Fix bug with wiki async loading and relative url

app/helpers/wiki_helper.rb

@@ -136,7 +136,7 @@ module WikiHelper
   end
 
   def wiki_page_render_api_endpoint(page)
-    api_v4_projects_wikis_path(wiki_page_render_api_endpoint_params(page))
+    expose_path(api_v4_projects_wikis_path(wiki_page_render_api_endpoint_params(page)))
   end
 
   def wiki_markup_hash_by_name_id

ee/app/helpers/ee/wiki_helper.rb

@@ -18,7 +18,7 @@ module EE
     def wiki_page_render_api_endpoint(page)
       return super if page.wiki.is_a?(ProjectWiki)
 
-      api_v4_groups_wikis_path(wiki_page_render_api_endpoint_params(page))
+      expose_path(api_v4_groups_wikis_path(wiki_page_render_api_endpoint_params(page)))
     end
   end
 end

ee/spec/helpers/ee/wiki_helper_spec.rb

@@ -10,4 +10,8 @@ RSpec.describe WikiHelper do
       expect(helper.wiki_attachment_upload_url).to end_with("/api/v4/groups/#{@wiki.group.id}/wikis/attachments")
     end
   end
+
+  it_behaves_like 'wiki endpoint helpers' do
+    let_it_be(:page) { create(:wiki_page, wiki: create(:group_wiki)) }
+  end
 end

spec/helpers/wiki_helper_spec.rb

@@ -145,4 +145,8 @@ RSpec.describe WikiHelper do
       expect(subject).to include('wiki-directory-nest-level' => 0)
     end
   end
+
+  it_behaves_like 'wiki endpoint helpers' do
+    let_it_be(:page) { create(:wiki_page) }
+  end
 end

spec/support/shared_examples/helpers/wiki_helpers_shared_examples.rb

+# frozen_string_literal: true
+
+RSpec.shared_examples 'wiki endpoint helpers' do
+  let(:resource_path) { page.wiki.container.class.to_s.pluralize.downcase }
+  let(:url) { "/api/v4/#{resource_path}/#{page.wiki.container.id}/wikis/#{page.slug}?version=#{page.version.id}"}
+
+  it 'returns the full endpoint url' do
+    expect(helper.wiki_page_render_api_endpoint(page)).to end_with(url)
+  end
+
+  context 'when relative url is set' do
+    let(:relative_url) { "/gitlab#{url}" }
+
+    it 'returns the full endpoint url with the relative path' do
+      stub_config_setting(relative_url_root: '/gitlab')
+
+      expect(helper.wiki_page_render_api_endpoint(page)).to end_with(relative_url)
+    end
+  end
+end