add rewards to response

app/controllers/discourse_donations/charges_controller.rb

@@ -14,12 +14,14 @@ module DiscourseDonations
         response = {}
       end
 
-      response['rewards'] = []
+      response['rewards'] = {}
 
       if reward_user?(payment)
         reward = DiscourseDonations::Rewards.new(current_user)
         group_name = SiteSetting.discourse_donations_reward_group
-        reward.add_to_group(group_name) if group_name.present?
+        if reward.add_to_group(group_name)
+          response['rewards']['groups'] = [SiteSetting.discourse_donations_reward_group]
+        end
       end
 
       render :json => response

app/services/discourse_donations/rewards.rb

@@ -8,7 +8,9 @@ module DiscourseDonations
 
     def add_to_group(name)
       group = ::Group.find_by_name(name)
-      group.add(@user) if group.present?
+      return false if group.nil?
+      group.add(@user)
+      group.present?
     end
   end
 end

spec/controllers/discourse_donations/charges_controller_spec.rb

@@ -27,10 +27,26 @@ module DiscourseDonations
       expect(response).to have_http_status(200)
     end
 
-    it 'has no rewards' do
-      current_user = log_in(:coding_horror)
-      post :create
-      expect(JSON.parse(response.body)['rewards']).to eq([])
+    describe 'rewards' do
+      before do
+        SiteSetting.stubs(:discourse_donations_reward_group).returns('Skimby')
+        Fabricate(:group, name: SiteSetting.discourse_donations_reward_group)
+        log_in :coding_horror
+      end
+
+      let(:response_rewards) { JSON.parse(response.body)['rewards'] }
+      let(:stripe) { ::Stripe::Charge }
+
+      it 'has no rewards' do
+        stripe.expects(:create).returns({ bummer: true })
+        post :create
+        expect(response_rewards).to eq({})
+      end
+
+      it 'awards a group' do
+        post :create
+        expect(response_rewards['groups']).to eq([SiteSetting.discourse_donations_reward_group])
+      end
     end
   end
 end

spec/services/discourse_donations/rewards_spec.rb

@@ -9,7 +9,12 @@ module DiscourseDonations
     it 'adds the user to a group' do
       Group.expects(:find_by_name).with(grp.name).returns(grp)
       grp.expects(:add).with(user)
-      subject.add_to_group(grp.name)
+      expect(subject.add_to_group(grp.name)).to eq true
+    end
+
+    it 'does not add the user to a group' do
+      Group.expects(:find_by_name).with(grp.name).returns(nil)
+      expect(subject.add_to_group(grp.name)).to eq false
     end
 
     it 'grants the user a badge'