Implement suggestion diff lines parser

1 files changed, 37 insertions, 0 deletions

diff --git a/lib/gitlab/diff/suggestion_diff.rb b/lib/gitlab/diff/suggestion_diff.rb
new file mode 100644
index 00000000000..ee153c226b7
--- /dev/null
+++ b/lib/gitlab/diff/suggestion_diff.rb
@@ -0,0 +1,37 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module Diff
+    class SuggestionDiff
+      include Gitlab::Utils::StrongMemoize
+
+      delegate :from_content, :to_content, :from_line, to: :@suggestible
+
+      def initialize(suggestible)
+        @suggestible = suggestible
+      end
+
+      def diff_lines
+        Gitlab::Diff::Parser.new.parse(raw_diff.each_line).to_a
+      end
+
+      private
+
+      def raw_diff
+        "#{diff_header}\n#{from_content_as_diff}#{to_content_as_diff}"
+      end
+
+      def diff_header
+        "@@ -#{from_line} +#{from_line}"
+      end
+
+      def from_content_as_diff
+        from_content.lines.map { |line| line.prepend('-') }.join
+      end
+
+      def to_content_as_diff
+        to_content.lines.map { |line| line.prepend('+') }.join
+      end
+    end
+  end
+end