Fix inline rendering of videos

Fix VideoLinkFilter to handle uppercase file extesions

changelogs/unreleased/29284-video-preview-not-working.yml

+---
+title: Fix inline rendering of videos for uploads with uppercase file extensions
+merge_request: 17581
+author:
+type: fixed

lib/banzai/filter/video_link_filter.rb

@@ -8,8 +8,8 @@ module Banzai
     # a "Download" link in the case the video cannot be played.
     class VideoLinkFilter < HTML::Pipeline::Filter
       def call
-        doc.xpath(query).each do |el|
-          el.replace(video_node(doc, el))
+        doc.xpath('descendant-or-self::img[not(ancestor::a)]').each do |el|
+          el.replace(video_node(doc, el)) if has_video_extension?(el)
         end
 
         doc
@@ -17,22 +17,10 @@ module Banzai
 
       private
 
-      def query
-        @query ||= begin
-          src_query = UploaderHelper::SAFE_VIDEO_EXT.map do |ext|
-            "'.#{ext}' = substring(@src, string-length(@src) - #{ext.size})"
-          end
-
-          if context[:asset_proxy_enabled].present?
-            src_query.concat(
-              UploaderHelper::SAFE_VIDEO_EXT.map do |ext|
-                "'.#{ext}' = substring(@data-canonical-src, string-length(@data-canonical-src) - #{ext.size})"
-              end
-            )
-          end
+      def has_video_extension?(element)
+        src_attr = context[:asset_proxy_enabled] ? 'data-canonical-src' : 'src'
 
-          "descendant-or-self::img[not(ancestor::a) and (#{src_query.join(' or ')})]"
-        end
+        element.attr(src_attr).downcase.end_with?(*UploaderHelper::SAFE_VIDEO_EXT)
       end
 
       def video_node(doc, element)

spec/lib/banzai/filter/video_link_filter_spec.rb

@@ -17,8 +17,7 @@ describe Banzai::Filter::VideoLinkFilter do
 
   let(:project) { create(:project, :repository) }
 
-  context 'when the element src has a video extension' do
-    UploaderHelper::SAFE_VIDEO_EXT.each do |ext|
+  shared_examples 'replaces the image tag with a video tag' do |ext|
     it "replaces the image tag 'path/video.#{ext}' with a video tag" do
       container = filter(link_to_image("/path/video.#{ext}")).children.first
 
@@ -39,6 +38,12 @@ describe Banzai::Filter::VideoLinkFilter do
       expect(link['target']).to eq '_blank'
     end
   end
+
+  context 'when the element src has a video extension' do
+    UploaderHelper::SAFE_VIDEO_EXT.each do |ext|
+      it_behaves_like 'replaces the image tag with a video tag', ext
+      it_behaves_like 'replaces the image tag with a video tag', ext.upcase
+    end
   end
 
   context 'when the element src is an image' do