>", line 6, in <module>
  File "<stdin>", line 3, in <module>
  File "/path-to-python/site-packages/slack/rtm/client.py", line 198, in start
    return self._event_loop.run_until_complete(future)
  File "/path-to-python/asyncio/base_events.py", line 587, in run_until_complete
    return future.result()
  File "/path-to-python/site-packages/slack/rtm/client.py", line 356, in _connect_and_read
    await self._wait_exponentially(exception)
  File "/path-to-python/site-packages/slack/rtm/client.py", line 523, in _wait_exponentially
    wait_time = exception.response["headers"]["Retry-After"]
TypeError: 'NoneType' object is not subscriptable

[seratch]

Let me close this issue now as #662 resolved it.

[seratch]

👋 slackclient 2.6.0rc1 is out. The pre-release version contains fixes for your issue described here.
https://pypi.org/project/slackclient/2.6.0rc1/

One week later from now, we'll be releasing version 2.6.0 to PyPI.

If you have a chance, could you try the release candidate version out and let us know your feedback? Thank you very much for being patient with this issue.