Add a few more tests and make sure empty value sets to nil

app/models/application_setting.rb

@@ -269,6 +269,14 @@ class ApplicationSetting < ActiveRecord::Base
     self.repository_storages = [value]
   end
 
+  def default_artifacts_expire_in=(value)
+    if value.present?
+      super(value.strip)
+    else
+      super(nil)
+    end
+  end
+
   # Choose one of the available repository storage options. Currently all have
   # equal weighting.
   def pick_repository_storage

spec/models/application_setting_spec.rb

@@ -29,6 +29,28 @@ describe ApplicationSetting, models: true do
       it { is_expected.not_to allow_value(['test']).for(:disabled_oauth_sign_in_sources) }
     end
 
+    describe 'default_artifacts_expire_in' do
+      it 'sets an error if it is invalid' do
+        setting.update(default_artifacts_expire_in: 'a')
+
+        expect(setting).to be_invalid
+      end
+
+      it 'sets the value if it is valid' do
+        setting.update(default_artifacts_expire_in: '30 days')
+
+        expect(setting).to be_valid
+        expect(setting.default_artifacts_expire_in).to eq('30 days')
+      end
+
+      it 'does not set it if it is blank' do
+        setting.update(default_artifacts_expire_in: ' ')
+
+        expect(setting).to be_valid
+        expect(setting.default_artifacts_expire_in).to be_nil
+      end
+    end
+
     it { is_expected.to validate_presence_of(:max_attachment_size) }
 
     it do

spec/requests/api/settings_spec.rb

@@ -30,8 +30,14 @@ describe API::Settings, 'Settings', api: true  do
 
       it "updates application settings" do
         put api("/application/settings", admin),
-          default_projects_limit: 3, signin_enabled: false, repository_storage: 'custom', koding_enabled: true, koding_url: 'http://koding.example.com',
-          plantuml_enabled: true, plantuml_url: 'http://plantuml.example.com'
+          default_projects_limit: 3,
+          signin_enabled: false,
+          repository_storage: 'custom',
+          koding_enabled: true,
+          koding_url: 'http://koding.example.com',
+          plantuml_enabled: true,
+          plantuml_url: 'http://plantuml.example.com',
+          default_artifacts_expire_in: '2 days'
         expect(response).to have_http_status(200)
         expect(json_response['default_projects_limit']).to eq(3)
         expect(json_response['signin_enabled']).to be_falsey
@@ -41,6 +47,7 @@ describe API::Settings, 'Settings', api: true  do
         expect(json_response['koding_url']).to eq('http://koding.example.com')
         expect(json_response['plantuml_enabled']).to be_truthy
         expect(json_response['plantuml_url']).to eq('http://plantuml.example.com')
+        expect(json_response['default_artifacts_expire_in']).to eq('2 days')
       end
     end