1 files changed, 67 insertions, 0 deletions

diff --git a/spec/services/discussions/capture_diff_note_positions_service_spec.rb b/spec/services/discussions/capture_diff_note_positions_service_spec.rb
new file mode 100644
index 00000000000..7b1e207f3eb
--- /dev/null
+++ b/spec/services/discussions/capture_diff_note_positions_service_spec.rb
@@ -0,0 +1,67 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Discussions::CaptureDiffNotePositionsService do
+  context 'when merge request has a discussion' do
+    let(:source_branch) { 'compare-with-merge-head-source' }
+    let(:target_branch) { 'compare-with-merge-head-target' }
+    let(:merge_request) { create(:merge_request, source_branch: source_branch, target_branch: target_branch) }
+    let(:project) { merge_request.project }
+
+    let(:offset) { 30 }
+    let(:first_new_line) { 508 }
+    let(:second_new_line) { 521 }
+
+    let(:service) { described_class.new(merge_request) }
+
+    def build_position(new_line, diff_refs)
+      path = 'files/markdown/ruby-style-guide.md'
+      Gitlab::Diff::Position.new(old_path: path, new_path: path,
+        new_line: new_line, diff_refs: diff_refs)
+    end
+
+    def note_for(new_line)
+      position = build_position(new_line, merge_request.diff_refs)
+      create(:diff_note_on_merge_request, project: project, position: position, noteable: merge_request)
+    end
+
+    def verify_diff_note_position!(note, line)
+      id, old_line, new_line = note.line_code.split('_')
+
+      expect(new_line).to eq(line.to_s)
+      expect(note.diff_note_positions.size).to eq(1)
+
+      diff_position = note.diff_note_positions.last
+      diff_refs = Gitlab::Diff::DiffRefs.new(
+        base_sha: merge_request.target_branch_sha,
+        start_sha: merge_request.target_branch_sha,
+        head_sha: merge_request.merge_ref_head.sha)
+
+      expect(diff_position.line_code).to eq("#{id}_#{old_line.to_i - offset}_#{new_line}")
+      expect(diff_position.position).to eq(build_position(new_line.to_i, diff_refs))
+    end
+
+    let!(:first_discussion_note) { note_for(first_new_line) }
+    let!(:second_discussion_note) { note_for(second_new_line) }
+    let!(:second_discussion_another_note) do
+      create(:diff_note_on_merge_request,
+        project: project,
+        position: second_discussion_note.position,
+        discussion_id: second_discussion_note.discussion_id,
+        noteable: merge_request)
+    end
+
+    context 'and position of the discussion changed on target branch head' do
+      it 'diff positions are created for the first notes of the discussions' do
+        MergeRequests::MergeToRefService.new(project, merge_request.author).execute(merge_request)
+        service.execute
+
+        verify_diff_note_position!(first_discussion_note, first_new_line)
+        verify_diff_note_position!(second_discussion_note, second_new_line)
+
+        expect(second_discussion_another_note.diff_note_positions).to be_empty
+      end
+    end
+  end
+end