title: Why does adding a grails Service unit test breaks controller unit tests?
body: <p>Using Grails version 2.4.2</p>
  
  <p>I have controller unit tests that were passing successfully. 
  As soon as I added a MyServiceSpec that tests a MyService some controller unit tests started failing.
  If I comment out my MyServiceSpec tests they pass again. 
  I have been able to narrow it down to something related to MimeType bean initialization. </p>
  
  <p>If the MyServiceSpec runs then the MimeType printed using </p>
  
  <pre><code>MimeType.getConfiguredMimeTypes().each { MimeType mt -&gt;
             println mt.name
         }
  </code></pre>
  
  <p>outputs</p>
  
  <pre><code>text/html
  </code></pre>
  
  <p>Without the MyServiceSpec it is </p>
  
  <pre><code>application/atom+xml
  text/css
  text/csv
  application/x-www-form-urlencoded
  text/html
  application/xhtml+xml
  text/javascript
  application/json
  text/json
  multipart/form-data
  application/rss+xml
  text/plain
  application/hal+json
  application/hal+xml
  text/xml
  application/xml
  </code></pre>
  
  <p>Without the json mime type the responses are not rendered correctly and the tests fail. I did not see any detailed documentation on allowing or disallowing unit tests for a Service class. </p>
  
  <p>Is it incorrect to have a Service level unit test? Should it be moved to integration test area? Related question is why does default MimeType configuration get wiped out for the other controller tests when  Service unit test is introduced?</p>