fix(dashboards): normalize naive/aware datetimes in resource task ordering

backend/src/services/__tests__/test_resource_service.py

@@ -9,7 +9,7 @@
 
 import pytest
 from unittest.mock import MagicMock, patch, AsyncMock
-from datetime import datetime
+from datetime import datetime, timezone
 
 
 # [DEF:test_get_dashboards_with_status:Function]
@@ -269,4 +269,71 @@ def test_get_last_task_for_resource_no_match():
 # [/DEF:test_get_last_task_for_resource_no_match:Function]
 
 
+# [DEF:test_get_dashboards_with_status_handles_mixed_naive_and_aware_task_datetimes:Function]
+# @TEST: get_dashboards_with_status handles mixed naive/aware datetimes without comparison errors.
+# @PRE: Task list includes both timezone-aware and timezone-naive timestamps.
+# @POST: Latest task is selected deterministically and no exception is raised.
+@pytest.mark.asyncio
+async def test_get_dashboards_with_status_handles_mixed_naive_and_aware_task_datetimes():
+    with patch("src.services.resource_service.SupersetClient") as mock_client, \
+         patch("src.services.resource_service.GitService"):
+
+        from src.services.resource_service import ResourceService
+
+        service = ResourceService()
+        mock_client.return_value.get_dashboards_summary.return_value = [
+            {"id": 1, "title": "Dashboard 1", "slug": "dash-1"}
+        ]
+
+        task_naive = MagicMock()
+        task_naive.id = "task-naive"
+        task_naive.plugin_id = "llm_dashboard_validation"
+        task_naive.status = "SUCCESS"
+        task_naive.params = {"dashboard_id": "1", "environment_id": "prod"}
+        task_naive.started_at = datetime(2024, 1, 1, 10, 0, 0)
+
+        task_aware = MagicMock()
+        task_aware.id = "task-aware"
+        task_aware.plugin_id = "llm_dashboard_validation"
+        task_aware.status = "SUCCESS"
+        task_aware.params = {"dashboard_id": "1", "environment_id": "prod"}
+        task_aware.started_at = datetime(2024, 1, 1, 12, 0, 0, tzinfo=timezone.utc)
+
+        env = MagicMock()
+        env.id = "prod"
+
+        result = await service.get_dashboards_with_status(env, [task_naive, task_aware])
+
+        assert result[0]["last_task"]["task_id"] == "task-aware"
+# [/DEF:test_get_dashboards_with_status_handles_mixed_naive_and_aware_task_datetimes:Function]
+
+
+# [DEF:test_get_last_task_for_resource_handles_mixed_naive_and_aware_created_at:Function]
+# @TEST: _get_last_task_for_resource handles mixed naive/aware created_at values.
+# @PRE: Matching tasks include naive and aware created_at timestamps.
+# @POST: Latest task is returned without raising datetime comparison errors.
+def test_get_last_task_for_resource_handles_mixed_naive_and_aware_created_at():
+    from src.services.resource_service import ResourceService
+
+    service = ResourceService()
+
+    task_naive = MagicMock()
+    task_naive.id = "task-old"
+    task_naive.status = "SUCCESS"
+    task_naive.params = {"resource_id": "dashboard-1"}
+    task_naive.created_at = datetime(2024, 1, 1, 10, 0, 0)
+
+    task_aware = MagicMock()
+    task_aware.id = "task-new"
+    task_aware.status = "RUNNING"
+    task_aware.params = {"resource_id": "dashboard-1"}
+    task_aware.created_at = datetime(2024, 1, 1, 12, 0, 0, tzinfo=timezone.utc)
+
+    result = service._get_last_task_for_resource("dashboard-1", [task_naive, task_aware])
+
+    assert result is not None
+    assert result["task_id"] == "task-new"
+# [/DEF:test_get_last_task_for_resource_handles_mixed_naive_and_aware_created_at:Function]
+
+
 # [/DEF:backend.src.services.__tests__.test_resource_service:Module]

backend/src/services/resource_service.py

@@ -10,7 +10,7 @@
 
 # [SECTION: IMPORTS]
 from typing import List, Dict, Optional, Any
-from datetime import datetime
+from datetime import datetime, timezone
 from ..core.superset_client import SupersetClient
 from ..core.task_manager.models import Task
 from ..services.git_service import GitService
@@ -179,12 +179,12 @@ class ResourceService:
             return None
 
         def _task_time(task_obj: Any) -> datetime:
-            return (
+            raw_time = (
                 getattr(task_obj, "started_at", None)
                 or getattr(task_obj, "finished_at", None)
                 or getattr(task_obj, "created_at", None)
-                or datetime.min
             )
+            return self._normalize_datetime_for_compare(raw_time)
 
         last_task = max(matched_tasks, key=_task_time)
         raw_result = getattr(last_task, "result", None)
@@ -229,6 +229,20 @@ class ResourceService:
             return status_text
         return "UNKNOWN"
     # [/DEF:_normalize_validation_status:Function]
+
+    # [DEF:_normalize_datetime_for_compare:Function]
+    # @PURPOSE: Normalize datetime values to UTC-aware values for safe comparisons.
+    # @PRE: value may be datetime or any scalar.
+    # @POST: Returns UTC-aware datetime; non-datetime values map to minimal UTC datetime.
+    # @PARAM: value (Any) - Candidate datetime-like value.
+    # @RETURN: datetime - UTC-aware comparable datetime.
+    def _normalize_datetime_for_compare(self, value: Any) -> datetime:
+        if isinstance(value, datetime):
+            if value.tzinfo is None:
+                return value.replace(tzinfo=timezone.utc)
+            return value.astimezone(timezone.utc)
+        return datetime.min.replace(tzinfo=timezone.utc)
+    # [/DEF:_normalize_datetime_for_compare:Function]
     
     # [DEF:get_datasets_with_status:Function]
     # @PURPOSE: Fetch datasets from environment with mapping progress and last task status
@@ -391,8 +405,11 @@ class ResourceService:
         if not resource_tasks:
             return None
         
-        # Get most recent task
-        last_task = max(resource_tasks, key=lambda t: t.created_at)
+        # Get most recent task with timezone-safe comparison.
+        last_task = max(
+            resource_tasks,
+            key=lambda t: self._normalize_datetime_for_compare(getattr(t, "created_at", None)),
+        )
         
         return {
             'task_id': str(last_task.id),