title: Testing a ReactiveVar in Meteor
body: <p>I am trying to test a event in a Template. Within the click event, there is a Reactive Var that gets set.</p>
  
  <p>The test is blocked by the Reactive Var.</p>
  
  <p>Any ideas on how I stub or mock a reactive var in a template? I tried adding it to the template (template.reactiveVar = "whatever"), but no go, as I don't think it's writeable.</p>
  
  <p>The ?? indicate where I am wondering what to put.</p>
  
  <p>it('sets a reactive var when a button is clicked', function(){</p>
  
  <pre><code>Template.button.fireEvent('click ', {
      context: { some: 'values'},
      event: {'target': {'text': 'randomText' } },
      templateInstance:new Template('upload', function(e) {
          this.reactiveVar = new ReactiveVar("not clicked)
      })
  });
  
  chai.assert.equal(Template.reactiveVar, "clicked")});
  
  // The actual template is below.. 
  
  Template.button.events{(
   'click button': function(evt, template){
     var text = evt.target.text
     template.reactiveVar.set(text)
    }
  });
  </code></pre>
  
  <p>The result is...
  TypeError: Cannot read property 'set' of undefined</p>
  
  <p>Any ideas?</p>