Merge remote-tracking branch 'origin/main' into feature/351

backend/app/models/post.rb

@@ -1,5 +1,19 @@
 class Post < ApplicationRecord
   require 'mini_magick'
+  require 'stringio'
+
+  def self.resized_thumbnail_attachment(upload)
+    upload.rewind
+    image = MiniMagick::Image.read(upload.read)
+    image.resize '180x180'
+    image.format 'jpg'
+
+    { io: StringIO.new(image.to_blob),
+      filename: 'resized_thumbnail.jpg',
+      content_type: 'image/jpeg' }
+  ensure
+    upload.rewind
+  end
 
   belongs_to :uploaded_user, class_name: 'User', optional: true
 
@@ -123,12 +137,7 @@ class Post < ApplicationRecord
   def resized_thumbnail!
     return unless thumbnail.attached?
 
-    image = MiniMagick::Image.read(thumbnail.download)
-    image.resize '180x180'
-    thumbnail.purge
-    thumbnail.attach(io:            File.open(image.path),
-                     filename:      'resized_thumbnail.jpg',
-                     content_type:  'image/jpeg')
+    thumbnail.attach(self.class.resized_thumbnail_attachment(StringIO.new(thumbnail.download)))
   end
 
   private