1 files changed, 131 insertions, 0 deletions
diff --git a/tests/bot/rules/test_mentions.py b/tests/bot/rules/test_mentions.py
new file mode 100644
index 000000000..e1f904917
--- /dev/null
+++ b/tests/bot/rules/test_mentions.py
@@ -0,0 +1,131 @@
+from typing import Iterable, Optional
+
+import discord
+
+from bot.rules import mentions
+from tests.bot.rules import DisallowedCase, RuleTest
+from tests.helpers import MockMember, MockMessage, MockMessageReference
+
+
+def make_msg(
+    author: str,
+    total_user_mentions: int,
+    total_bot_mentions: int = 0,
+    *,
+    reference: Optional[MockMessageReference] = None
+) -> MockMessage:
+    """Makes a message from `author` with `total_user_mentions` user mentions and `total_bot_mentions` bot mentions."""
+    user_mentions = [MockMember() for _ in range(total_user_mentions)]
+    bot_mentions = [MockMember(bot=True) for _ in range(total_bot_mentions)]
+
+    mentions = user_mentions + bot_mentions
+    if reference is not None:
+        # For the sake of these tests we assume that all references are mentions.
+        mentions.append(reference.resolved.author)
+        msg_type = discord.MessageType.reply
+    else:
+        msg_type = discord.MessageType.default
+
+    return MockMessage(author=author, mentions=mentions, reference=reference, type=msg_type)
+
+
+class TestMentions(RuleTest):
+    """Tests applying the `mentions` antispam rule."""
+
+    def setUp(self):
+        self.apply = mentions.apply
+        self.config = {
+            "max": 2,
+            "interval": 10,
+        }
+
+    async def test_mentions_within_limit(self):
+        """Messages with an allowed amount of mentions."""
+        cases = (
+            [make_msg("bob", 0)],
+            [make_msg("bob", 2)],
+            [make_msg("bob", 1), make_msg("bob", 1)],
+            [make_msg("bob", 1), make_msg("alice", 2)],
+        )
+
+        await self.run_allowed(cases)
+
+    async def test_mentions_exceeding_limit(self):
+        """Messages with a higher than allowed amount of mentions."""
+        cases = (
+            DisallowedCase(
+                [make_msg("bob", 3)],
+                ("bob",),
+                3,
+            ),
+            DisallowedCase(
+                [make_msg("alice", 2), make_msg("alice", 0), make_msg("alice", 1)],
+                ("alice",),
+                3,
+            ),
+            DisallowedCase(
+                [make_msg("bob", 2), make_msg("alice", 3), make_msg("bob", 2)],
+                ("bob",),
+                4,
+            ),
+            DisallowedCase(
+                [make_msg("bob", 3, 1)],
+                ("bob",),
+                3,
+            ),
+            DisallowedCase(
+                [make_msg("bob", 3, reference=MockMessageReference())],
+                ("bob",),
+                3,
+            ),
+            DisallowedCase(
+                [make_msg("bob", 3, reference=MockMessageReference(reference_author_is_bot=True))],
+                ("bob",),
+                3
+            )
+        )
+
+        await self.run_disallowed(cases)
+
+    async def test_ignore_bot_mentions(self):
+        """Messages with an allowed amount of mentions, also containing bot mentions."""
+        cases = (
+            [make_msg("bob", 0, 3)],
+            [make_msg("bob", 2, 1)],
+            [make_msg("bob", 1, 2), make_msg("bob", 1, 2)],
+            [make_msg("bob", 1, 5), make_msg("alice", 2, 5)]
+        )
+
+        await self.run_allowed(cases)
+
+    async def test_ignore_reply_mentions(self):
+        """Messages with an allowed amount of mentions in the content, also containing reply mentions."""
+        cases = (
+            [
+                make_msg("bob", 2, reference=MockMessageReference())
+            ],
+            [
+                make_msg("bob", 2, reference=MockMessageReference(reference_author_is_bot=True))
+            ],
+            [
+                make_msg("bob", 2, reference=MockMessageReference()),
+                make_msg("bob", 0, reference=MockMessageReference())
+            ],
+            [
+                make_msg("bob", 2, reference=MockMessageReference(reference_author_is_bot=True)),
+                make_msg("bob", 0, reference=MockMessageReference(reference_author_is_bot=True))
+            ]
+        )
+
+        await self.run_allowed(cases)
+
+    def relevant_messages(self, case: DisallowedCase) -> Iterable[MockMessage]:
+        last_message = case.recent_messages[0]
+        return tuple(
+            msg
+            for msg in case.recent_messages
+            if msg.author == last_message.author
+        )
+
+    def get_report(self, case: DisallowedCase) -> str:
+        return f"sent {case.n_violations} mentions in {self.config['interval']}s"