title: Equality operator in Jade
body: <p>I am trying to write a <code>mixin</code> in <code>Jade</code>. I would like to pass a parameter through mixin to build same type of block with different value at different states. In the mixin I want to write a conditional that checks if passed parameter is equal to some value. But unfortunately it is not working and I can't find proper documentation anywhere. My code section is following:</p>
  
  <pre><code>mixin test(id)
      if territoryList
          each val in territoryList
              - if (val.parentArea==id){
                  button.btn.btn-primary.btn-block=val.name
              - }
  </code></pre>
  
  <p>And I am calling it like <code>test('1')</code></p>
  
  <p>What is the problem?</p>