Tighter mention filtering in auto-ban mod-alerts (#3530)

* Only remove moderators/broad pings from auto-ban mod-alerts

* Add new test to validate mention removal

Author: jb3

bot/exts/filtering/filtering.py

@@ -47,7 +47,7 @@
     build_mod_alert,
     format_response_error,
 )
-from bot.exts.filtering._utils import past_tense, repr_equals, starting_value, to_serializable
+from bot.exts.filtering._utils import past_tense, repr_equals, resolve_mention, starting_value, to_serializable
 from bot.exts.moderation.infraction.infractions import COMP_BAN_DURATION, COMP_BAN_REASON
 from bot.exts.utils.snekbox._io import FileAttachment
 from bot.log import get_logger
@@ -66,6 +66,21 @@
 WEEKLY_REPORT_ISO_DAY = 3  # 1=Monday, 7=Sunday
 
 
+def _clean_ban_mentions(mentions: set[str]) -> set[str]:
+    """Remove broad pings and moderators role pings from ban alerts."""
+    blocked_mentions = {f"<@&{Roles.moderators}>", "@here", "@everyone"}
+    cleaned_mentions = set()
+
+    for mention in mentions:
+        if mention.casefold() == "moderators":
+            continue
+        if resolve_mention(mention) in blocked_mentions:
+            continue
+        cleaned_mentions.add(mention)
+
+    return cleaned_mentions
+
+
 async def _extract_text_file_content(att: discord.Attachment) -> str:
     """Extract up to the first 30 lines or first 2000 characters (whichever is shorter) of an attachment."""
     file_encoding = re.search(r"charset=(\S+)", att.content_type).group(1)
@@ -981,7 +996,9 @@ async def _resolve_action(
             # If the action is a ban, mods don't want to be pinged.
             if infr_action := result_actions.get("infraction_and_notification"):
                 if infr_action.infraction_type == Infraction.BAN:
-                    result_actions.pop("mentions", None)
+                    if mentions := result_actions.get("mentions"):
+                        mentions.guild_pings = _clean_ban_mentions(mentions.guild_pings)
+                        mentions.dm_pings = _clean_ban_mentions(mentions.dm_pings)
         return result_actions, messages, triggers
 
     async def _send_alert(self, ctx: FilterContext, triggered_filters: dict[FilterList, Iterable[str]]) -> None:

tests/bot/exts/filtering/test_settings_entries.py

@@ -1,5 +1,7 @@
 import unittest
+from unittest.mock import patch
 
+from bot.constants import Roles
 from bot.exts.filtering._filter_context import Event, FilterContext
 from bot.exts.filtering._settings_types.actions.infraction_and_notification import (
     Infraction,
@@ -9,6 +11,7 @@
 from bot.exts.filtering._settings_types.validations.bypass_roles import RoleBypass
 from bot.exts.filtering._settings_types.validations.channel_scope import ChannelScope
 from bot.exts.filtering._settings_types.validations.filter_dm import FilterDM
+from bot.exts.filtering.filtering import _clean_ban_mentions
 from tests.helpers import MockCategoryChannel, MockDMChannel, MockMember, MockMessage, MockRole, MockTextChannel
 
 
@@ -218,3 +221,20 @@ def test_infraction_merge_of_different_infraction_types(self):
                 "infraction_channel": 0
             }
         )
+
+    @patch("bot.exts.filtering.filtering.resolve_mention")
+    def test_clean_ban_mentions_removes_moderator_and_broad_mentions(self, resolve_mention_mock):
+        """Ban-alert mention cleanup should remove moderator, here, and everyone pings."""
+        resolve_mention_mock.side_effect = lambda mention: {
+            "here": "@here",
+            "everyone": "@everyone",
+            "Moderators": f"<@&{Roles.moderators}>",
+            str(Roles.moderators): f"<@&{Roles.moderators}>",
+            "other-role": "<@&123>",
+        }.get(mention, mention)
+
+        mentions = {"here", "everyone", "Moderators", str(Roles.moderators), "other-role", "12345"}
+
+        cleaned = _clean_ban_mentions(mentions)
+
+        self.assertSetEqual(cleaned, {"other-role", "12345"})