Add tests

test/models/pop_test.rb

@@ -1,7 +1,8 @@
 require "test_helper"
 
 class PopTest < ActiveSupport::TestCase
-  # test "the truth" do
-  #   assert true
-  # end
+  test "default to the fallback reason if no reason is given" do
+    assert_equal "Not now", Pop.new(reason: "Not now").reason
+    assert_equal Account::PopReasons::FALLBACK_LABEL, Pop.new.reason
+  end
 end