an unexplained invocation of Math.random() in the exception handling block of this MongoDB java driver class causes roflscale lols in the github commit notes. http://stackoverflow.com/a/16833798 has more explanation.
‘What is a Hermetic Server? The short definition would be a “server in a box”. If you can start up the entire server on a single machine that has no network connection AND the server works as expected, you have a hermetic server! This is a special case of the more general “hermetic” concept which applies to an isolated system not necessarily on a single machine. Why is it useful to have a hermetic server? Because if your entire [system under test] is composed of hermetic servers, it could all be started on a single machine for testing; no network connection necessary! The single machine could be a physical or virtual machine.’ These also qualify as “fakes”, using the terminology Martin Fowler suggests at http://martinfowler.com/bliki/TestDouble.html , I think
hooray, sanity from the Google Testing blog. this has been a major cause of pain in the past, dealing with tricky rewrites of mock-heavy unit test code