title: How to stub the return value on a mocked method in SinonJS
body: <p>I want to do something like the following:</p>
  
  <pre><code>sinon.mock(obj)
  .expects('func')
  .atLeast(1)
  .withArgs(args)
  .returns(somePredefinedReturnValue);
  </code></pre>
  
  <p>Where I expect everything up to and including withArgs, but then I need to stub the return value of the method so that when it returns it doesn't break the rest of the execution flow within the method under test.</p>
  
  <p>The reason I'm doing this is because I found out that some of my REST endpoint tests will silently pass when they should really be failing if a stubbed method with a callback that has an assertion inside of it doesn't get called.  I'm trying to verify that these callbacks are actually getting called so that my tests don't give false positives.</p>