FIX: Delete invalid web push subscriptions (#12447)

The endpoint as well as the public and private ECDH keys are required to successfully send a push notification.

app/services/push_notification_pusher.rb

@@ -77,12 +77,21 @@ class PushNotificationPusher
   end
 
   def self.send_notification(user, subscription, message)
+    endpoint = subscription["endpoint"]
+    p256dh = subscription.dig("keys", "p256dh")
+    auth = subscription.dig("keys", "auth")
+
+    if (endpoint.blank? || p256dh.blank? || auth.blank?)
+      unsubscribe(user, subscription)
+      return
+    end
+
     begin
       Webpush.payload_send(
-        endpoint: subscription["endpoint"],
+        endpoint: endpoint,
         message: message.to_json,
-        p256dh: subscription.dig("keys", "p256dh"),
-        auth: subscription.dig("keys", "auth"),
+        p256dh: p256dh,
+        auth: auth,
         vapid: {
           subject: Discourse.base_url,
           public_key: SiteSetting.vapid_public_key,

spec/services/push_notification_pusher_spec.rb

@@ -42,4 +42,33 @@ RSpec.describe PushNotificationPusher do
     })
   end
 
+  it "deletes invalid subscriptions during send" do
+    user = Fabricate(:walter_white)
+
+    missing_endpoint = PushSubscription.create!(user_id: user.id, data:
+      { p256dh: "public ECDH key", keys: { auth: "private ECDH key" } }.to_json)
+
+    missing_p256dh = PushSubscription.create!(user_id: user.id, data:
+      { endpoint: "endpoint 1", keys: { auth: "private ECDH key" } }.to_json)
+
+    missing_auth = PushSubscription.create!(user_id: user.id, data:
+      { endpoint: "endpoint 2", keys: { p256dh: "public ECDH key" } }.to_json)
+
+    valid_subscription = PushSubscription.create!(user_id: user.id, data:
+      { endpoint: "endpoint 3", keys: { p256dh: "public ECDH key", auth: "private ECDH key" } }.to_json)
+
+    expect(PushSubscription.where(user_id: user.id)).to contain_exactly(missing_endpoint, missing_p256dh, missing_auth, valid_subscription)
+    Webpush.expects(:payload_send).with(has_entries(endpoint: "endpoint 3", p256dh: "public ECDH key", auth: "private ECDH key")).once
+
+    PushNotificationPusher.push(user, {
+      topic_title: 'Topic',
+      username: 'system',
+      excerpt: 'description',
+      topic_id: 1,
+      post_url: "https://example.com/t/1/2",
+      notification_type: 1
+    })
+
+    expect(PushSubscription.where(user_id: user.id)).to contain_exactly(valid_subscription)
+  end
 end