Fix bug in db fixture

docs/changes/2089.bugfix.md

@@ -0,0 +1 @@
+Fixed CI-only DB unit-test flakiness by hardening conftest.py database-test detection so DatabaseHandler is no longer accidentally globally mocked for tests/unit_tests/db/*.

pyproject.toml

@@ -280,6 +280,7 @@ ignore-words-list = "chec,arrang,livetime"
 [tool.pytest]
 ini_options.markers = [
   "uses_model_database: test uses model parameter database.",
+  "db_unit_test: test belongs to unit_tests/db and must not use global DatabaseHandler patching.",
 ]
 ini_options.minversion = "6.0"
 ini_options.norecursedirs = [

tests/unit_tests/conftest.py

@@ -31,8 +31,39 @@
 from simtools.runners.corsika_runner import CorsikaRunner
 
 logger = logging.getLogger()
+REAL_DATABASE_HANDLER_CLASS = db_handler.DatabaseHandler
 
-UNIT_TEST_DB = "unit_tests/db"
+
+def pytest_collection_modifyitems(items):
+    """Tag db unit tests with a stable marker for fixture routing."""
+
+    def _is_db_item(item):
+        path = getattr(item, "path", None)
+        if path is None:
+            return False
+        parts = tuple(path.parts)
+        db_parts = ("tests", "unit_tests", "db")
+        return any(parts[idx : idx + 3] == db_parts for idx in range(max(len(parts) - 2, 0)))
+
+    for item in items:
+        if _is_db_item(item):
+            item.add_marker("db_unit_test")
+
+
+def _is_db_unit_test(request):
+    """Return True when the current test carries the db_unit_test marker."""
+    node = getattr(request, "node", None)
+    if node is None:
+        return False
+
+    if node.get_closest_marker("db_unit_test") is not None:
+        return True
+
+    test_file = ""
+    location = getattr(node, "location", None)
+    if location:
+        test_file = str(location[0]).replace("\\", "/")
+    return test_file.startswith("tests/unit_tests/db/")
 
 
 @functools.lru_cache
@@ -355,11 +386,8 @@ def mock_db_handler(request):
     Returns a MagicMock configured with typical DatabaseHandler methods.
     Tests in tests/unit_tests/db/ receive a real DatabaseHandler instance.
     """
-    test_file_path = str(request.node.fspath)
-    if UNIT_TEST_DB in test_file_path:
-        db_instance = request.getfixturevalue("db")
-        db_instance.get_model_versions = MagicMock(return_value=["1.0.0", "5.0.0", "6.0.0"])
-        return db_instance
+    if _is_db_unit_test(request):
+        return request.getfixturevalue("db")
 
     # Load mock data from JSON files
     mock_parameters = _apply_mock_param_defaults(_load_mock_db_json("mock_parameters.json"))
@@ -442,11 +470,13 @@ def patch_database_handler(request, mocker):
     Tests in tests/unit_tests/db/ are excluded from this mocking.
     Also patches model parameter schema validation to avoid schema version mismatches.
     """
-    test_file_path = str(request.node.fspath)
-
     # Skip mocking for tests in db/ directory
-    if UNIT_TEST_DB in test_file_path:
-        yield
+    if _is_db_unit_test(request):
+        with mock.patch(
+            "simtools.db.db_handler.DatabaseHandler",
+            new=REAL_DATABASE_HANDLER_CLASS,
+        ):
+            yield
         return
 
     mock_db_handler = request.getfixturevalue("mock_db_handler")
@@ -462,8 +492,7 @@ def patch_database_handler(request, mocker):
 def db(request):
     """Database object with configuration from settings.config.db_handler."""
 
-    test_file_path = str(request.node.fspath)
-    if UNIT_TEST_DB not in test_file_path:
+    if not _is_db_unit_test(request):
         db_instance = db_handler.DatabaseHandler()
         yield db_instance
         return
@@ -503,7 +532,7 @@ def db(request):
     mock_mongo_client.close = MagicMock()
 
     with patch("simtools.db.mongo_db.MongoClient", return_value=mock_mongo_client):
-        db_instance = db_handler.DatabaseHandler()
+        db_instance = REAL_DATABASE_HANDLER_CLASS()
         MongoDBHandler.db_client = MongoDBHandler.db_client or mock_mongo_client
         yield db_instance
         # Explicitly close the mock client to avoid un-raisable exception warnings

tests/unit_tests/db/test_db_handler.py

@@ -10,8 +10,11 @@
 from simtools.db.mongo_db import MongoDBHandler
 from simtools.utils import names
 
-# Suppress warnings
-pytestmark = pytest.mark.filterwarnings("ignore::pytest.PytestUnraisableExceptionWarning")
+# Suppress warnings and mark this module as db unit tests.
+pytestmark = [
+    pytest.mark.filterwarnings("ignore::pytest.PytestUnraisableExceptionWarning"),
+    pytest.mark.db_unit_test,
+]
 
 logger = logging.getLogger()
 

tests/unit_tests/db/test_db_model_upload.py

@@ -8,6 +8,8 @@
 
 import simtools.db.db_model_upload as db_model_upload
 
+pytestmark = pytest.mark.db_unit_test
+
 
 @patch("simtools.db.db_model_upload.ascii_handler.collect_data_from_file")
 def test_add_values_from_json_to_db(mock_collect_data_from_file):

tests/unit_tests/db/test_mongo_db.py

@@ -7,7 +7,10 @@
 
 from simtools.db import mongo_db
 
-pytestmark = pytest.mark.filterwarnings("ignore::pytest.PytestUnraisableExceptionWarning")
+pytestmark = [
+    pytest.mark.filterwarnings("ignore::pytest.PytestUnraisableExceptionWarning"),
+    pytest.mark.db_unit_test,
+]
 
 
 @pytest.fixture(autouse=True)