Processes which record all messages they receive
For asserting a process under test called another process in a particular way, currently only exact message matches supported.
is a helper (function) which will handle messaging the Spy process and receiving the list of messages, then scan the list of messages for the one you want to find.
On failure eunit will print out your stdout, which contains the spy's expected message and actual received message list.
Born of necessity (since there is no RSpec for Erlang), contributions and criticisms welcome.