[erlang-questions] test driven development

[Andrew Arrow]

I've just finished the Joe Armstrong book (coming from a Java and Ruby
background) and I noticed there was nothing in the book about test
driven development.

Is the idea that Erlang forces you to write such bug free code there
are no need for tests?  Or was this simply beyond the scope of the
book?

Do professional Erlang programmers create lots of unit and functional
tests like Java and Ruby programmers do?  If so, is there a way to run
all the tests like there is with junit/testng or Test::Unit in ruby?