Add render_ce to render CE partial in EE partial

app/views/shared/issuable/form/_default_templates.html.haml

+%p.form-text.text-muted
+  Add
+  = link_to 'description templates', help_page_path('user/project/description_templates'), tabindex: -1
+  to help your contributors communicate effectively!

app/views/shared/issuable/form/_title.html.haml

@@ -30,10 +30,4 @@
         merge request from being merged before it's ready.
 
   - if no_issuable_templates && can?(current_user, :push_code, issuable.project)
-    - if @project.feature_available?(:issuable_default_templates)
-      %p.form-text.text-muted
-        Add
-        = link_to 'description templates', help_page_path('user/project/description_templates'), tabindex: -1
-        to help your contributors communicate effectively!
-    - elsif show_promotions?
-      = render 'shared/promotions/promote_issue_templates'
+    = render 'shared/issuable/form/default_templates'

ee/app/helpers/ee/application_helper.rb

@@ -10,6 +10,30 @@ module EE
         { primary_node: link_to('primary node', ::Gitlab::Geo.primary_node.url) }).html_safe
     end
 
+    def render_ce(partial)
+      render template: find_ce_partial(partial)
+    end
+
+    def find_ce_partial(partial)
+      ce_lookup_context.find(partial, [], true)
+    end
+
+    def ce_lookup_context
+      @ce_lookup_context ||= begin
+        context = lookup_context.dup
+
+        # This could duplicate the paths we're going to modify
+        context.view_paths = lookup_context.view_paths.paths
+
+        # Discard lookup path ee/ for the new paths
+        context.view_paths.paths.delete_if do |resolver|
+          resolver.to_path.start_with?("#{Rails.root}/ee")
+        end
+
+        context
+      end
+    end
+
     def page_class
       class_names = super
       class_names += system_message_class

ee/app/views/shared/issuable/form/_default_templates.html.haml

+- if @project.feature_available?(:issuable_default_templates)
+  = render_ce 'shared/issuable/form/default_templates'
+- elsif show_promotions?
+  = render 'shared/promotions/promote_issue_templates'

ee/spec/helpers/application_helper_spec.rb

@@ -12,4 +12,39 @@ describe ApplicationHelper do
       end
     end
   end
+
+  context 'when both CE and EE has partials with the same name' do
+    let(:partial) { 'shared/issuable/form/default_templates' }
+    let(:project) { build_stubbed(:project) }
+
+    describe '#render_ce' do
+      before do
+        helper.instance_variable_set(:@project, project)
+
+        allow(project).to receive(:feature_available?)
+      end
+
+      it 'renders the CE partial' do
+        helper.render_ce(partial)
+
+        expect(project).not_to receive(:feature_available?)
+      end
+    end
+
+    describe '#find_ce_partial' do
+      let(:expected_partial_path) do
+        "app/views/#{File.dirname(partial)}/_#{File.basename(partial)}.html.haml"
+      end
+
+      it 'finds the CE partial' do
+        ce_partial = helper.find_ce_partial(partial)
+
+        expect(ce_partial.inspect).to eq(expected_partial_path)
+
+        # And it could still find the EE partial
+        ee_partial = helper.lookup_context.find(partial, [], true)
+        expect(ee_partial.inspect).to eq("ee/#{expected_partial_path}")
+      end
+    end
+  end
 end