Add Discussion model to represent MR/diff discussion

lib/gitlab/diff/parallel_diff.rb

@@ -8,72 +8,35 @@ module Gitlab
       end
       def parallelize
-
         i = 0
         free_right_index = nil
         lines = []
         highlighted_diff_lines = diff_file.highlighted_diff_lines
         highlighted_diff_lines.each do |line|
-          line_code = diff_file.line_code(line)
-          position = diff_file.position(line)
-
-          case line.type
-          when 'match', nil
+          if line.meta? || line.unchanged?
             # line in the right panel is the same as in the left one
             lines << {
-              left: {
-                type:       line.type,
-                number:     line.old_pos,
-                text:       line.text,
-                line_code:  line_code,
-                position:   position
-              },
-              right: {
-                type:       line.type,
-                number:     line.new_pos,
-                text:       line.text,
-                line_code:  line_code,
-                position:   position
-              }
+              left: line,
+              right: line
             }
             free_right_index = nil
             i += 1
-          when 'old'
+          elsif line.removed?
             lines << {
-              left: {
-                type:       line.type,
-                number:     line.old_pos,
-                text:       line.text,
-                line_code:  line_code,
-                position:   position
-              },
-              right: {
-                type:       nil,
-                number:     nil,
-                text:       "",
-                line_code:  line_code,
-                position:   position
-              }
+              left: line,
+              right: nil
             }
             # Once we come upon a new line it can be put on the right of this old line
             free_right_index ||= i
             i += 1
-          when 'new'
-            data = {
-              type:       line.type,
-              number:     line.new_pos,
-              text:       line.text,
-              line_code:  line_code,
-              position:   position
-            }
-
+          elsif line.added?
             if free_right_index
               # If an old line came before this without a line on the right, this
               # line can be put to the right of it.
-              lines[free_right_index][:right] = data
+              lines[free_right_index][:right] = line
               # If there are any other old lines on the left that don't yet have
               # a new counterpart on the right, update the free_right_index
@@ -81,14 +44,8 @@ module Gitlab
               free_right_index = next_free_right_index < i ? next_free_right_index : nil
             else
               lines << {
-                left: {
-                  type:       nil,
-                  number:     nil,
-                  text:       "",
-                  line_code:  line_code,
-                  position:   position
-                },
-                right: data
+                left: nil,
+                right: line
               }
               free_right_index = nil

spec/lib/gitlab/diff/parallel_diff_spec.rb

@@ -11,11 +11,51 @@ describe Gitlab::Diff::ParallelDiff, lib: true do
   let(:diff_file) { Gitlab::Diff::File.new(diff, diff_refs: commit.diff_refs, repository: repository) }
   subject { described_class.new(diff_file) }
-  let(:parallel_diff_result_array) { YAML.load_file("#{Rails.root}/spec/fixtures/parallel_diff_result.yml") }
-
   describe '#parallelize' do
     it 'should return an array of arrays containing the parsed diff' do
-      expect(subject.parallelize).to match_array(parallel_diff_result_array)
+      diff_lines = diff_file.highlighted_diff_lines
+      expected = [
+        # Unchanged lines
+        { left: diff_lines[0], right: diff_lines[0] },
+        { left: diff_lines[1], right: diff_lines[1] },
+        { left: diff_lines[2], right: diff_lines[2] },
+        { left: diff_lines[3], right: diff_lines[3] },
+        { left: diff_lines[4], right: diff_lines[5] },
+        { left: diff_lines[6], right: diff_lines[6] },
+        { left: diff_lines[7], right: diff_lines[7] },
+        { left: diff_lines[8], right: diff_lines[8] },
+
+        # Changed lines
+        { left: diff_lines[9], right: diff_lines[11] },
+        { left: diff_lines[10], right: diff_lines[12] },
+
+        # Added lines
+        { left: nil, right: diff_lines[13] },
+        { left: nil, right: diff_lines[14] },
+        { left: nil, right: diff_lines[15] },
+        { left: nil, right: diff_lines[16] },
+        { left: nil, right: diff_lines[17] },
+        { left: nil, right: diff_lines[18] },
+
+        # Unchanged lines
+        { left: diff_lines[19], right: diff_lines[19] },
+        { left: diff_lines[20], right: diff_lines[20] },
+        { left: diff_lines[21], right: diff_lines[21] },
+        { left: diff_lines[22], right: diff_lines[22] },
+        { left: diff_lines[23], right: diff_lines[23] },
+        { left: diff_lines[24], right: diff_lines[24] },
+        { left: diff_lines[25], right: diff_lines[25] },
+
+        # Added line
+        { left: nil, right: diff_lines[26] },
+
+        # Unchanged lines
+        { left: diff_lines[27], right: diff_lines[27] },
+        { left: diff_lines[28], right: diff_lines[28] },
+        { left: diff_lines[29], right: diff_lines[29] }
+      ]
+
+      expect(subject.parallelize).to eq(expected)
     end
   end
 end