By deferring the evaluation of these messages, we can avoid the
expensive creation of them when in the majority use case (tests are
passing) they are not needed.
These failure messages were causing performance problems with larger
objects needed to be pretty printed as discussed in #520 and brought up
by @rdy.
[fixes#65925900][fixes#520]
Jasmine spies now have a 'and' property which allows the user to
change the spy's execution strategy-- such as '.and.callReturn(4)'
and a 'calls' property which allows inspection of the calls a spy
has received.
* This is a breaking change *
There is a CallTracker that keeps track of all calls and arguments
and a SpyStrategy which determines what the spy should do when it
is called.
