Merge branch 'fix_diff_line_comments' into 'master'

Fix: A diff comment on a change at last line of a file shows as two comments in discussion

Closes #32353

See merge request !11802

1 files changed, 27 insertions, 0 deletions

diff --git a/spec/helpers/diff_helper_spec.rb b/spec/helpers/diff_helper_spec.rb
index 84341a51f2d..a74615e07f9 100644
--- a/spec/helpers/diff_helper_spec.rb
+++ b/spec/helpers/diff_helper_spec.rb
@@ -129,6 +129,33 @@ describe DiffHelper do
     end
   end
 
+  describe '#parallel_diff_discussions' do
+    let(:discussion) { { 'abc_3_3' => 'comment' } }
+    let(:diff_file) { double(line_code: 'abc_3_3') }
+
+    before do
+      helper.instance_variable_set(:@grouped_diff_discussions, discussion)
+    end
+
+    it 'does not put comments on nonewline lines' do
+      left = Gitlab::Diff::Line.new('\\nonewline', 'old-nonewline', 3, 3, 3)
+      right = Gitlab::Diff::Line.new('\\nonewline', 'new-nonewline', 3, 3, 3)
+
+      result = helper.parallel_diff_discussions(left, right, diff_file)
+
+      expect(result).to eq([nil, nil])
+    end
+
+    it 'puts comments on added lines' do
+      left = Gitlab::Diff::Line.new('\\nonewline', 'old-nonewline', 3, 3, 3)
+      right = Gitlab::Diff::Line.new('new line', 'add', 3, 3, 3)
+
+      result = helper.parallel_diff_discussions(left, right, diff_file)
+
+      expect(result).to eq([nil, 'comment'])
+    end
+  end
+
   describe "#diff_match_line" do
     let(:old_pos) { 40 }
     let(:new_pos) { 50 }