#399

backend/app/services/preview/thumbnail_fetcher.rb

@@ -1,9 +1,13 @@
 module Preview
   class ThumbnailFetcher
     class GenerationFailed < StandardError; end
-    ALLOWED_IMAGE_CONTENT_TYPES = [
+    RASTER_IMAGE_CONTENT_TYPES = [
       'image/jpeg', 'image/png', 'image/gif', 'image/webp'
     ].freeze
+    REMOTE_IMAGE_CONTENT_TYPES = [
+      *RASTER_IMAGE_CONTENT_TYPES,
+      'image/svg+xml'
+    ].freeze
     HTML_MAX_BYTES = 1.megabyte
     NICONICO_XML_MAX_BYTES = 256.kilobytes
 
@@ -28,7 +32,7 @@ module Preview
     def self.fetch_image_response(raw_url)
       uri, = UrlSafety.validate(raw_url)
       response = HttpFetcher.fetch(uri.to_s)
-      unless allowed_image_content_type?(response.content_type)
+      unless allowed_remote_image_content_type?(response.content_type)
         raise GenerationFailed, 'サムネール画像が見つかりませんでした．'
       end
 
@@ -51,7 +55,7 @@ module Preview
       return nil if url.blank?
 
       response = HttpFetcher.fetch(url)
-      return nil unless allowed_image_content_type?(response.content_type)
+      return nil unless allowed_remote_image_content_type?(response.content_type)
 
       response.body
     rescue HttpFetcher::FetchTimeout
@@ -92,13 +96,13 @@ module Preview
       nil
     end
 
-    def self.allowed_image_content_type?(content_type)
+    def self.allowed_remote_image_content_type?(content_type)
       mime_type = content_type.to_s.split(';', 2).first.downcase.strip
-      ALLOWED_IMAGE_CONTENT_TYPES.include?(mime_type)
+      REMOTE_IMAGE_CONTENT_TYPES.include?(mime_type)
     end
 
     private_class_method :fetch_image_or_nil, :fetch_image!,
                          :niconico_thumbnail_url,
-                         :allowed_image_content_type?
+                         :allowed_remote_image_content_type?
   end
 end