Allow push notifications via Expo

app/controllers/api/v1/push/subscriptions_controller.rb

@@ -13,6 +13,7 @@ def create
       endpoint: subscription_params[:endpoint],
       key_p256dh: subscription_params[:keys][:p256dh],
       key_auth: subscription_params[:keys][:auth],
+      expo: subscription_params[:expo],
       data: data_params,
       user_id: current_user.id,
       access_token_id: doorkeeper_token.id
@@ -46,7 +47,7 @@ def check_push_subscription
   end
 
   def subscription_params
-    params.require(:subscription).permit(:endpoint, keys: [:auth, :p256dh])
+    params.require(:subscription).permit(:endpoint, :expo, keys: [:auth, :p256dh])
   end
 
   def data_params

app/models/web/push_subscription.rb

@@ -5,13 +5,14 @@
 #
 #  id              :bigint(8)        not null, primary key
 #  endpoint        :string           not null
-#  key_p256dh      :string           not null
-#  key_auth        :string           not null
+#  key_p256dh      :string
+#  key_auth        :string
 #  data            :json
 #  created_at      :datetime         not null
 #  updated_at      :datetime         not null
 #  access_token_id :bigint(8)
 #  user_id         :bigint(8)
+#  expo            :string
 #
 
 class Web::PushSubscription < ApplicationRecord
@@ -21,8 +22,8 @@ class Web::PushSubscription < ApplicationRecord
   has_one :session_activation, foreign_key: 'web_push_subscription_id', inverse_of: :web_push_subscription
 
   validates :endpoint, presence: true
-  validates :key_p256dh, presence: true
-  validates :key_auth, presence: true
+  validates :key_p256dh, presence: true, unless: :expo?
+  validates :key_auth, presence: true, unless: :expo?
 
   delegate :locale, to: :associated_user
 

app/workers/web/push_notification_worker.rb

@@ -16,8 +16,10 @@ def perform(subscription_id, notification_id)
     # in the meantime, so we have to double-check before proceeding
     return unless @notification.activity.present? && @subscription.pushable?(@notification)
 
-    payload = @subscription.encrypt(push_notification_json)
+    return expo_send if @subscription.expo?
 
+    payload = @subscription.encrypt(push_notification_json)
+
     request_pool.with(@subscription.audience) do |http_client|
       request = Request.new(:post, @subscription.endpoint, body: payload.fetch(:ciphertext), http_client: http_client)
 
@@ -38,7 +40,7 @@ def perform(subscription_id, notification_id)
         # and must be removed
 
         if (400..499).cover?(response.code) && ![408, 429].include?(response.code)
-          @subscription.destroy!
+          raise Mastodon::UnexpectedResponseError, response
         elsif !(200...300).cover?(response.code)
           raise Mastodon::UnexpectedResponseError, response
         end
@@ -50,6 +52,29 @@ def perform(subscription_id, notification_id)
 
   private
 
+  def expo_send
+    request_pool.with(@subscription.audience) do |http_client|
+      body = push_notification_json
+
+      request = Request.new(:post, @subscription.endpoint, body: body, http_client: http_client)
+
+      request.add_headers(
+        'Content-Type'     => 'application/json',
+        'Accept' => 'application/json',
+        'Accept-Encoding' => 'gzip, deflate',
+        'Host' => 'exp.host',
+        'Ttl'              => TTL,
+        'Urgency'          => URGENCY,
+      )
+
+      request.perform do |response|
+        if !(200...300).cover?(response.code)
+          raise Mastodon::UnexpectedResponseError, response
+        end
+      end
+    end
+  end
+
   def push_notification_json
     json = I18n.with_locale(@subscription.locale || I18n.default_locale) do
       ActiveModelSerializers::SerializableResource.new(
@@ -60,6 +85,15 @@ def push_notification_json
       ).as_json
     end
 
