fix: only sub_doesnt_exist_bot answers nested comments

AGENTS.md

@@ -45,9 +45,13 @@ auxiliary bot's PRAW instance (`get_comment_with_different_praw_instance`). All
    - Trigger: Comment links to a target subreddit that already contains a post with the exact same URL/content or visually matching image.
    - Behavior: Detects existing posts via Reddit search and self-hosted perceptual image hashing (`imagehash`), replying with a link to the prior post.
 
-> [!WARNING]
-> Auxiliary bots reply to matching comments at **any depth**. The top-level-only check
-> (`comment.parent_id == comment.link_id`) runs **after** the auxiliary dispatch and gates only the DB insert.
+> [!NOTE]
+> Only **top-level** comments (`comment.parent_id == comment.link_id`, a direct answer to the post) count as
+> recommendations and get a reply from `same_subreddit_bot` or `same_post_bot`. `sub_doesnt_exist_bot` is the
+> one bot that also answers replies to other comments. For those, Phase 1 only checks whether the target exists
+> (`get_posts_with_same_content(..., existence_only=True)`: the URL search, no duplicate scan).
+> Every bot requires the **whole** body to be the subreddit reference (the matching rule above). A comment
+> edited after the bot answered (e.g. `r/name` later extended with `\n\nWait...`) keeps that answer.
 
