Track failures on Web Push subscriptions

app/controllers/settings/push_notifications_controller.rb

@@ -4,6 +4,6 @@ class Settings::PushNotificationsController < ApplicationController
   before_action :authenticate_user!
 
   def index
-    @subscriptions = current_user.web_push_subscriptions
+    @subscriptions = current_user.web_push_subscriptions.active
   end
 end

app/models/user/push_notification_methods.rb

@@ -4,7 +4,7 @@ module User::PushNotificationMethods
   def push_notification(app, resource)
     raise ArgumentError("Resource must respond to `as_push_notification`") unless resource.respond_to? :as_push_notification
 
-    web_push_subscriptions.each do |s|
+    web_push_subscriptions.active.find_each do |s|
       n = Rpush::Webpush::Notification.new
       n.app = app
       n.registration_ids = [s.subscription.symbolize_keys]

app/models/web_push_subscription.rb

@@ -2,4 +2,7 @@
 
 class WebPushSubscription < ApplicationRecord
   belongs_to :user
+
+  scope :active, -> { where(failures: ...3) }
+  scope :failed, -> { where(failures: 3..) }
 end

config/initializers/rpush.rb

@@ -57,8 +57,14 @@ Rpush.reflect do |on|
 
   # Called when notification delivery failed.
   # Call 'error_code' and 'error_description' on the notification for the cause.
-  # on.notification_failed do |notification|
-  # end
+  on.notification_failed do |notification|
+    # See: https://developer.apple.com/documentation/usernotifications/sending_web_push_notifications_in_safari_and_other_browsers#3994594
+    if %i[403 410].include? notification.error_code
+      subscription = WebPushSubscription::where("subscription ->> 'endpoint' = ?", notification.registration_ids.first[:endpoint])
+      subscription.increment :failures
+      subscription.save
+    end
+  end
 
   # Called when the notification delivery failed and only the notification ID
   # is present in memory.

db/migrate/20221226101907_add_failures_to_web_push_subscriptions.rb

@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+class AddFailuresToWebPushSubscriptions < ActiveRecord::Migration[6.1]
+  def change
+    add_column :web_push_subscriptions, :failures, :integer, default: 0
+  end
+end

db/schema.rb

@@ -387,6 +387,7 @@ ActiveRecord::Schema.define(version: 2022_12_27_065923) do
     t.json "subscription"
     t.datetime "created_at", precision: 6, null: false
     t.datetime "updated_at", precision: 6, null: false
+    t.integer "failures", default: 0
     t.index ["user_id"], name: "index_web_push_subscriptions_on_user_id"
   end