The json keys of ref switcher should not be translated

app/controllers/projects_controller.rb

@@ -247,13 +247,13 @@ class ProjectsController < Projects::ApplicationController
 
     if find_branches
       branches = BranchesFinder.new(@repository, params).execute.take(100).map(&:name)
-      options[s_('RefSwitcher|Branches')] = branches
+      options['Branches'] = branches
     end
 
     if find_tags && @repository.tag_count.nonzero?
       tags = TagsFinder.new(@repository, params).execute.take(100).map(&:name)
 
-      options[s_('RefSwitcher|Tags')] = tags
+      options['Tags'] = tags
     end
 
     # If reference is commit id - we should add it to branch/tag selectbox

changelogs/unreleased/48100-fix-branch-not-shown.yml

+---
+title: Fix branches are not shown in Merge Request dropdown when preferred language
+  is not English
+merge_request: 20016
+author: Hiroyuki Sato
+type: fixed

spec/controllers/projects_controller_spec.rb

@@ -597,6 +597,22 @@ describe ProjectsController do
       expect(parsed_body["Tags"]).to include("v1.0.0")
       expect(parsed_body["Commits"]).to include("123456")
     end
+
+    context "when preferred language is Japanese" do
+      before do
+        user.update!(preferred_language: 'ja')
+        sign_in(user)
+      end
+
+      it "gets a list of branches, tags and commits" do
+        get :refs, namespace_id: public_project.namespace, id: public_project, ref: "123456"
+
+        parsed_body = JSON.parse(response.body)
+        expect(parsed_body["Branches"]).to include("master")
+        expect(parsed_body["Tags"]).to include("v1.0.0")
+        expect(parsed_body["Commits"]).to include("123456")
+      end
+    end
   end
 
   describe 'POST #preview_markdown' do