explicitly specify group name

app/controllers/discourse_donations/charges_controller.rb

@@ -18,9 +18,9 @@ module DiscourseDonations
 
       if reward_user?(payment)
         reward = DiscourseDonations::Rewards.new(current_user)
-        group_name = SiteSetting.discourse_donations_reward_group
+        group_name = SiteSetting.discourse_donations_reward_group_name
         if reward.add_to_group(group_name)
-          response['rewards']['groups'] = [SiteSetting.discourse_donations_reward_group]
+          response['rewards']['groups'] = [group_name]
         end
       end
 

config/settings.yml

@@ -18,6 +18,6 @@ plugins:
   discourse_donations_reward_badge:
     client: false
     default: 'Donation'
-  discourse_donations_reward_group:
+  discourse_donations_reward_group_name:
     client: false
     default: 'Donation'

spec/controllers/discourse_donations/charges_controller_spec.rb

@@ -29,8 +29,8 @@ module DiscourseDonations
 
     describe 'rewards' do
       before do
-        SiteSetting.stubs(:discourse_donations_reward_group).returns('Skimby')
-        Fabricate(:group, name: SiteSetting.discourse_donations_reward_group)
+        SiteSetting.stubs(:discourse_donations_reward_group_name).returns('Skimby')
+        Fabricate(:group, name: SiteSetting.discourse_donations_reward_group_name)
         log_in :coding_horror
       end
 
@@ -45,7 +45,7 @@ module DiscourseDonations
 
       it 'awards a group' do
         post :create
-        expect(response_rewards['groups']).to eq([SiteSetting.discourse_donations_reward_group])
+        expect(response_rewards['groups']).to eq([SiteSetting.discourse_donations_reward_group_name])
       end
     end
   end