#399

backend/app/models/post.rb

@@ -27,6 +27,18 @@ class Post < ApplicationRecord
     upload.rewind
   end
 
+  def self.remote_thumbnail_attachment(raw_url)
+    response = Preview::ThumbnailFetcher.fetch_image_response(raw_url)
+    resized_thumbnail_attachment(StringIO.new(response.body))
+  rescue Preview::UrlSafety::UnsafeUrl,
+         Preview::ThumbnailFetcher::GenerationFailed,
+         Preview::HttpFetcher::FetchFailed,
+         Preview::HttpFetcher::FetchTimeout,
+         Preview::HttpFetcher::ResponseTooLarge,
+         MiniMagick::Error => e
+    raise RemoteThumbnailFetchFailed, e.message
+  end
+
   belongs_to :uploaded_user, class_name: 'User', optional: true
 
   has_many :post_tags, dependent: :destroy, inverse_of: :post
@@ -157,17 +169,7 @@ class Post < ApplicationRecord
   end
 
   def attach_thumbnail_from_url! raw_url
-    response = Preview::ThumbnailFetcher.fetch_image_response(raw_url)
-    thumbnail.attach(
-        self.class.resized_thumbnail_attachment(
-            StringIO.new(response.body)))
-  rescue Preview::UrlSafety::UnsafeUrl,
-         Preview::ThumbnailFetcher::GenerationFailed,
-         Preview::HttpFetcher::FetchFailed,
-         Preview::HttpFetcher::FetchTimeout,
-         Preview::HttpFetcher::ResponseTooLarge,
-         MiniMagick::Error => e
-    raise RemoteThumbnailFetchFailed, e.message
+    thumbnail.attach(self.class.remote_thumbnail_attachment(raw_url))
   end
 
   private