Check if channel exists before referencing it

[nnsee]

---

name: Check if channel exists before referencing it
about: Avoid referencing #invalid-channel
closes: #335

---

Pull Request Details

Please ensure your PR fulfills the following criteria:

• Have you joined the PythonDiscord Community?
• Were your changes made in a Pipenv environment?
• Does flake8 pass (pipenv run lint)

[Akarys42]

LGMT

[Numerlor]

The constant which provides the channel list should be changed here instead of checking it against the server every time
https://github.com/python-discord/seasonalbot/blob/2679849160f160d8f70c597636798df185873523/bot/constants.py#L141-L146
The invalid channel could also be removed from the Channels constants class

[nnsee]

The constant which provides the channel list should be changed here instead of checking it against the server every time
https://github.com/python-discord/seasonalbot/blob/2679849160f160d8f70c597636798df185873523/bot/constants.py#L141-L146

The invalid channel could also be removed from the Channels constants class

Aye, that was my initial reaction as well, however I opted to also check every time as an extra precaution as it seems like this would prevent the issue from popping up in the future (should the channel list change). I've removed the invalid channel #devtest from both Channels and WHITELISTED_CHANNELS.

[Numerlor]

Not sure what the consensus here is about checking it, because the channels don't really change much.
But if the check remains some sort of logging to notify about invalid channels so they can be removed could also prove to be useful.

[kwzrd]

I think I like the idea of just removing the invalid channel (i.e. ba69450).

... it seems like this would prevent the issue from popping up in the future (should the channel list change) ...

The underlying problem is a misconfigured / outdated constant. The #deleted-channel showing up is a symptom, and dd6063f silences it rather than fixes it. If there exists a problem like this in the code base, it should be observable so that it can be fixed.

[sco1]

The underlying problem is a misconfigured / outdated constant. The #deleted-channel showing up is a symptom, and dd6063f silences it rather than fixes it. If there exists a problem like this in the code base, it should be observable so that it can be fixed.

We've come to an agreement on this, and rather than flagging this randomly when users bounce off of a whitelist, it would be better to solve this issue by validating the channel constants on bot startup & logging a warning if any of them fail to resolve so we can identify & update the problematic constant(s).

[sco1]

Hi @neonSea, any interest in updating the implementation here?

[nnsee]

I will implement functionality to check for invalid channels on startup and warn if there are any. Should I create a separate PR for that, or is this one fine?