Fix failling tests

.rubocop_manual_todo.yml

@@ -1566,6 +1566,7 @@ Gitlab/NamespacedClass:
     - 'app/models/concerns/uniquify.rb'
     - 'app/models/container_expiration_policy.rb'
     - 'app/models/container_repository.rb'
+    - 'app/models/context_commits_diff.rb'
     - 'app/models/custom_emoji.rb'
     - 'app/models/data_list.rb'
     - 'app/models/deploy_key.rb'
@@ -1980,6 +1981,7 @@ Gitlab/NamespacedClass:
     - 'app/serializers/container_repository_entity.rb'
     - 'app/serializers/container_tag_entity.rb'
     - 'app/serializers/container_tags_serializer.rb'
+    - 'app/serializers/context_commits_diff_entity.rb'
     - 'app/serializers/current_board_entity.rb'
     - 'app/serializers/current_board_serializer.rb'
     - 'app/serializers/current_user_entity.rb'

app/assets/javascripts/diffs/components/compare_dropdown_layout.vue

@@ -40,7 +40,9 @@ export default {
           <strong>
             {{ version.versionName }}
             <template v-if="version.isHead">{{ s__('DiffsCompareBaseBranch|(HEAD)') }}</template>
-            <template v-else-if="version.isBase">{{ s__('DiffsCompareBaseBranch|(base)') }}</template>
+            <template v-else-if="version.isBase">{{
+              s__('DiffsCompareBaseBranch|(base)')
+            }}</template>
           </strong>
         </div>
         <div>

app/assets/javascripts/diffs/store/getters_versions_dropdowns.js

@@ -7,7 +7,6 @@ export const selectedTargetIndex = (state) =>
 
 export const selectedSourceIndex = (state) => state.mergeRequestDiff.version_index;
 
-
 export const selectedContextCommitsDiffs = (state) =>
   state.contextCommitsDiff && state.contextCommitsDiff.showing_context_commits_diff;
 
@@ -73,7 +72,8 @@ export const diffCompareDropdownSourceVersions = (state, getters) => {
       versionName: isLatestVersion
         ? __('latest version')
         : sprintf(__(`version %{versionIndex}`), { versionIndex: v.version_index }),
-      selected: v.version_index === getters.selectedSourceIndex && !getters.selectedContextCommitsDiffs,
+      selected:
+        v.version_index === getters.selectedSourceIndex && !getters.selectedContextCommitsDiffs,
     };
   });
 

app/models/context_commits_diff.rb

@@ -43,8 +43,8 @@ class ContextCommitsDiff
     @compare ||=
       Gitlab::Git::Compare.new(
         merge_request.project.repository.raw_repository,
-        commits.last.diff_refs.base_sha,
-        commits.first.diff_refs.head_sha
+        commits.last&.diff_refs&.base_sha,
+        commits.first&.diff_refs&.head_sha
       )
   end
 

app/models/merge_request.rb

@@ -1904,6 +1904,7 @@ class MergeRequest < ApplicationRecord
       ContextCommitsDiff.new(self)
     end
   end
+
   private
 
   def missing_report_error(report_type)

locale/gitlab.pot

@@ -38396,6 +38396,9 @@ msgid_plural "points"
 msgstr[0] ""
 msgstr[1] ""
 
+msgid "previously merged commits"
+msgstr ""
+
 msgid "private"
 msgstr ""
 

spec/controllers/projects/merge_requests/diffs_controller_spec.rb

@@ -180,7 +180,8 @@ RSpec.describe Projects::MergeRequests::DiffsController do
           start_version: nil,
           start_sha: nil,
           commit: nil,
-          latest_diff: true
+          latest_diff: true,
+          only_context_commits: false
         }
 
         expect_next_instance_of(DiffsMetadataSerializer) do |instance|
@@ -261,7 +262,8 @@ RSpec.describe Projects::MergeRequests::DiffsController do
           start_version: nil,
           start_sha: nil,
           commit: nil,
-          latest_diff: true
+          latest_diff: true,
+          only_context_commits: false
         }
 
         expect_next_instance_of(DiffsMetadataSerializer) do |instance|
@@ -290,7 +292,8 @@ RSpec.describe Projects::MergeRequests::DiffsController do
           start_version: nil,
           start_sha: nil,
           commit: merge_request.diff_head_commit,
-          latest_diff: nil
+          latest_diff: nil,
+          only_context_commits: false
         }
 
         expect_next_instance_of(DiffsMetadataSerializer) do |instance|

spec/serializers/diffs_metadata_entity_spec.rb

@@ -28,7 +28,7 @@ RSpec.describe DiffsMetadataEntity do
         :start_version, :latest_diff, :latest_version_path,
         :added_lines, :removed_lines, :render_overflow_warning,
         :email_patch_path, :plain_diff_path,
-        :merge_request_diffs, :context_commits,
+        :merge_request_diffs, :context_commits, :context_commits_diff,
         :definition_path_prefix, :source_branch_exists,
         :can_merge, :conflict_resolution_path, :has_conflicts,
         :project_name, :project_path, :user_full_name, :username,