When navigating to the Unit Tests tab and assuming some tests have run, you'll see a web page similar to the one pictured below.
(((((((( PIC HERE ))))))))
The page is split into two, the top part is the summary field and the table underneath lists the tests. The summary field will vary depending on the results of the tests. To keep things simple we've chosen to hide/show certain unit test results in the summary field. Unit tests can have many different results so if there are no tests for a certain result we hide it (except for New Failures). Regardless of the test outcomes we always show New Failures as the default view.
Note: Unit tests can be viewed as soon as the stage they were generated in has completed. Be sure to refresh the page once the build has completed to get an accurate representation of unit tests in the summary field.