 ---
 
@@ -89,14 +93,18 @@ flowchart TD
     T -->|Yes| X3["ignore"]
     T -->|No| BL{"Source or target in\nSUB_BLACKLIST?\n(case-insensitive)"}
     BL -->|Yes| X4["ignore"]
-    BL -->|No| SS{"target == source\n(case-insensitive)?"}
+    BL -->|No| TL{"Top-level comment?"}
+    TL -->|No| SSN{"target == source\n(case-insensitive)?"}
+    SSN -->|Yes| X5["ignore"]
+    SSN -->|No| EX["get_posts_with_same_content(existence_only=True)\n1 URL search"]
+    EX -->|SUBREDDIT_DOES_NOT_EXIST| A3
+    EX -->|otherwise| X6["ignore"]
+    TL -->|Yes| SS{"target == source\n(case-insensitive)?"}
     SS -->|Yes| A1["same_subreddit_bot reply"]
     SS -->|No| DUP["get_posts_with_same_content()\n1 URL search + 1 other-discussions call\n+ image/video-hash scan of\n100 newest + 100 all-time top posts"]
     DUP -->|posts_found| A2["same_post_bot reply"]
     DUP -->|SUBREDDIT_DOES_NOT_EXIST| A3["sub_doesnt_exist_bot reply"]
-    DUP -->|otherwise| TL{"Top-level comment?"}
-    TL -->|No| X5["ignore"]
-    TL -->|Yes| DB[("insert_scraped_comment(permalink, target)")]
+    DUP -->|otherwise| DB[("insert_scraped_comment(permalink, target)")]
 ```
 
 Note: a private target (`SUBREDDIT_IS_PRIVATE`) is **still inserted** in Phase 1. Phase 2 deletes it later.
@@ -106,7 +114,7 @@ A banned target (a 404 whose body says `"reason": "banned"`, `SUBREDDIT_IS_BANNE
 ### Phase Details
 - **Phase 1 ([`src/racb/phases/phase1.py`](./src/racb/phases/phase1.py)):**
   - Continuous streaming from `reddit.subreddit('all').stream.comments(skip_existing=True, pause_after=-1)`.
-  - Filters: Discards moderator comments, submissions with meta-phrases (`sub`, `subreddit`), and blacklisted subreddits ([`src/racb/constants.py`](./src/racb/constants.py), compared case-insensitively by `is_crosspost_blocked`). Non-top-level comments (`comment.parent_id != comment.link_id`) are discarded only **after** auxiliary-bot dispatch (see the warning in section 1).
+  - Filters: Discards moderator comments, submissions with meta-phrases (`sub`, `subreddit`), and blacklisted subreddits ([`src/racb/constants.py`](./src/racb/constants.py), compared case-insensitively by `is_crosspost_blocked`). Non-top-level comments (`comment.parent_id != comment.link_id`) can only get a `sub_doesnt_exist_bot` reply and are never stored (see the note in section 1).
   - Qualified suggestions are stored via stored procedure `insert_scraped_comment(permalink, target_subreddit)`.
   - Phases 2 and 3 re-parse the target from the live comment body and reject the row
     (`TARGET_SUBREDDIT_CHANGED`) if it no longer equals the stored target, case-insensitively. This blocks

changelog.d/+top-level-only-replies.fixed.md

@@ -0,0 +1 @@
+**Bots No Longer Answer Nested Comments:** `same_subreddit_bot` and `same_post_bot` replied to a subreddit reference anywhere in a comment thread, not only to comments answering the post. They now answer top-level comments only, like the crosspost recommendation itself. `sub_doesnt_exist_bot` still answers at any depth, and for those replies Phase 1 now only checks that the target exists instead of running the full duplicate scan.

src/racb/phases/phase1.py

@@ -31,7 +31,13 @@ def handle_incoming_comment(comment, metrics=None):
     if is_crosspost_blocked(source_subreddit, target_subreddit):
         return
 
+    # Only sub_doesnt_exist_bot answers replies to other comments. Every other bot, and the crosspost
+    # recommendation itself, only counts comments that answer the post directly
+    top_level = is_top_level_comment(comment)
+
     if target_subreddit.lower() == source_subreddit:
+        if not top_level:
+            return None
         if not config.is_bot_enabled(reddit.SAME_SUBREDDIT_BOT_NAME):
             logger.info(f'Found "same subreddit" comment ({reddit.full_url(comment.permalink)}); same_subreddit_bot is disabled.')
             return None
@@ -41,8 +47,9 @@ def handle_incoming_comment(comment, metrics=None):
             metrics.record_aux()
         return reply
 
-    result_obj = get_posts_with_same_content(comment, target_subreddit)
-    if result_obj.posts_found:
+    # A reply only needs to know whether the target exists, which the first search tells
+    result_obj = get_posts_with_same_content(comment, target_subreddit, existence_only=not top_level)
+    if top_level and result_obj.posts_found:
         if not config.is_bot_enabled(reddit.SAME_POST_BOT_NAME):
             logger.info(f'Found post with duplicate content in r/{target_subreddit} ({reddit.full_url(comment.permalink)}); same_post_bot is disabled.')
             return None
@@ -108,7 +115,8 @@ def check_pattern(comment):
 def get_posts_with_same_content(comment, subreddit, media_scan_since=None,
                                 media_scan_limit=duplicate_detector.QUICK_SCAN_NEWEST_LIMIT,
                                 media_scan_top_limit=duplicate_detector.QUICK_SCAN_TOP_LIMIT,
-                                media_scan_top_time_filters=('all',), search_titles=False):
+                                media_scan_top_time_filters=('all',), search_titles=False,
+                                existence_only=False):
     """Looks for posts in `subreddit` that link to the same URL or, for an image or video post, look the same.
 
     Also counts as the same content: a post in `subreddit` that Reddit lists among the submission's "other
@@ -118,6 +126,9 @@ def get_posts_with_same_content(comment, subreddit, media_scan_since=None,
     The picture comparison reads at most `media_scan_limit` of the newest posts, stopping at the first one older
     than `media_scan_since` (a Unix timestamp), plus the `media_scan_top_limit` top posts of each period in
     `media_scan_top_time_filters`. Its outcome is kept in `media_scan` (None if nothing was compared).
+
+    With `existence_only`, it stops after the URL search, which is enough to fill `unable_to_search` and
+    `unable_to_search_reason`; `posts_found` then stays False.
     """
     class Result:
         posts_found = False
@@ -166,6 +177,9 @@ class Result:
         else:
