test: add tests for trigger_cron timezone functionality

Add unit tests for create_next_triggers function to improve coverage:
- Test timezone handling (America/New_York, UTC, Europe/London)
- Test None timezone defaults to UTC
- Test DuplicateKeyError handling
- Test datetime object validation
- Test multiple trigger creation

These tests cover the new timezone-aware trigger scheduling logic.

Signed-off-by: Sparsh <sparsh.raj30@gmail.com>

Author: spa-raj

…unit/tasks/test_create_crons_coverage.py …er/tests/unit/tasks/test_create_crons.pystate-manager/tests/unit/tasks/test_create_crons_coverage.py renamed to state-manager/tests/unit/tasks/test_create_crons.py state-manager/tests/unit/tasks/test_create_crons_coverage.py renamed to state-manager/tests/unit/tasks/test_create_crons.py

@@ -0,0 +1,188 @@
+"""
+Tests for trigger_cron functions to improve code coverage.
+These are pure unit tests that mock database operations.
+Environment variables are provided by CI (see .github/workflows/test-state-manager.yml).
+"""
+import pytest
+from unittest.mock import MagicMock, AsyncMock, patch
+from datetime import datetime
+
+from app.tasks.trigger_cron import create_next_triggers
+
+
+@pytest.mark.asyncio
+async def test_create_next_triggers_with_america_new_york_timezone():
+    """Test create_next_triggers processes America/New_York timezone correctly"""
+    trigger = MagicMock()
+    trigger.expression = "0 9 * * *"
+    trigger.timezone = "America/New_York"
+    trigger.trigger_time = datetime(2025, 10, 4, 13, 0, 0)  # Naive UTC time
+    trigger.graph_name = "test_graph"
+    trigger.namespace = "test_namespace"
+
+    cron_time = datetime(2025, 10, 6, 0, 0, 0)
+
+    with patch('app.tasks.trigger_cron.DatabaseTriggers') as mock_db_class:
+        mock_instance = MagicMock()
+        mock_instance.insert = AsyncMock()
+        mock_db_class.return_value = mock_instance
+
+        await create_next_triggers(trigger, cron_time)
+
+        # Verify DatabaseTriggers was instantiated with timezone
+        assert mock_db_class.called
+        call_kwargs = mock_db_class.call_args[1]
+        assert call_kwargs['timezone'] == "America/New_York"
+        assert call_kwargs['expression'] == "0 9 * * *"
+
+
+@pytest.mark.asyncio
+async def test_create_next_triggers_with_utc_timezone():
+    """Test create_next_triggers with UTC timezone"""
+    trigger = MagicMock()
+    trigger.expression = "0 9 * * *"
+    trigger.timezone = "UTC"
+    trigger.trigger_time = datetime(2025, 10, 4, 9, 0, 0)
+    trigger.graph_name = "test_graph"
+    trigger.namespace = "test_namespace"
+
+    cron_time = datetime(2025, 10, 6, 0, 0, 0)
+
+    with patch('app.tasks.trigger_cron.DatabaseTriggers') as mock_db_class:
+        mock_instance = MagicMock()
+        mock_instance.insert = AsyncMock()
+        mock_db_class.return_value = mock_instance
+
+        await create_next_triggers(trigger, cron_time)
+
+        # Verify timezone was passed correctly
+        call_kwargs = mock_db_class.call_args[1]
+        assert call_kwargs['timezone'] == "UTC"
+
+
+@pytest.mark.asyncio
+async def test_create_next_triggers_with_none_timezone_defaults_to_utc():
+    """Test create_next_triggers with None timezone defaults to UTC"""
+    trigger = MagicMock()
+    trigger.expression = "0 9 * * *"
+    trigger.timezone = None
+    trigger.trigger_time = datetime(2025, 10, 4, 9, 0, 0)
+    trigger.graph_name = "test_graph"
+    trigger.namespace = "test_namespace"
+
+    cron_time = datetime(2025, 10, 6, 0, 0, 0)
+
+    with patch('app.tasks.trigger_cron.DatabaseTriggers') as mock_db_class:
+        mock_instance = MagicMock()
+        mock_instance.insert = AsyncMock()
+        mock_db_class.return_value = mock_instance
+
+        await create_next_triggers(trigger, cron_time)
+
+        # Verify None timezone is passed through (will default to UTC in ZoneInfo call)
+        call_kwargs = mock_db_class.call_args[1]
+        assert call_kwargs['timezone'] is None
