added mailer

spec/features/support_spec.rb

@@ -20,7 +20,10 @@ feature 'Support announcement' do
 
     sleep 5 # Do a real sleep to have a real integration test
 
+    expect(ActionMailer::Base.deliveries.count).to eq 0
     expect { click_button 'Unterstützung zusichern' }.to change { Supporter.count }.by(1)
+    expect(ActionMailer::Base.deliveries.count).to eq 1
+
     supporter = Supporter.find_by(email: 'blocher@blocher.ch')
     expect(supporter.coordinates).to eq [8.618589100000001, 47.2926304]
     expect(supporter.comments).to eq 'Test text'

spec/mailers/previews/supporter_mailer_preview.rb

@@ -0,0 +1,6 @@
+# Preview all emails at http://localhost:3000/rails/mailers/supporter_mailer
+class SupporterMailerPreview < ActionMailer::Preview
+  def welcome
+    SupporterMailer.welcome_email(Supporter.first)
+  end
+end

spec/spec_helper.rb

@@ -44,4 +44,8 @@ RSpec.configure do |config|
   config.after(:each) do
     Mongoid.purge!
   end
+
+  config.before(:each) do
+    ActionMailer::Base.deliveries.clear
+  end
 end