Show a message when the calendar has no events.

Closes #34. Upcoming and Past tabs explain an empty list instead of leaving the content area blank.

schasite/tests.py

@@ -66,6 +66,13 @@ class PublicPageTests(TestCase):
         response = self.client.get(reverse("calendar2"))
         self.assertEqual(response.status_code, 200)
 
+    def test_calendar_shows_empty_state_when_no_events(self):
+        response = self.client.get(reverse("calendar2"))
+
+        self.assertEqual(response.status_code, 200)
+        self.assertContains(response, "There are no upcoming events to display.")
+        self.assertContains(response, "There are no past events to display.")
+
     def test_newsletters_renders(self):
         response = self.client.get(reverse("newsletters2"))
         self.assertEqual(response.status_code, 200)
@@ -414,6 +421,8 @@ class CalendarEventTests(TestCase):
         self.assertNotIn("Ongoing Event", past_html)
         self.assertIn("Archived Picnic", past_html)
         self.assertNotIn("Archived Picnic", upcoming_html)
+        self.assertNotIn("There are no upcoming events to display.", upcoming_html)
+        self.assertNotIn("There are no past events to display.", past_html)
 
 
 @override_settings(