1 files changed, 74 insertions, 0 deletions
diff --git a/tests/test_spam_detector.py b/tests/test_spam_detector.py
new file mode 100644
index 0000000..4ac8591
--- /dev/null
+++ b/tests/test_spam_detector.py
@@ -0,0 +1,74 @@
+"""Tests for spam detection rule behavior."""
+
+import time
+from collections import OrderedDict
+from types import SimpleNamespace
+from typing import Optional
+from unittest.mock import MagicMock
+
+from umabot.bot import UmaBot
+from umabot.rules.spam_detector import SpamDetector
+
+
+def make_submission(post_id: str, username: str, created_utc: Optional[float] = None):
+    """Create a submission-like test object."""
+    return SimpleNamespace(
+        id=post_id,
+        author=SimpleNamespace(name=username),
+        created_utc=created_utc if created_utc is not None else time.time(),
+    )
+
+
+def make_config(max_posts_per_day: int = 3):
+    """Create a minimal config-like object for tests."""
+    return SimpleNamespace(
+        max_posts_per_day=max_posts_per_day,
+        subreddit_name="okbuddyumamusume",
+    )
+
+
+def test_spam_detector_removes_fourth_unique_post_same_day():
+    """Fourth unique post in the same UTC day should be removed."""
+    detector = SpamDetector(make_config())
+
+    assert detector.should_remove(make_submission("p1", "alice")) is False
+    assert detector.should_remove(make_submission("p2", "alice")) is False
+    assert detector.should_remove(make_submission("p3", "alice")) is False
+    assert detector.should_remove(make_submission("p4", "alice")) is True
+
+
+def test_spam_detector_does_not_double_count_same_submission():
+    """Seeing the same submission again should not increment the user's count."""
+    detector = SpamDetector(make_config())
+    submission = make_submission("p1", "alice")
+
+    assert detector.should_remove(submission) is False
+    assert detector.should_remove(submission) is False
+    assert detector.should_remove(make_submission("p2", "alice")) is False
+    assert detector.should_remove(make_submission("p3", "alice")) is False
+    assert detector.should_remove(make_submission("p4", "alice")) is True
+
+
+def test_spam_detector_ignores_old_submission_seen_today():
+    """Old submissions should not be treated as today's posts."""
+    detector = SpamDetector(make_config())
+    two_days_ago = time.time() - (2 * 24 * 60 * 60)
+
+    assert detector.should_remove(make_submission("old", "alice", two_days_ago)) is False
+    assert detector.should_remove(make_submission("p1", "alice")) is False
+    assert detector.should_remove(make_submission("p2", "alice")) is False
+    assert detector.should_remove(make_submission("p3", "alice")) is False
+
+
+def test_cleanup_processed_submissions_prunes_oldest_entries():
+    """Processed submission cleanup should keep the most recently seen IDs."""
+    bot = UmaBot.__new__(UmaBot)
+    bot.logger = MagicMock()
+    bot.processed_submissions = OrderedDict((str(i), None) for i in range(1005))
+
+    UmaBot._cleanup_processed_submissions(bot)
+
+    assert len(bot.processed_submissions) == 1000
+    assert "0" not in bot.processed_submissions
+    assert "4" not in bot.processed_submissions
+    assert "5" in bot.processed_submissions