tell: argument splitting/stripping is a bit broken

[dgw]

This code line removes most IRC formatting bytes from the beginning of the message:

sopel/sopel/modules/tell.py

Line 145 in f29c10d

msg = trigger.group(2).lstrip(tellee).lstrip()

It's similar to another issue (#1877) we fixed in choose for 7.1 (#1965). The second .lstrip() with no arguments needs to be replaced with this plugin's own version of _format_safe() from choose.py.

In fact, it wouldn't take much at this point to convince me that Sopel's API should include its own formatting-safe versions of strip(), lstrip(), and rstrip(). Issues like this keep coming up, and stuff like trigger.plain won't help…

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That line also misuses .lstrip() with the tellee's nick. That isn't a huge issue, because it's never going to go past the whitespace, but it could cause other quirks like the fact that punctuation gets through even though the code's intent appears to be treating the tellee as a separate argument that isn't part of the message:

<~dgw> ;tell Creator|TL, comma test
[…]
<&Kaede> [tell] Creator|TL: Monday, July 12, 2021 22:52:44 (IST) <dgw> tell Creator|TL , comma test