#398

backend/app/controllers/preview_controller.rb

@@ -6,7 +6,7 @@ class PreviewController < ApplicationController
 
     render json: { title: Preview::ThumbnailFetcher.title(params[:url]) }
   rescue Preview::UrlSafety::UnsafeUrl => e
-    render_preview_error(e.message, :unprocessable_entity)
+    render_bad_request(e.message)
   rescue Preview::HttpFetcher::FetchTimeout => e
     render_preview_error(e.message, :gateway_timeout)
   rescue Preview::HttpFetcher::FetchFailed => e
@@ -20,17 +20,18 @@ class PreviewController < ApplicationController
     image.auto_orient
     image.resize '180x180>'
     image.format 'png'
+    width, height = image.dimensions
+    raise Preview::ThumbnailFetcher::GenerationFailed, 'サムネール画像の変換に失敗しました．' if width > 180 || height > 180
+
     send_data image.to_blob, type: 'image/png', disposition: 'inline'
   rescue Preview::UrlSafety::UnsafeUrl => e
-    render_preview_error(e.message, :unprocessable_entity)
-  rescue Preview::Screenshot::Busy => e
-    render_preview_error(e.message, :too_many_requests)
-  rescue Preview::Screenshot::TimedOut, Preview::HttpFetcher::FetchTimeout => e
+    render_bad_request(e.message)
+  rescue Preview::HttpFetcher::FetchTimeout => e
     render_preview_error(e.message, :gateway_timeout)
   rescue Preview::HttpFetcher::FetchFailed => e
     render_preview_error(e.message, :bad_gateway)
-  rescue Preview::Screenshot::Unavailable, MiniMagick::Error => e
-    render_preview_error(e.message, :unprocessable_entity)
+  rescue Preview::ThumbnailFetcher::GenerationFailed, MiniMagick::Error => e
+    render_unprocessable_entity(e.message)
   end
 
   private