+    if (@subscription.expo?)
+      json.delete :access_token
+      json.delete :preferred_locale
+      json.delete :notification_id
+      json.delete :notification_type
+
+      json[:to] = @subscription.expo
+    end
+
     Oj.dump(json)
   end
 

db/migrate/20210708211904_add_expo_to_web_push_subscriptions.rb

@@ -0,0 +1,20 @@
+class AddExpoToWebPushSubscriptions < ActiveRecord::Migration[6.1]
+  def up
+    safety_assured do
+      change_table(:web_push_subscriptions) do |t|
+        t.column :expo, :string
+        t.change :key_p256dh, :string, null: true
+        t.change :key_auth, :string, null: true
+      end
+    end
+  end
+  def down
+    safety_assured do
+      change_table(:web_push_subscriptions) do |t|
+        t.remove :expo
+        t.change :key_p256dh, :string, null: false
+        t.change :key_auth, :string, null: false
+      end
+    end
+  end
+end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 2021_06_09_202149) do
+ActiveRecord::Schema.define(version: 2021_07_08_211904) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -937,13 +937,14 @@
 
   create_table "web_push_subscriptions", force: :cascade do |t|
     t.string "endpoint", null: false
-    t.string "key_p256dh", null: false
-    t.string "key_auth", null: false
+    t.string "key_p256dh"
+    t.string "key_auth"
     t.json "data"
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
     t.bigint "access_token_id"
     t.bigint "user_id"
+    t.string "expo"
     t.index ["access_token_id"], name: "index_web_push_subscriptions_on_access_token_id"
     t.index ["user_id"], name: "index_web_push_subscriptions_on_user_id"
   end

spec/controllers/api/v1/push/subscriptions_controller_spec.rb

@@ -20,6 +20,7 @@
           p256dh: 'BEm_a0bdPDhf0SOsrnB2-ategf1hHoCnpXgQsFj5JCkcoMrMt2WHoPfEYOYPzOIs9mZE8ZUaD7VA5vouy0kEkr8=',
           auth: 'eH_C8rq2raXqlcBVDa1gLg==',
         },
+        expo: 'token1234'
       }
     }.with_indifferent_access
   end
@@ -53,6 +54,7 @@
       expect(push_subscription.endpoint).to eq(create_payload[:subscription][:endpoint])
       expect(push_subscription.key_p256dh).to eq(create_payload[:subscription][:keys][:p256dh])
       expect(push_subscription.key_auth).to eq(create_payload[:subscription][:keys][:auth])
+      expect(push_subscription.expo).to eq(create_payload[:subscription][:expo])
       expect(push_subscription.user_id).to eq user.id
       expect(push_subscription.access_token_id).to eq token.id
     end

spec/workers/web/push_notification_worker_spec.rb

@@ -29,11 +29,11 @@
       allow(JWT).to receive(:encode).and_return('jwt.encoded.payload')
 
       stub_request(:post, endpoint).to_return(status: 201, body: '')
-
-      subject.perform(subscription.id, notification.id)
     end
 
     it 'calls the relevant service with the correct headers' do
+      subject.perform(subscription.id, notification.id)
+
       expect(a_request(:post, endpoint).with(headers: {
         'Content-Encoding' => 'aesgcm',
         'Content-Type' => 'application/octet-stream',
@@ -44,5 +44,20 @@
         'Authorization' => 'WebPush jwt.encoded.payload',
       }, body: "+\xB8\xDBT}\u0013\xB6\xDD.\xF9\xB0\xA7\xC8Ҁ\xFD\x99#\xF7\xAC\x83\xA4\xDB,\u001F\xB5\xB9w\x85>\xF7\xADr")).to have_been_made
     end
+
+    it 'calls the relevant service with the correct headers and body when it is an expo subscription' do
+      allow_any_instance_of(subscription.class).to receive(:expo?).and_return(true)
+      allow_any_instance_of(subscription.class).to receive(:expo).and_return('ExpoToken1234')
+      subject.perform(subscription.id, notification.id)
+
+      expect(a_request(:post, endpoint).with(headers: {
+        'Content-Type' => 'application/json',
+        'Accept' => 'application/json',
+        'Accept-Encoding' => 'gzip, deflate',
+        'Host' => 'exp.host',
+        'Ttl' => '172800',
+        'Urgency' => 'normal',
+      }, body: { to: 'ExpoToken1234', title: be_an_instance_of(String), body: be_an_instance_of(String), icon: be_an_instance_of(String)})).to have_been_made
+    end
   end
 end