Testing improvement for data model usage

[aduane]

Tests covering methods which utilize Django ORM queries must include assertions about the difference in behavior when the filters are adjusted. If a method accepts a patient_id, and uses that value to look up data belonging to that patient, a negative test should show that the same data is not returned given a different patient_id.

Example bad test:

class TestLastVisit:
    """Test last visit retrieval."""

    @patch("provider_panel_dashboard.apps.dashboard.Appointment")
    @patch("provider_panel_dashboard.apps.dashboard.arrow")
    def test_get_last_visit_with_appointment(self, mock_arrow, mock_appointment_class, dashboard_app):
        """Test retrieving last completed appointment."""
        # Mock current time
        mock_now = Mock()
        mock_now.datetime = datetime(2025, 12, 16, 12, 0, 0)
        mock_arrow.now.return_value = mock_now

        # Create mock appointment
        mock_appointment = Mock()
        mock_appointment.start_time = datetime(2025, 12, 1, 10, 0, 0)

        # Mock the query chain
        mock_queryset = Mock()
        mock_queryset.__iter__ = Mock(return_value=iter([mock_appointment]))
        mock_queryset.__getitem__ = Mock(return_value=mock_appointment)
        mock_queryset.__bool__ = Mock(return_value=True)

        mock_appointment_class.objects.filter.return_value.order_by.return_value = mock_queryset

        last_visit = dashboard_app._get_last_visit("patient-123")

        assert last_visit["found"] is True
        assert last_visit["date"] == "12/01/2025"
        assert last_visit["datetime"] == datetime(2025, 12, 1, 10, 0, 0)

This test would not fail if the method it was testing neglected to use the patient_id it was called with. It should also be asserting that only the most recent appointment is returned by asserting that the queryset's order_by method was called once with "start_time" as a parameter.