Make notifications relation polymorphic

app/models/answer.rb

@@ -44,6 +44,6 @@ class Answer < ApplicationRecord
   # rubocop:enable Rails/SkipsModelValidations
 
   def notification_type(*_args)
-    Notifications::QuestionAnswered
+    Notification::QuestionAnswered
   end
 end

app/models/appendable/reaction.rb

@@ -16,6 +16,6 @@ class Appendable::Reaction < Appendable
   # rubocop:enable Rails/SkipsModelValidations
 
   def notification_type(*_args)
-    Notifications::Smiled
+    Notification::Smiled
   end
 end

app/models/comment.rb

@@ -31,6 +31,6 @@ class Comment < ApplicationRecord
   # rubocop:enable Rails/SkipsModelValidations
 
   def notification_type(*_args)
-    Notifications::Commented
+    Notification::Commented
   end
 end

app/models/notification/comment_smiled.rb

@@ -0,0 +1,2 @@
+class Notification::CommentSmiled < Notification
+end

app/models/notification/commented.rb

@@ -0,0 +1,2 @@
+class Notification::Commented < Notification
+end

app/models/notification/question_answered.rb

@@ -0,0 +1,2 @@
+class Notification::QuestionAnswered < Notification
+end

app/models/notification/smiled.rb

@@ -0,0 +1,2 @@
+class Notification::Smiled < Notification
+end

app/models/notification/started_following.rb

@@ -0,0 +1,2 @@
+class Notification::StartedFollowing < Notification
+end

app/models/notifications/comment_smiled.rb

@@ -1,2 +0,0 @@
-class Notifications::CommentSmiled < Notification
-end

app/models/notifications/commented.rb

@@ -1,2 +0,0 @@
-class Notifications::Commented < Notification
-end

app/models/notifications/question_answered.rb

@@ -1,2 +0,0 @@
-class Notifications::QuestionAnswered < Notification
-end

app/models/notifications/smiled.rb

@@ -1,2 +0,0 @@
-class Notifications::Smiled < Notification
-end

app/models/notifications/started_following.rb

@@ -1,2 +0,0 @@
-class Notifications::StartedFollowing < Notification
-end

app/models/relationships/follow.rb

@@ -10,6 +10,6 @@ class Relationships::Follow < Relationship
   end
 
   def notification_type(*_args)
-    Notifications::StartedFollowing
+    Notification::StartedFollowing
   end
 end

db/migrate/20220720190421_add_type_to_notifications.rb

@@ -0,0 +1,22 @@
+# frozen_string_literal: true
+
+class AddTypeToNotifications < ActiveRecord::Migration[6.1]
+  def up
+    add_column :notifications, :type, :string
+
+    execute "UPDATE notifications SET type = 'Notification::Commented' WHERE target_type = 'Comment'"
+    execute "UPDATE notifications SET type = 'Notification::QuestionAnswered' WHERE target_type = 'Answer'"
+    execute "UPDATE notifications SET type = 'Notification::StartedFollowing' WHERE target_type = 'Relationship'"
+    execute <<~SQUIRREL
+      UPDATE notifications
+      SET type = 'Notification::Smiled'
+      WHERE target_type = 'Appendable'
+        AND target_id IN (SELECT id FROM appendables WHERE type = 'Appendable::Reaction' AND parent_type = 'Answer');
+    SQUIRREL
+    execute "UPDATE notifications SET type = 'Notification::CommentSmiled' WHERE type IS NULL"
+  end
+
+  def down
+    remove_column :notifications, :type
+  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: 2022_07_18_214748) do
+ActiveRecord::Schema.define(version: 2022_07_20_190421) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -116,6 +116,7 @@ ActiveRecord::Schema.define(version: 2022_07_18_214748) do
     t.boolean "new"
     t.datetime "created_at"
     t.datetime "updated_at"
+    t.string "type"
     t.index ["new"], name: "index_notifications_on_new"
     t.index ["recipient_id"], name: "index_notifications_on_recipient_id"
   end