SECURITY: Fix XSS on unsubscribed page.

spec/requests/email_controller_spec.rb

@@ -0,0 +1,13 @@
+require 'rails_helper'
+
+RSpec.describe EmailController do
+  describe '#unsubscribed' do
+    describe 'when email is invalid' do
+      it 'should return the right response' do
+        get '/email/unsubscribed', params: { email: 'somerandomstring' }
+
+        expect(response.status).to eq(404)
+      end
+    end
+  end
+end