Address review comments from @nilsding

Co-authored-by: nilsding <nilsding@nilsding.org>

app/controllers/ajax/web_push_controller.rb

@@ -22,7 +22,7 @@ class Ajax::WebPushController < AjaxController
     @response[:message] = t(".subscription_count", count: current_user.web_push_subscriptions.count)
   end
 
-  def unsubscribe
+  def unsubscribe # rubocop:disable Metrics/AbcSize
     params.permit(:endpoint)
 
     removed = if params.key?(:endpoint)

app/workers/question_worker.rb

@@ -19,7 +19,7 @@ class QuestionWorker
       next if user.muting?(question.user)
 
       inbox = Inbox.create(user_id: f.id, question_id:, new: true)
-      f.push_notification(webpush_app, inbox)
+      f.push_notification(webpush_app, inbox) if webpush_app
     end
   rescue StandardError => e
     logger.info "failed to ask question: #{e.message}"

config/justask.yml.example

@@ -8,6 +8,8 @@ hostname: "justask.rrerr.net"
 https: true
 
 email_from: "noreply@justask.rrerr.net"
+# Required by WebPush spec in case of problems with notifications
+contact_email: "contact@justask.rrerr.net"
 
 # Name of the "Anonymous" user. (e.g. "Anonymous Coward", "Arno Nym", "Mr. X", ...)
 anonymous_name: "Anonymous"

db/migrate/20220909220449_add_webpush_app.rb

@@ -7,7 +7,7 @@ class AddWebpushApp < ActiveRecord::Migration[6.1]
     vapid_keypair = Webpush.generate_key.to_hash
     app = Rpush::Webpush::App.new
     app.name = "webpush"
-    app.certificate = vapid_keypair.merge(subject: "user@example.com").to_json # TODO: put an email address here
+    app.certificate = vapid_keypair.merge(subject: APP_CONFIG["contact_email"]).to_json
     app.connections = 1
     app.save!
   end

lib/use_case/question/create.rb

@@ -31,7 +31,7 @@ module UseCase
         inbox = ::Inbox.create!(user: target_user, question: question, new: true)
 
         webpush_app = ::Rpush::App.find_by(name: "webpush")
-        target_user.push_notification(webpush_app, inbox)
+        target_user.push_notification(webpush_app, inbox) if webpush_app
 
         {
           status:   201,