Eager load associations for v3/roles list

Co-authored-by: Seth Boyles <sboyles@pivotal.io>
Co-authored-by: Aakash Shah <ashah@pivotal.io>
Co-authored-by: Jaskanwal Pawar <jpawar@pivotal.io>

Author: 3 people

app/controllers/v3/roles_controller.rb

@@ -29,7 +29,7 @@ def index
     unprocessable!(message.errors.full_messages) unless message.valid?
 
     RoleGuidPopulate.populate
-    roles = RoleListFetcher.fetch(message, readable_roles)
+    roles = RoleListFetcher.fetch(message, readable_roles, eager_loaded_associations: Presenters::V3::RolePresenter.associated_resources)
 
     decorators = []
     decorators << IncludeRoleUserDecorator if IncludeRoleUserDecorator.match?(message.include)

app/fetchers/role_list_fetcher.rb

@@ -4,8 +4,8 @@
 module VCAP::CloudController
   class RoleListFetcher
     class << self
-      def fetch(message, readable_users_dataset)
-        filter(message, readable_users_dataset)
+      def fetch(message, readable_users_dataset, eager_loaded_associations: [])
+        filter(message, readable_users_dataset).eager(eager_loaded_associations)
       end
 
       private

app/models/runtime/role.rb

@@ -81,16 +81,20 @@ class Role < Sequel::Model(
     ).from_self
   )
 
+    many_to_one :user, key: :user_id
+    many_to_one :organization, key: :organization_id
+    many_to_one :space, key: :space_id
+
     def user_guid
-      User.first(id: user_id).guid
+      user.guid
     end
 
     def organization_guid
-      Organization.first(id: organization_id)&.guid
+      organization&.guid
     end
 
     def space_guid
-      Space.first(id: space_id)&.guid
+      space&.guid
     end
 
     def for_space?

app/presenters/v3/role_presenter.rb

@@ -2,6 +2,12 @@
 
 module VCAP::CloudController::Presenters::V3
   class RolePresenter < BasePresenter
+    class << self
+      def associated_resources
+        [:user, :space, :organization]
+      end
+    end
+
     def to_hash
       hash = {
         guid: role.guid,

spec/request/roles_spec.rb

@@ -948,6 +948,19 @@ def make_space_role_for_current_user(type)
       end
     end
 
+    describe 'eager loading' do
+      it 'eager loads associated resources that the presenter specifies' do
+        expect(VCAP::CloudController::RoleListFetcher).to receive(:fetch).with(
+          anything,
+          anything,
+          hash_including(eager_loaded_associations: [:user, :space, :organization])
+        ).and_call_original
+
+        get '/v3/roles', nil, admin_header
+        expect(last_response).to have_status_code(200)
+      end
+    end
+
     context 'listing all roles' do
       let(:expected_codes_and_responses) do
         h = Hash.new(code: 200, response_objects: [space_auditor_response_object, org_auditor_response_object])

spec/unit/fetchers/role_list_fetcher_spec.rb

@@ -20,6 +20,18 @@ module VCAP::CloudController
 
       let(:message) { RolesListMessage.from_params(filters) }
 
+      context 'eager loading associated resources' do
+        let(:filters) { {} }
+
+        it 'eager loads the specified resources for the routes' do
+          results = RoleListFetcher.fetch(message, Role.dataset, eager_loaded_associations: [:user, :space]).all
+
+          expect(results.first.associations.key?(:user)).to be true
+          expect(results.first.associations.key?(:space)).to be true
+          expect(results.first.associations.key?(:organization)).to be false
+        end
+      end
+
       context 'when no filters are specified' do
         let(:filters) { {} }