Pre-check bans before applying filters that result in a ban

bot/exts/filtering/_settings_types/actions/infraction_and_notification.py

@@ -15,6 +15,7 @@
 from bot.exts.filtering._filter_context import FilterContext
 from bot.exts.filtering._settings_types.settings_entry import ActionEntry
 from bot.exts.filtering._utils import CustomIOField, FakeContext
+from bot.exts.moderation.infraction import _utils as infraction_utils
 from bot.utils.time import humanize_delta, parse_duration_string, relativedelta_to_timedelta
 
 log = get_logger(__name__)
@@ -87,14 +88,14 @@ async def invoke(
         alerts_channel: discord.TextChannel,
         duration: InfractionDuration,
         reason: str
-    ) -> None:
+    ) -> str | None:
         """Invokes the command matching the infraction name."""
         command_name = self.name.lower()
         command = bot_module.instance.get_command(command_name)
         if not command:
             await alerts_channel.send(f":warning: Could not apply {command_name} to {user.mention}: command not found.")
             log.warning(f":warning: Could not apply {command_name} to {user.mention}: command not found.")
-            return
+            return None
 
         if isinstance(user, discord.User):  # For example because a message was sent in a DM.
             member = await get_or_fetch_member(channel.guild, user.id)
@@ -105,14 +106,20 @@ async def invoke(
                     f"The user {user} were set to receive an automatic {command_name}, "
                     "but they were not found in the guild."
                 )
-                return
+                return None
 
         ctx = FakeContext(message, channel, command)
+        if self is Infraction.BAN:
+            active_infraction = await infraction_utils.get_active_infraction(ctx, user, "ban", send_msg=False)
+            if active_infraction:
+                return "already banned"
+
         if self.name in ("KICK", "WARNING", "WATCH", "NOTE"):
             await command(ctx, user, reason=reason or None)
         else:
             duration = arrow.utcnow().datetime + duration.value if duration.value else None
             await command(ctx, user, duration, reason=reason or None)
+        return passive_form[self.name]
 
 
 class InfractionAndNotification(ActionEntry):
@@ -203,10 +210,11 @@ async def action(self, ctx: FilterContext) -> None:
                 log.error(f"Unable to apply infraction as the context channel {channel} can't be found.")
                 return
 
-            await self.infraction_type.invoke(
+            infraction_action = await self.infraction_type.invoke(
                 ctx.author, ctx.message, channel, alerts_channel, self.infraction_duration, self.infraction_reason
             )
-            ctx.action_descriptions.append(passive_form[self.infraction_type.name])
+            if infraction_action:
+                ctx.action_descriptions.append(infraction_action)
 
     def union(self, other: Self) -> Self:
         """

bot/exts/filtering/_ui/ui.py

@@ -616,7 +616,7 @@ class AlertView(discord.ui.View):
     def __init__(self, ctx: FilterContext, triggered_filters: dict[FilterList, list[str]] | None = None):
         super().__init__(timeout=ALERT_VIEW_TIMEOUT)
         self.ctx = ctx
-        if "banned" in self.ctx.action_descriptions:
+        if {"banned", "already banned"} & set(self.ctx.action_descriptions):
             # If the user has already been banned, do not attempt to add phishing button since the URL or guild invite
             # is probably already added as a filter
             return

tests/bot/exts/filtering/test_settings_entries.py

@@ -1,5 +1,5 @@
 import unittest
-from unittest.mock import patch
+from unittest.mock import AsyncMock, patch
 
 from bot.constants import Roles
 from bot.exts.filtering._filter_context import Event, FilterContext
@@ -238,3 +238,66 @@ def test_clean_ban_mentions_removes_moderator_and_broad_mentions(self, resolve_m
         cleaned = _clean_ban_mentions(mentions)
 
         self.assertSetEqual(cleaned, {"other-role", "12345"})
+
+
+class InfractionActionTests(unittest.IsolatedAsyncioTestCase):
+    """Tests for infraction action behavior in filtering."""
+
+    @patch("bot.exts.filtering._settings_types.actions.infraction_and_notification.infraction_utils.get_active_infraction")
+    @patch("bot.exts.filtering._settings_types.actions.infraction_and_notification.bot_module.instance")
+    async def test_ban_action_marks_already_banned_when_active_ban_exists(self, bot_instance, get_active_infraction):
+        """A pre-existing active ban should be reported as already banned without invoking the ban command."""
+        member = MockMember(id=123)
+        channel = MockTextChannel(id=345)
+        alerts_channel = MockTextChannel(id=999)
+        message = MockMessage(author=member, channel=channel)
+        ctx = FilterContext(Event.MESSAGE, member, channel, "", message)
+
+        ban_command = AsyncMock()
+        bot_instance.get_command.return_value = ban_command
+        bot_instance.get_channel.return_value = alerts_channel
+        get_active_infraction.return_value = {"id": 42, "type": "ban"}
+
+        action = InfractionAndNotification(
+            infraction_type="BAN",
+            infraction_reason="reason",
+            infraction_duration=InfractionDuration(0),
+            dm_content="",
+            dm_embed="",
+            infraction_channel=0,
+        )
+
+        await action.action(ctx)
+
+        self.assertEqual(ctx.action_descriptions, ["already banned"])
+        ban_command.assert_not_awaited()
+        get_active_infraction.assert_awaited_once()
+
+    @patch("bot.exts.filtering._settings_types.actions.infraction_and_notification.infraction_utils.get_active_infraction")
+    @patch("bot.exts.filtering._settings_types.actions.infraction_and_notification.bot_module.instance")
+    async def test_ban_action_marks_banned_when_no_active_ban(self, bot_instance, get_active_infraction):
+        """A successful ban path should preserve the existing banned action description."""
+        member = MockMember(id=123)
+        channel = MockTextChannel(id=345)
+        alerts_channel = MockTextChannel(id=999)
+        message = MockMessage(author=member, channel=channel)
+        ctx = FilterContext(Event.MESSAGE, member, channel, "", message)
+
+        ban_command = AsyncMock()
+        bot_instance.get_command.return_value = ban_command
+        bot_instance.get_channel.return_value = alerts_channel
+        get_active_infraction.return_value = None
+
+        action = InfractionAndNotification(
+            infraction_type="BAN",
+            infraction_reason="reason",
+            infraction_duration=InfractionDuration(0),
+            dm_content="",
+            dm_embed="",
+            infraction_channel=0,
+        )
+
+        await action.action(ctx)
+
+        self.assertEqual(ctx.action_descriptions, ["banned"])
+        ban_command.assert_awaited_once()