Added unique index to notifications #2124 (#2213)

* Added unique index to notifications #2124

* Fix migration + add index to schema.rb

* Shoulda matcher notification unique validation

app/models/notification.rb

@@ -8,7 +8,7 @@ class Notification < ApplicationRecord
 
   before_create :mark_notified_at_time
 
-  validates :user_id, uniqueness: { scope: %i[notifiable_id notifiable_type action] }
+  validates :user_id, uniqueness: { scope: %i[organization_id notifiable_id notifiable_type action] }
 
   class << self
     def send_new_follower_notification(follow, is_read = false)

app/services/notifications/new_follower/send.rb

@@ -37,7 +37,7 @@ module Notifications
           notification = Notification.find_by(notification_params)&.destroy
         else
           json_data = { user: user_data(follower), aggregated_siblings: aggregated_siblings }
-          notification = Notification.find_or_create_by(notification_params)
+          notification = Notification.find_or_initialize_by(notification_params)
           notification.notifiable_id = recent_follows.first.id
           notification.notifiable_type = "Follow"
           notification.json_data = json_data

db/migrate/20190326085046_add_unique_index_to_notifications.rb

@@ -0,0 +1,5 @@
+class AddUniqueIndexToNotifications < ActiveRecord::Migration[5.1]
+  def change
+    add_index :notifications, %i[user_id organization_id notifiable_id notifiable_type action], unique: true, name: "index_notifications_on_user_organization_notifiable_and_action"
+  end
+end

db/schema.rb

@@ -515,6 +515,7 @@ ActiveRecord::Schema.define(version: 2019_04_30_123156) do
     t.index ["json_data"], name: "index_notifications_on_json_data", using: :gin
     t.index ["notifiable_id"], name: "index_notifications_on_notifiable_id"
     t.index ["notifiable_type"], name: "index_notifications_on_notifiable_type"
+    t.index ["user_id", "organization_id", "notifiable_id", "notifiable_type", "action"], name: "index_notifications_on_user_organization_notifiable_and_action", unique: true
     t.index ["user_id"], name: "index_notifications_on_user_id"
   end
 

spec/models/notification_spec.rb

@@ -9,6 +9,8 @@ RSpec.describe Notification, type: :model do
   let(:follow_instance) { user.follow(user2) }
   let(:badge_achievement) { create(:badge_achievement) }
 
+  it { is_expected.to validate_uniqueness_of(:user_id).scoped_to(%i[organization_id notifiable_id notifiable_type action]) }
+
   describe "when trying to #send_new_follower_notification after following a tag" do
     let(:tag) { create(:tag) }
     let(:tag_follow) { user.follow(tag) }