Allow diff_files to return undecorated files

lib/gitlab/diff/file_collection/merge_request_diff_base.rb

@@ -16,13 +16,13 @@ module Gitlab
             fallback_diff_refs: merge_request_diff.fallback_diff_refs)
         end
 
-        def diff_files
-          strong_memoize(:diff_files) do
-            diff_files = super
-
-            diff_files.each { |diff_file| cache.decorate(diff_file) }
-
-            diff_files
+        def diff_files(decorate_diff_files: true)
+          if decorate_diff_files
+            decorated_diff_files
+          else
+            strong_memoize(:undecorated_diff_files) do
+              super()
+            end
           end
         end
 
@@ -46,6 +46,16 @@ module Gitlab
 
         private
 
+        def decorated_diff_files
+          strong_memoize(:diff_files) do
+            diff_files = diff_files(decorate_diff_files: false)
+
+            diff_files.each { |diff_file| cache.decorate(diff_file) }
+
+            diff_files
+          end
+        end
+
         def cache
           @cache ||= if Feature.enabled?(:hset_redis_diff_caching, project)
                        Gitlab::Diff::HighlightCache.new(self)

lib/gitlab/diff/highlight_cache.rb

@@ -68,12 +68,17 @@ module Gitlab
         end
       end
 
+<<<<<<< HEAD
       def cacheable_files
         strong_memoize(:cacheable_files) do
           diff_files = @diff_collection.diff_files
 
           diff_files.select { |file| cacheable?(file) && read_file(file).nil? }
         end
+=======
+      def uncached_files
+        diff_files.select { |file| read_cache[file.file_path].nil? }
+>>>>>>> Allow diff_files to return undecorated files
       end
 
       # Given a hash of:
@@ -112,10 +117,9 @@ module Gitlab
         deprecated_cache.clear
       end
 
-      #
       def file_paths
         strong_memoize(:file_paths) do
-          @diff_collection.diffs.collect(&:file_path)
+          diff_files.collect(&:file_path)
         end
       end
 
@@ -146,6 +150,12 @@ module Gitlab
       def cacheable?(diff_file)
         diffable.present? && diff_file.text? && diff_file.diffable?
       end
+
+      def diff_files
+        strong_memoize(:diff_files) do
+          @diff_collection.diff_files(decorate_diff_files: true)
+        end
+      end
     end
   end
 end

spec/lib/gitlab/diff/file_collection/merge_request_diff_spec.rb

@@ -9,6 +9,14 @@ describe Gitlab::Diff::FileCollection::MergeRequestDiff do
   let(:diff_files) { subject.diff_files }
 
   describe '#diff_files' do
+    context 'when decorate_diff_files is false' do
+      it 'should not attempt to decorate diff files' do
+        expect(subject.send(:cache)).not_to receive(:decorate)
+
+        subject.diff_files(decorate_diff_files: false)
+      end
+    end
+
     it 'does not highlight binary files' do
       allow_next_instance_of(Gitlab::Diff::File) do |instance|
         allow(instance).to receive(:text?).and_return(false)