Add consecutive newline detection to antispam

Add consecutive newline threshold to configuration

Send newline antispam violations to logs API rather than the modlog
embed in order to keep excessive logs out of the log channel while
still retaining context on what was filtered.

3 files changed, 25 insertions, 5 deletions

diff --git a/bot/cogs/antispam.py b/bot/cogs/antispam.py
index 800700a50..0d1c7c1e9 100644
--- a/bot/cogs/antispam.py
+++ b/bot/cogs/antispam.py
@@ -97,13 +97,13 @@ class AntiSpam:
                     # Fire it off as a background task to ensure
                     # that the sleep doesn't block further tasks
                     self.bot.loop.create_task(
-                        self.punish(message, member, full_reason, relevant_messages)
+                        self.punish(message, member, full_reason, relevant_messages, rule_name)
                     )
 
                 await self.maybe_delete_messages(message.channel, relevant_messages)
                 break
 
-    async def punish(self, msg: Message, member: Member, reason: str, messages: List[Message]):
+    async def punish(self, msg: Message, member: Member, reason: str, messages: List[Message], rule_name: str):
         # Sanity check to ensure we're not lagging behind
         if self.muted_role not in member.roles:
             remove_role_after = AntiSpamConfig.punishment['remove_after']
@@ -114,8 +114,8 @@ class AntiSpam:
                 f"**Reason:** {reason}\n"
             )
 
-            # For multiple messages, use the logs API
-            if len(messages) > 1:
+            # For multiple messages or those with excessive newlines, use the logs API
+            if len(messages) > 1 or rule_name == 'newlines':
                 url = await self.mod_log.upload_log(messages)
                 mod_alert_message += f"A complete log of the offending messages can be found [here]({url})"
             else:
diff --git a/bot/rules/newlines.py b/bot/rules/newlines.py
index a6a1a52d0..e7c665750 100644
--- a/bot/rules/newlines.py
+++ b/bot/rules/newlines.py
@@ -1,5 +1,6 @@
 """Detects total newlines exceeding the set limit sent by a single user."""
 
+import re
 from typing import Dict, Iterable, List, Optional, Tuple
 
 from discord import Member, Message
@@ -17,12 +18,30 @@ async def apply(
         if msg.author == last_message.author
     )
 
-    total_recent_newlines = sum(msg.content.count('\n') for msg in relevant_messages)
+    # Identify groups of newline characters and get group & total counts
+    exp = r"(\n+)"
+    newline_counts = [len(group) for group in re.findall(exp, instr)]
+    total_recent_newlines = sum(newline_counts)
 
+    # Get maximum newline group size
+    if newline_counts:
+        max_newline_group = max(newline_counts)
+    else:
+        # If no newlines are found, newline_counts will be an empty list, which will error out max()
+        max_newline_group = 0
+
+    # Check first for total newlines, if this passes then check for large groupings
     if total_recent_newlines > config['max']:
         return (
             f"sent {total_recent_newlines} newlines in {config['interval']}s",
             (last_message.author,),
             relevant_messages
         )
+    elif max_newline_group > config['max_consecutive']:
+        return (
+            f"sent {max_newline_group} consecutive newlines in {config['interval']}s",
+            (last_message.author,),
+            relevant_messages
+        )
+
     return None
diff --git a/config-default.yml b/config-default.yml
index 5938ae533..14f9dabc5 100644
--- a/config-default.yml
+++ b/config-default.yml
@@ -316,6 +316,7 @@ anti_spam:
         newlines:
             interval: 10
             max: 100
+            max_consecutive: 10
 
         role_mentions:
             interval: 10