Warning: removes relevant characters from usernames in the channel list

[serious-angel]

Dear Developers,

Thank you for the project.

A warning just to highlight the issue.

Due to Discord channel name formation procedure limitations, it appears only few characters are allowed in the channel name(username based), hence the function format_channel_name.

The line: https://github.com/antigravities/modmail/blob/3f2b9a5b0a4180ec574325d364770bbbbad4ddf4/core/utils.py#L349

# ...
name = new_name = (
    "".join(l for l in name if l not in string.punctuation and l.isprintable()) or "null"
) + f"-{author.discriminator}"
# ...

For example, my username starts with /\ngel#???? which appears ngel-???? in the channel list:

As the result, this may cause different users like ngel#???? or ^ngel#???? and actual me(/\ngel#????) appear in the channel like ngel-???? and ngel-????_1 and confuse a moderator. This may lead to an accidental private data leak.

Best and kind regards ✨

[fourjr]

How do you suggest we tackle this issue?

[serious-angel]

How do you suggest we tackle this issue?

For example, a time(i.e. UTC zoned) of the issue reported and some non-general Unicode characters:

from datetime import datetime

# ...

def format_channel_name(author, guild, exclude_channel=None, force_null=False):
    channel_name = ""

    if force_null:
        channel_name = "null"

    channel_name = channel_name_new = (
        '{dt.year}-{dt.month}-{dt.day}｜{dt.hour:02}ː{dt.minute:02}ː{dt.second:02}'.format(dt = datetime.utcnow())
    ) + f"-{author.discriminator}"
    
    counter = 1
    existed = set(c.name for c in guild.text_channels if c != exclude_channel)

    while channel_name_new in existed:
        channel_name_new = f"{channel_name}｜{counter}" # multiple channels with same name
        counter += 1

    return channel_name_new

A possible result:

As you might notice, the last channel on the above preview is the widest possible(assumed 19 reports at the same second on this particular date) and more than 19 reports at the same second should result in a text overflow, hence trimmed channel name, but what's the probability of such phenomenon? Also, different separators could be used, of course, or even minimal like 181136_03252021 and ＃(U+FF03) character for a counter etc.
Also, Unicode emojis also might fit, for example: 📄, 📜, 📃, 📕, ◽, 🔸, 🔺 etc.

Imagine, what if Discord have used a monospace font for channel names and allowed resizing the panel ^^

Related: https://en.wikipedia.org/wiki/ISO_8601

[serious-angel]

Updated the datetime format

[fourjr]

Suggestion: More ways to customise channel names

For now, you can try out a config option recently added use_user_id_channel_name.

[fourjr]

use_timestamp_channel_name is added in v3.10.0-dev6. Channels are formatted according to YYYY-MM-DD-HHMM using account creation time

[fourjr]

Bot.format_channel_name(bot, author, exclude_channel=None, force_null=False): can now be extended by plugins in v3.10.0-dev7