1 files changed, 43 insertions, 0 deletions
diff --git a/lib/gitlab/diff/file_collection_sorter.rb b/lib/gitlab/diff/file_collection_sorter.rb
new file mode 100644
index 00000000000..94626875580
--- /dev/null
+++ b/lib/gitlab/diff/file_collection_sorter.rb
@@ -0,0 +1,43 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module Diff
+    class FileCollectionSorter
+      attr_reader :diffs
+
+      def initialize(diffs)
+        @diffs = diffs
+      end
+
+      def sort
+        diffs.sort do |a, b|
+          compare_path_parts(path_parts(a), path_parts(b))
+        end
+      end
+
+      private
+
+      def path_parts(diff)
+        (diff.new_path.presence || diff.old_path).split(::File::SEPARATOR)
+      end
+
+      # Used for sorting the file paths by:
+      # 1. Directory name
+      # 2. Depth
+      # 3. File name
+      def compare_path_parts(a_parts, b_parts)
+        a_part = a_parts.shift
+        b_part = b_parts.shift
+
+        return 1 if a_parts.size < b_parts.size && a_parts.empty?
+        return -1 if a_parts.size > b_parts.size && b_parts.empty?
+
+        comparison = a_part <=> b_part
+
+        return comparison unless comparison == 0
+
+        compare_path_parts(a_parts, b_parts)
+      end
+    end
+  end
+end