             raise
 
+    if existence_only:
+        return result
+
     if len(submissions) > 0:
         result.posts_found = True
         result.posts = submissions

tests/unit/test_phase1.py

@@ -22,6 +22,13 @@ def test_check_pattern(make_mock_comment):
     assert phase1.check_pattern(make_mock_comment(body='r/this_subreddit_name_is_way_too_long_for_reddit')) is None
     assert phase1.check_pattern(make_mock_comment(body='just some text')) is None
 
+    # Anything besides the reference, on the same line or another one, disqualifies the comment
+    assert phase1.check_pattern(make_mock_comment(body='r/brothrewinafunfact\n\nWait...')) is None
+    assert phase1.check_pattern(make_mock_comment(body='Wait...\n\nr/brothrewinafunfact')) is None
+    assert phase1.check_pattern(make_mock_comment(body='r/funny\nr/pics')) is None
+    assert phase1.check_pattern(make_mock_comment(body='r/funny.')) is None
+    assert phase1.check_pattern(make_mock_comment(body=' r/funny')) is None
+
 
 @pytest.mark.unit
 def test_is_mod_post(make_mock_comment):
@@ -469,3 +476,92 @@ def test_banned_target_gets_no_sub_doesnt_exist_reply(make_mock_comment):
             patch('racb.phases.phase1.db.add_comment'):
         phase1.handle_incoming_comment(comment)
     mock_reply.assert_not_called()
+
+
+NESTED = dict(parent_id='t1_c999', link_id='t3_sub123')
+
+
+@pytest.mark.unit
+def test_same_subreddit_bot_ignores_nested_comments(make_mock_comment):
+    comment = make_mock_comment(body='r/test_source', subreddit='test_source', **NESTED)
+    with patch('racb.phases.phase1.reply_to_source_equals_target_comment') as mock_reply, \
+            patch('racb.phases.phase1.get_posts_with_same_content') as mock_search, \
+            patch('racb.phases.phase1.db.add_comment') as mock_add:
+        assert phase1.handle_incoming_comment(comment) is None
+    mock_reply.assert_not_called()
+    mock_search.assert_not_called()
+    mock_add.assert_not_called()
+
+
+@pytest.mark.unit
+def test_nested_comment_only_checks_that_the_target_exists(make_mock_comment):
+    comment = make_mock_comment(body='r/target_sub', subreddit='test_source', **NESTED)
+    mock_reddit = MagicMock()
+    mock_reddit.subreddit.return_value.search.return_value = [MagicMock(permalink='/r/target_sub/comments/dup1/')]
+    with patch('racb.core.reddit.get_reddit_instance', return_value=mock_reddit), \
+            patch('racb.phases.phase1.find_other_discussions') as mock_other_discussions, \
+            patch('racb.core.duplicate_detector.scan_subreddit_for_duplicates') as mock_scan, \
+            patch('racb.phases.phase1.reply_to_same_content_post_comment') as mock_reply, \
+            patch('racb.phases.phase1.db.add_comment') as mock_add:
+        assert phase1.handle_incoming_comment(comment) is None
+    mock_reply.assert_not_called()
+    mock_other_discussions.assert_not_called()
+    mock_scan.assert_not_called()
+    mock_add.assert_not_called()
+
+
+@pytest.mark.unit
+def test_same_post_bot_ignores_nested_comments(make_mock_comment):
+    comment = make_mock_comment(body='r/target_sub', subreddit='test_source', **NESTED)
+    mock_res = MagicMock(posts_found=True, posts=[MagicMock(permalink='/r/target_sub/comments/dup1/')])
+    with patch('racb.phases.phase1.get_posts_with_same_content', return_value=mock_res) as mock_search, \
+            patch('racb.phases.phase1.reply_to_same_content_post_comment') as mock_reply, \
+            patch('racb.phases.phase1.db.add_comment') as mock_add:
+        assert phase1.handle_incoming_comment(comment) is None
+    assert mock_search.call_args.kwargs['existence_only'] is True
+    mock_reply.assert_not_called()
+    mock_add.assert_not_called()
+
+
+@pytest.mark.unit
+def test_sub_doesnt_exist_bot_still_answers_nested_comments(make_mock_comment):
+    comment = make_mock_comment(body='r/nonexistent_sub_xyz', subreddit='test_source', **NESTED)
+    mock_res = MagicMock(posts_found=False, unable_to_search=True, unable_to_search_reason='SUBREDDIT_DOES_NOT_EXIST')
+    with patch('racb.phases.phase1.get_posts_with_same_content', return_value=mock_res), \
+            patch('racb.phases.phase1.reply_to_nonexistent_target_subreddit_comment') as mock_reply, \
+            patch('racb.phases.phase1.db.add_comment') as mock_add:
+        phase1.handle_incoming_comment(comment)
+    mock_reply.assert_called_once_with(comment, 'nonexistent_sub_xyz')
+    mock_add.assert_not_called()
+
+
+@pytest.mark.unit
+def test_nested_recommendation_is_not_stored(make_mock_comment):
+    comment = make_mock_comment(body='r/target_sub', subreddit='test_source', **NESTED)
+    mock_res = MagicMock(posts_found=False, unable_to_search=False)
+    with patch('racb.phases.phase1.get_posts_with_same_content', return_value=mock_res), \
+            patch('racb.phases.phase1.db.add_comment') as mock_add:
+        assert phase1.handle_incoming_comment(comment) is None
+    mock_add.assert_not_called()
+
+
+@pytest.mark.unit
+def test_top_level_comment_gets_the_full_duplicate_check(make_mock_comment):
+    comment = make_mock_comment(body='r/target_sub', subreddit='test_source')
+    mock_res = MagicMock(posts_found=False, unable_to_search=False)
+    with patch('racb.phases.phase1.get_posts_with_same_content', return_value=mock_res) as mock_search, \
+            patch('racb.phases.phase1.db.add_comment'):
+        phase1.handle_incoming_comment(comment)
+    assert mock_search.call_args.kwargs['existence_only'] is False
+
+
+@pytest.mark.unit
+def test_comment_with_extra_text_gets_no_reply(make_mock_comment):
+    comment = make_mock_comment(body='r/test_source\n\nWait...', subreddit='test_source')
+    with patch('racb.phases.phase1.reply_to_source_equals_target_comment') as mock_reply, \
+            patch('racb.phases.phase1.get_posts_with_same_content') as mock_search, \
+            patch('racb.phases.phase1.db.add_comment') as mock_add:
+        assert phase1.handle_incoming_comment(comment) is None
+    mock_reply.assert_not_called()
+    mock_search.assert_not_called()
+    mock_add.assert_not_called()