Do not attempt to expand custom action hrefs if the resource does not…

… have any

Fixes https://bugzilla.redhat.com/show_bug.cgi?id=1539741

app/controllers/api/base_controller/renderer.rb

@@ -280,6 +280,7 @@ def fetch_direct_virtual_attribute(type, resource, attr)
       # will not be overwritten later.
       #
       def add_custom_action_hrefs(value)
+        return if value.nil?
         result = value.dup
         result[:buttons].each do |button|
           button["href"] = normalize_href(:custom_buttons, button["id"])

spec/requests/custom_actions_spec.rb

@@ -68,6 +68,8 @@ def expect_result_to_have_custom_actions_hash
   end
 
   describe "Querying services with no custom actions" do
+    let(:service) { FactoryGirl.create(:service) }
+
     it "returns core actions as authorized" do
       api_basic_authorize(action_identifier(:services, :edit),
                           action_identifier(:services, :read, :resource_actions, :get))
@@ -77,6 +79,16 @@ def expect_result_to_have_custom_actions_hash
       expect_result_to_have_keys(%w(id href actions))
       expect(response.parsed_body["actions"].select { |a| a["method"] == "post" }.pluck("name")).to match_array(%w(edit add_resource remove_resource remove_all_resources add_provider_vms))
     end
+
+    it "allows expanding of custom actions" do
+      api_basic_authorize(collection_action_identifier(:services, :read, :get))
+
+      expected = { 'resources' => [a_hash_including('id' => service.id.to_s)] }
+      get(api_services_url, :params => { :expand => "resources", :attributes => "custom_actions" })
+
+      expect(response).to have_http_status(:ok)
+      expect(response.parsed_body).to include(expected)
+    end
   end
 
   describe "Querying services with custom actions" do