Pre-processing in development mode caches after the first call - which
is usually fine - however, when using an erb template with potentially
dynamic output, the cache doesn't clear.
"time.js.erb", which outputs an alert with like so:-
alert('<%= Time.now %>');
I only get the time for the first request and all other requests are
the cached result. Surely the cache should be invalidated when the
dynamic erb output changes?