fix: add vapid diagnostics

tracker/tests.py

@@ -259,6 +259,34 @@ class PwaTests(TrackerTestCase):
         self.assertContains(response, 'rel="manifest"')
         self.assertContains(response, "serviceWorker.register")
 
+    @override_settings(VAPID_PUBLIC_KEY="", VAPID_PRIVATE_KEY="")
+    def test_the_reminder_card_explains_itself_when_keys_are_missing(self):
+        # It used to hide entirely, which is indistinguishable from a broken page.
+        self.client.force_login(self.user)
+        response = self.client.get(reverse("tracker:today"))
+
+        self.assertContains(response, "Reminders")
+        self.assertContains(response, "Diagnostics")
+        self.assertContains(response, "generate_vapid_keys")
+
+    @override_settings(VAPID_PUBLIC_KEY="BMn-test-public-key")
+    def test_the_diagnostics_report_reminder_times_and_devices(self):
+        self.client.force_login(self.user)
+
+        response = self.client.get(reverse("tracker:today"))
+        self.assertContains(response, "Doses with a reminder time: 0 of 3")
+        self.assertContains(response, "Devices subscribed (this account): 0")
+
+        self.morning.reminder_time = "08:00"
+        self.morning.save()
+        PushSubscription.objects.create(
+            user=self.user, endpoint="https://push.example/a", p256dh="k", auth="s"
+        )
+
+        response = self.client.get(reverse("tracker:today"))
+        self.assertContains(response, "Doses with a reminder time: 1 of 3")
+        self.assertContains(response, "Devices subscribed (this account): 1")
+
     def test_the_manifest_is_valid_json_pointing_at_real_icons(self):
         response = self.client.get(reverse("manifest"))
 

tracker/views.py

@@ -104,7 +104,14 @@ def today(request):
             "next_date": day + timedelta(days=1),
             "chart": build_chart(readings),
             "reading_count": len(readings),
-            # Empty when push is not configured; the page then hides the card.
+            # Empty when push is not configured; the card then says so rather than
+            # vanishing, because a missing card looks like a bug in the page.
             "vapid_public_key": settings.VAPID_PUBLIC_KEY,
+            "doses_with_reminders": ScheduledDose.objects.filter(
+                is_active=True,
+                medication__is_active=True,
+                reminder_time__isnull=False,
+            ).count(),
+            "subscribed_devices": request.user.push_subscriptions.count(),
         },
     )