implemented partial batch update for exercises

spec/controllers/exercises_controller_spec.rb

@@ -5,6 +5,20 @@ describe ExercisesController do
   let(:user) { FactoryGirl.create(:admin) }
   before(:each) { allow(controller).to receive(:current_user).and_return(user) }
 
+  describe 'PUT #batch_update' do
+    let(:attributes) { {public: true} }
+    let(:request) { proc { put :batch_update, exercises: {0 => attributes.merge(id: exercise.id)} } }
+    before(:each) { request.call }
+
+    it 'updates the exercises' do
+      expect_any_instance_of(Exercise).to receive(:update).with(attributes)
+      request.call
+    end
+
+    expect_json
+    expect_status(200)
+  end
+
   describe 'POST #clone' do
     let(:request) { proc { post :clone, id: exercise.id } }
 

spec/policies/exercise_policy_spec.rb

@@ -5,6 +5,15 @@ describe ExercisePolicy do
 
   let(:exercise) { FactoryGirl.build(:dummy, team: FactoryGirl.create(:team)) }
 
+  permissions :batch_update? do
+    it 'grants access to admins only' do
+      expect(subject).to permit(FactoryGirl.build(:admin), exercise)
+      [:external_user, :teacher].each do |factory_name|
+        expect(subject).not_to permit(FactoryGirl.build(factory_name), exercise)
+      end
+    end
+  end
+
   [:create?, :index?, :new?].each do |action|
     permissions(action) do
       it 'grants access to admins' do