+
+
+@pytest.mark.asyncio
+async def test_create_next_triggers_with_europe_london_timezone():
+    """Test create_next_triggers with Europe/London timezone"""
+    trigger = MagicMock()
+    trigger.expression = "0 17 * * *"
+    trigger.timezone = "Europe/London"
+    trigger.trigger_time = datetime(2025, 10, 4, 16, 0, 0)  # UTC time
+    trigger.graph_name = "test_graph"
+    trigger.namespace = "test_namespace"
+
+    cron_time = datetime(2025, 10, 6, 0, 0, 0)
+
+    with patch('app.tasks.trigger_cron.DatabaseTriggers') as mock_db_class:
+        mock_instance = MagicMock()
+        mock_instance.insert = AsyncMock()
+        mock_db_class.return_value = mock_instance
+
+        await create_next_triggers(trigger, cron_time)
+
+        # Verify Europe/London timezone was used
+        call_kwargs = mock_db_class.call_args[1]
+        assert call_kwargs['timezone'] == "Europe/London"
+
+
+@pytest.mark.asyncio
+async def test_create_next_triggers_handles_duplicate_key_error():
+    """Test create_next_triggers handles DuplicateKeyError gracefully"""
+    from pymongo.errors import DuplicateKeyError
+
+    trigger = MagicMock()
+    trigger.expression = "0 9 * * *"
+    trigger.timezone = "America/New_York"
+    trigger.trigger_time = datetime(2025, 10, 4, 13, 0, 0)
+    trigger.graph_name = "test_graph"
+    trigger.namespace = "test_namespace"
+
+    cron_time = datetime(2025, 10, 6, 0, 0, 0)
+
+    with patch('app.tasks.trigger_cron.DatabaseTriggers') as mock_db_class:
+        mock_instance = MagicMock()
+        # First call raises DuplicateKeyError, second succeeds
+        mock_instance.insert = AsyncMock(side_effect=[
+            DuplicateKeyError("Duplicate"),
+            None
+        ])
+        mock_db_class.return_value = mock_instance
+
+        with patch('app.tasks.trigger_cron.logger') as mock_logger:
+            # Should not raise exception
+            await create_next_triggers(trigger, cron_time)
+
+            # Verify error was logged
+            assert mock_logger.error.called
+            error_msg = mock_logger.error.call_args[0][0]
+            assert "Duplicate trigger found" in error_msg
+
+
+@pytest.mark.asyncio
+async def test_create_next_triggers_trigger_time_is_datetime():
+    """Test that next trigger_time is a datetime object"""
+    trigger = MagicMock()
+    trigger.expression = "0 9 * * *"
+    trigger.timezone = "America/New_York"
+    trigger.trigger_time = datetime(2025, 10, 4, 13, 0, 0)
+    trigger.graph_name = "test_graph"
+    trigger.namespace = "test_namespace"
+
+    cron_time = datetime(2025, 10, 6, 0, 0, 0)
+
+    with patch('app.tasks.trigger_cron.DatabaseTriggers') as mock_db_class:
+        mock_instance = MagicMock()
+        mock_instance.insert = AsyncMock()
+        mock_db_class.return_value = mock_instance
+
+        await create_next_triggers(trigger, cron_time)
+
+        # Verify trigger_time is a datetime
+        call_kwargs = mock_db_class.call_args[1]
+        assert isinstance(call_kwargs['trigger_time'], datetime)
+
+
+@pytest.mark.asyncio
+async def test_create_next_triggers_creates_multiple_triggers():
+    """Test create_next_triggers creates multiple future triggers"""
+    trigger = MagicMock()
+    trigger.expression = "0 */6 * * *"  # Every 6 hours
+    trigger.timezone = "UTC"
+    trigger.trigger_time = datetime(2025, 10, 4, 0, 0, 0)
+    trigger.graph_name = "test_graph"
+    trigger.namespace = "test_namespace"
+
+    cron_time = datetime(2025, 10, 5, 0, 0, 0)  # 24 hours later
+
+    with patch('app.tasks.trigger_cron.DatabaseTriggers') as mock_db_class:
+        mock_instance = MagicMock()
+        mock_instance.insert = AsyncMock()
+        mock_db_class.return_value = mock_instance
+
+        await create_next_triggers(trigger, cron_time)
+
+        # Should create multiple triggers (every 6 hours until past cron_time)
+        assert mock_db_class.call_count >= 4  # At least 4 triggers in 24 hours