spec/lib/danica/sum_spec.rb in danica-2.0.1 vs spec/lib/danica/sum_spec.rb in danica-2.0.2

@@ -1,7 +1,11 @@
 require 'spec_helper'
 
 describe Danica::Sum do
+  subject { described_class.new(10, 2) }
+
+  it_behaves_like 'an object with + operation'
+
   it_behaves_like 'a operator that joins many variables with same operation', {
     calculated: 10,
     numeric_variables: [ 1.5, 2.5, 3.5 ],
     to_tex: {
       string_expected: 'X1 + X2 + X3 + X4',