DMs: improve bot mention stripping

...to handle fully qualified fediverse handles, eg @[email protected]

for #1474

dms.py

@@ -99,11 +99,6 @@ def receive(*, from_user, obj):
 
     soup = util.parse_html(inner_obj.get('content', ''))
 
-    # remove @-mention of bot
-    if first_link := soup.a:
-        if first_link.get_text().strip().lstrip('@') in DOMAINS + ids.BOT_ACTOR_AP_IDS:
-            first_link.extract()
-
     content = soup.get_text().strip().lower()
     if not content:
         return r'¯\_(ツ)_/¯', 204
@@ -114,9 +109,16 @@ def reply(text, type=None):
         return 'OK', 200
 
     # parse and handle message
-    split = content.split(maxsplit=1)
-    cmd = split[0].lstrip('/')
-    arg = split[1] if len(split) > 1 else None
+    tokens = content.split()
+
+    # remove @-mention of bot, if any
+    bot_handles = (DOMAINS + ids.BOT_ACTOR_AP_IDS
+                   + tuple(h.lstrip('@') for h in ids.BOT_ACTOR_AP_HANDLES))
+    if tokens[0].lstrip('@') in bot_handles:
+        tokens = tokens[1:]
+
+    cmd = tokens[0].lstrip('/')
+    arg = tokens[1] if len(tokens) > 1 else None
 
     extra = ''
     if to_proto.LABEL == 'atproto':

ids.py

@@ -41,6 +41,7 @@
 # can't use translate_user_id because Web.owns_id checks valid_domain, which
 # doesn't allow our protocol subdomains
 BOT_ACTOR_AP_IDS = tuple(f'https://{domain}/{domain}' for domain in PROTOCOL_DOMAINS)
+BOT_ACTOR_AP_HANDLES = tuple(f'@{domain}@{domain}' for domain in PROTOCOL_DOMAINS)
 
 
 def validate(id, from_, to):

tests/test_dms.py

@@ -54,7 +54,7 @@ def assert_sent(self, from_cls, tos, type, text, in_reply_to=None):
             tos = [tos]
 
         from_id = f'{from_cls.ABBREV}.brid.gy'
-        for expected, (target, activity) in zip(tos, tos[0].sent):
+        for expected, (target, activity) in zip(tos, tos[-1].sent):
             id = expected.key.id()
             self.assertEqual(f'{id}:target', target)
             content = activity['object'].pop('content')
@@ -396,6 +396,26 @@ def test_receive_help(self):
         self.assert_replied(OtherFake, alice, '?', "<p>Hi! I'm a friendly bot")
         self.assertEqual({}, OtherFake.usernames)
 
+    def test_receive_help_strip_mention_of_bot(self):
+        self.make_user(id='other.brid.gy', cls=Web)
+        alice = self.make_user(id='efake:alice', cls=ExplicitFake,
+                               enabled_protocols=['other'], obj_as1={'x': 'y'})
+
+        for content in (
+                '@other.brid.gy /help',
+                '[email protected] /help',
+                '@[email protected] /help',
+                'https://other.brid.gy/other.brid.gy /help',
+        ):
+            ExplicitFake.sent = []
+            with self.subTest(content=content):
+                obj = Object(our_as1={
+                    **DM_BASE,
+                    'content': content,
+                })
+                self.assertEqual(('OK', 200), receive(from_user=alice, obj=obj))
+                self.assert_replied(OtherFake, alice, '?', "<p>Hi! I'm a friendly bot")
+
     def test_receive_did_atproto(self):
         self.make_user(id='bsky.brid.gy', cls=Web)
         alice = self.make_user(id='efake:alice', cls=ExplicitFake,