title: Rspec how to stub module instance method?
body: <p>B.rb looks like:</p>
  
  <pre><code>module A
     module B
  
       def enabled? xxx
          xxx == 'a'
       end
  
       def disabled? xxx
         xxx != 'a'
       end
     end
  end
  </code></pre>
  
  <p>Another C.rb like:</p>
  
  <pre><code>module YYY
    class C
    include A::B
  
    def a_method 
       if(enabled? xxx) 
         return 'a'
       return 'b'
    end
  end
  </code></pre>
  
  <p>Now I want to write unit tests to test a_method function, </p>
  
  <pre><code> describe :a_method do
      it 'returns a' do
         ###how to sub enabled? method to make it return true....
      end
   end 
  </code></pre>
  
  <p>enabled? is the instance method in the model, I tried </p>
  
  <pre><code>A::B.stub.any_instance(:enabled).and_return true
  </code></pre>
  
  <p>it doesn't work.</p>
  
  <p>anyone can help me????</p>