fix(test): prevent stats_loop tests from hanging on CI

_capture_stats_loop called stats_loop() after the with-patch block
exited.  With all patches removed, DBWriter.connect() attempted a real
DB connection, failed, and the retry loop spun forever because
mock_event.is_set() was configured to return False.

Replace _capture_stats_loop with _run_stats_loop, which invokes
stats_loop() inside the patch context so DBWriter stays mocked
throughout the call.

Author: cchwala

parser/tests/test_main.py

@@ -121,8 +121,15 @@ def test_metadata_exception_is_swallowed(
     mock_batch.assert_called_once()
 
 
-def _capture_stats_loop(tmp_path, mock_event):
-    """Helper: run main() with CapturingThread + controlled stop_event, return stats_loop."""
+def _run_stats_loop(tmp_path, mock_event, *, configure_db=None):
+    """Run main(), then invoke the captured stats_loop closure under the same patches.
+
+    Calling stats_loop() inside the with-block is critical: if called after
+    the block exits, DBWriter and Config are unpatched, connect() fails against
+    a real DB, and the retry loop hangs forever.
+
+    Returns the MagicMock instance used as every DBWriter in the test.
+    """
     captured = {}
 
     class CapturingThread(threading.Thread):
@@ -134,15 +141,18 @@ def __init__(self, *args, target=None, name=None, **kwargs):
         def start(self):
             pass  # don't spawn real threads in unit tests
 
+    mock_db = MagicMock()
+
     with patch("parser.main.threading.Thread", CapturingThread), \
          patch("parser.main.threading.Event", return_value=mock_event), \
          patch("parser.main.FileManager"), \
          patch("parser.main.FileWatcher"), \
-         patch("parser.main.DBWriter") as MockDBWriter, \
+         patch("parser.main.DBWriter", return_value=mock_db), \
          patch("parser.main.Config.PARSER_ENABLED", True), \
          patch("parser.main.Config.PROCESS_EXISTING_ON_STARTUP", False), \
          patch("parser.main.Config.DATABASE_URL", "postgresql://test"), \
          patch("parser.main.Config.USER_ID", "test_user"), \
+         patch("parser.main.Config.STATS_REFRESH_INTERVAL", 60), \
          patch("parser.main.Config.INCOMING_DIR", tmp_path), \
          patch("parser.main.Config.ARCHIVED_DIR", tmp_path), \
          patch("parser.main.Config.QUARANTINE_DIR", tmp_path), \
@@ -151,8 +161,12 @@ def start(self):
             main()
         except (KeyboardInterrupt, SystemExit):
             pass
+        if configure_db is not None:
+            configure_db(mock_db)
+        if "stats_loop" in captured:
+            captured["stats_loop"]()
 
-    return captured.get("stats_loop"), MockDBWriter
+    return mock_db
 
 
 def test_stats_loop_calls_refresh_windowed_stats_on_startup(tmp_path):
@@ -161,12 +175,10 @@ def test_stats_loop_calls_refresh_windowed_stats_on_startup(tmp_path):
     mock_event.is_set.return_value = False  # connect loop: enter → connect succeeds → break
     mock_event.wait.return_value = True     # timer wait → loop exits immediately
 
-    stats_loop, MockDBWriter = _capture_stats_loop(tmp_path, mock_event)
-    assert stats_loop is not None
-    stats_loop()
+    mock_db = _run_stats_loop(tmp_path, mock_event)
 
-    MockDBWriter.return_value.refresh_windowed_stats.assert_called_once()
-    MockDBWriter.return_value.close.assert_called_once()
+    mock_db.refresh_windowed_stats.assert_called_once()
+    mock_db.close.assert_called()  # called by stats_loop (possibly also by main cleanup)
 
 
 def test_stats_loop_initial_refresh_error_is_swallowed(tmp_path):
@@ -175,10 +187,10 @@ def test_stats_loop_initial_refresh_error_is_swallowed(tmp_path):
     mock_event.is_set.return_value = False
     mock_event.wait.return_value = True
 
-    stats_loop, MockDBWriter = _capture_stats_loop(tmp_path, mock_event)
-    assert stats_loop is not None
-    MockDBWriter.return_value.refresh_windowed_stats.side_effect = Exception("stats error")
-    stats_loop()  # must not raise
+    def configure(db):
+        db.refresh_windowed_stats.side_effect = Exception("stats error")
+
+    _run_stats_loop(tmp_path, mock_event, configure_db=configure)  # must not raise
 
 
 def test_stats_loop_calls_refresh_windowed_stats_in_timer_loop(tmp_path):
@@ -188,12 +200,10 @@ def test_stats_loop_calls_refresh_windowed_stats_in_timer_loop(tmp_path):
     # First timer wait → False (enter loop body), second → True (exit)
     mock_event.wait.side_effect = [False, True]
 
-    stats_loop, MockDBWriter = _capture_stats_loop(tmp_path, mock_event)
-    assert stats_loop is not None
-    stats_loop()
+    mock_db = _run_stats_loop(tmp_path, mock_event)
 
     # startup call + 1 timer-loop call = 2 total
-    assert MockDBWriter.return_value.refresh_windowed_stats.call_count == 2
+    assert mock_db.refresh_windowed_stats.call_count == 2
 
 
 def test_stats_loop_creates_dbwriter_with_config_user_id(tmp_path):