added tests

spec/controllers/exercises_controller_spec.rb

@@ -7,6 +7,8 @@ describe ExercisesController do
 
   describe 'POST #clone' do
     let(:request) { proc { post :clone, id: exercise.id } }
+
+    context 'when saving succeeds' do
       before(:each) { request.call }
 
       expect_assigns(exercise: Exercise)
@@ -23,6 +25,19 @@ describe ExercisesController do
       expect_redirect
     end
 
+    context 'when saving fails' do
+      before(:each) do
+        expect_any_instance_of(Exercise).to receive(:save).and_return(false)
+        request.call
+      end
+
+      expect_assigns(exercise: Exercise)
+
+      expect_flash_message(:danger)
+      expect_redirect(:exercise)
+    end
+  end
+
   describe 'POST #create' do
     let(:exercise_attributes) { FactoryGirl.build(:dummy).attributes }
 

spec/support/controllers.rb

@@ -21,9 +21,13 @@ def expect_content_type(content_type)
   end
 end
 
-def expect_flash_message(type, message)
+def expect_flash_message(type, message = nil)
   it 'displays a flash message' do
+    if message
       expect(flash[type]).to eq(message.is_a?(String) ? message : I18n.t(message))
+    else
+      expect(flash[type]).to be_present
+    end
   end
 end