Merge branch '41492-mr-comment-fix' into 'master'

Fix links to old commits in merge request comments

Closes #41492

See merge request gitlab-org/gitlab-ce!16152

(cherry picked from commit cdda83ebe9c5e85074d1bd2d718ab84afc672e17)

c1ea4afa Fix links to old commits in merge requests

2 files changed, 66 insertions, 14 deletions

diff --git a/spec/models/diff_discussion_spec.rb b/spec/models/diff_discussion_spec.rb
index fa02434b0fd..50b19000799 100644
--- a/spec/models/diff_discussion_spec.rb
+++ b/spec/models/diff_discussion_spec.rb
@@ -47,8 +47,20 @@ describe DiffDiscussion do
         diff_note.save!
       end
 
-      it 'returns the diff ID for the version to show' do
-        expect(subject.merge_request_version_params).to eq(diff_id: merge_request_diff1.id)
+      context 'when commit_id is not present' do
+        it 'returns the diff ID for the version to show' do
+          expect(subject.merge_request_version_params).to eq(diff_id: merge_request_diff1.id)
+        end
+      end
+
+      context 'when commit_id is present' do
+        before do
+          diff_note.update_attribute(:commit_id, 'commit_123')
+        end
+
+        it 'includes the commit_id in the result' do
+          expect(subject.merge_request_version_params).to eq(diff_id: merge_request_diff1.id, commit_id: 'commit_123')
+        end
       end
     end
 
@@ -70,8 +82,20 @@ describe DiffDiscussion do
         diff_note.save!
       end
 
-      it 'returns the diff ID and start sha of the versions to compare' do
-        expect(subject.merge_request_version_params).to eq(diff_id: merge_request_diff3.id, start_sha: merge_request_diff1.head_commit_sha)
+      context 'when commit_id is not present' do
+        it 'returns the diff ID and start sha of the versions to compare' do
+          expect(subject.merge_request_version_params).to eq(diff_id: merge_request_diff3.id, start_sha: merge_request_diff1.head_commit_sha)
+        end
+      end
+
+      context 'when commit_id is present' do
+        before do
+          diff_note.update_attribute(:commit_id, 'commit_123')
+        end
+
+        it 'includes the commit_id in the result' do
+          expect(subject.merge_request_version_params).to eq(diff_id: merge_request_diff3.id, start_sha: merge_request_diff1.head_commit_sha, commit_id: 'commit_123')
+        end
       end
     end
 
@@ -83,8 +107,20 @@ describe DiffDiscussion do
         diff_note.save!
       end
 
-      it 'returns nil' do
-        expect(subject.merge_request_version_params).to be_nil
+      context 'when commit_id is not present' do
+        it 'returns empty hash' do
+          expect(subject.merge_request_version_params).to eq(nil)
+        end
+      end
+
+      context 'when commit_id is present' do
+        before do
+          diff_note.update_attribute(:commit_id, 'commit_123')
+        end
+
+        it 'returns the commit_id' do
+          expect(subject.merge_request_version_params).to eq(commit_id: 'commit_123')
+        end
       end
     end
   end
diff --git a/spec/services/system_note_service_spec.rb b/spec/services/system_note_service_spec.rb
index 47412110b4b..17f4136c2b0 100644
--- a/spec/services/system_note_service_spec.rb
+++ b/spec/services/system_note_service_spec.rb
@@ -2,6 +2,7 @@ require 'spec_helper'
 
 describe SystemNoteService do
   include Gitlab::Routing
+  include RepoHelpers
 
   set(:group)    { create(:group) }
   set(:project)  { create(:project, :repository, group: group) }
@@ -1070,17 +1071,32 @@ describe SystemNoteService do
       let(:action)            { 'outdated' }
     end
 
-    it 'creates a new note in the discussion' do
-      # we need to completely rebuild the merge request object, or the `@discussions` on the merge request are not reloaded.
-      expect { subject }.to change { reloaded_merge_request.discussions.first.notes.size }.by(1)
+    context 'when the change_position is valid for the discussion' do
+      it 'creates a new note in the discussion' do
+        # we need to completely rebuild the merge request object, or the `@discussions` on the merge request are not reloaded.
+        expect { subject }.to change { reloaded_merge_request.discussions.first.notes.size }.by(1)
+      end
+
+      it 'links to the diff in the system note' do
+        expect(subject.note).to include('version 1')
+
+        diff_id = merge_request.merge_request_diff.id
+        line_code = change_position.line_code(project.repository)
+        expect(subject.note).to include(diffs_project_merge_request_url(project, merge_request, diff_id: diff_id, anchor: line_code))
+      end
     end
 
-    it 'links to the diff in the system note' do
-      expect(subject.note).to include('version 1')
+    context 'when the change_position is invalid for the discussion' do
+      let(:change_position) { project.commit(sample_commit.id) }
 
-      diff_id = merge_request.merge_request_diff.id
-      line_code = change_position.line_code(project.repository)
-      expect(subject.note).to include(diffs_project_merge_request_url(project, merge_request, diff_id: diff_id, anchor: line_code))
+      it 'creates a new note in the discussion' do
+        # we need to completely rebuild the merge request object, or the `@discussions` on the merge request are not reloaded.
+        expect { subject }.to change { reloaded_merge_request.discussions.first.notes.size }.by(1)
+      end
+
+      it 'does not create a link' do
+        expect(subject.note).to eq('changed this line in version 1 of the diff')
+      end
     end
   end