reject empty schedule_days with 422

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

tests/api/test_scheduler_endpoints.py

@@ -252,18 +252,17 @@ class TestUpdateSchedulerConfig:
         assert response.status_code == 422
 
     @pytest.mark.asyncio
-    async def test_empty_schedule_days_accepted(
+    async def test_empty_schedule_days_rejected(
         self, authenticated_client, mock_config_service, mock_scheduler_service
     ):
-        """Empty schedule_days list is valid (disables the cron job)."""
+        """Empty schedule_days list is invalid and returns 422."""
         payload = {"enabled": True, "schedule_days": []}
 
         with patch("src.server.api.scheduler.get_config_service", return_value=mock_config_service), \
              patch("src.server.api.scheduler.get_scheduler_service", return_value=mock_scheduler_service):
             response = await authenticated_client.post("/api/scheduler/config", json=payload)
 
-        assert response.status_code == 200
-        assert response.json()["config"]["schedule_days"] == []
+        assert response.status_code == 422
 
     @pytest.mark.asyncio
     async def test_update_enable_disable_toggle(

tests/unit/test_scheduler_config_model.py

@@ -68,8 +68,8 @@ class TestSchedulerConfigValidScheduleDays:
         assert config.schedule_days == ALL_DAYS
 
     def test_empty_list(self) -> None:
-        config = SchedulerConfig(schedule_days=[])
-        assert config.schedule_days == []
+        with pytest.raises(ValidationError):
+            SchedulerConfig(schedule_days=[])
 
 
 class TestSchedulerConfigInvalidScheduleDays:

tests/unit/test_scheduler_service.py

@@ -12,6 +12,7 @@ from datetime import datetime, timezone
 from unittest.mock import AsyncMock, MagicMock, Mock, call, patch
 
 import pytest
+from pydantic import ValidationError
 from apscheduler.triggers.cron import CronTrigger
 
 from src.server.models.config import AppConfig, SchedulerConfig
@@ -84,11 +85,11 @@ class TestBuildCronTrigger:
             assert day in fields["day_of_week"]
 
     def test_empty_days_returns_none(self, scheduler_service):
-        scheduler_service._config = SchedulerConfig(
-            schedule_time="03:00",
-            schedule_days=[],
-        )
-        assert scheduler_service._build_cron_trigger() is None
+        with pytest.raises(ValidationError):
+            SchedulerConfig(
+                schedule_time="03:00",
+                schedule_days=[],
+            )
 
     def test_no_config_returns_none(self, scheduler_service):
         scheduler_service._config = None
@@ -136,25 +137,8 @@ class TestStart:
 class TestStartEmptyDays:
     @pytest.mark.asyncio
     async def test_no_job_added_when_days_empty(self, scheduler_service):
-        with patch(
-            "src.server.services.scheduler.scheduler_service.get_config_service"
-        ) as mock_cs, patch(
-            "src.server.services.scheduler.scheduler_service.AsyncIOScheduler"
-        ) as MockScheduler:
-            svc = Mock()
-            svc.load_config.return_value = _make_app_config(
-                enabled=True, schedule_days=[]
-            )
-            mock_cs.return_value = svc
-
-            mock_sched = MagicMock()
-            MockScheduler.return_value = mock_sched
-
-            await scheduler_service.start()
-
-            mock_sched.add_job.assert_not_called()
-            mock_sched.start.assert_called_once()
-            assert scheduler_service._is_running is True
+        with pytest.raises(ValidationError):
+            _make_app_config(enabled=True, schedule_days=[])
 
 
 # ---------------------------------------------------------------------------
@@ -224,19 +208,10 @@ class TestReloadConfig:
 
 class TestReloadConfigEmptyDays:
     def test_removes_job_when_days_empty(self, scheduler_service):
-        mock_sched = MagicMock()
-        mock_sched.running = True
-        mock_sched.get_job.return_value = Mock()  # job exists
-        scheduler_service._scheduler = mock_sched
-        scheduler_service._config = SchedulerConfig(
-            schedule_time="03:00", schedule_days=ALL_DAYS
-        )
-
-        new_config = SchedulerConfig(schedule_time="03:00", schedule_days=[])
-        scheduler_service.reload_config(new_config)
-
-        mock_sched.remove_job.assert_called_once_with(_JOB_ID)
-        mock_sched.reschedule_job.assert_not_called()
+        # Empty schedule_days is now rejected at validation time.
+        # Config with empty days can never be loaded, so this scenario
+        # cannot occur — test removed.
+        pass
 
 
 # ---------------------------------------------------------------------------