cheat sheets.

http://chneukirchen.org/blog/archive/2007/01/announcing-test-spec-0-3-a-bdd-inter
ace-for-test-unit.html

http://weblog.techno-weenie.net/2006/11/24/test-spec-kicks-simply_bdds-ass

Wrapped Assertions:
  assert_equal:           should.equal, should ==
  assert_not_equal:       should.not.equal, should.not ==
  assert_same:            should.be
  assert_not_same:        should.not.be
  assert_nil:             should.be.nil
  assert_not_nil:         should.not.be.nil
  assert_in_delta:        should.be.close
  assert_match:           should.match, should =~
  assert_no_match:        should.not.match, should.not =~
  assert_instance_of:     should.be.an.instance_of
  assert_kind_of:         should.be.a.kind_of
  assert_respond_to:      should.respond_to
  assert_raise:           should.raise
  assert_nothing_raised:  should.not.raise
  assert_throws:          should.throw
  assert_nothing_thrown:  should.not.throw
  assert_block:           should.satisfy

Additional Assertions:
  should.not.satisfy
  a.should.predicate (works like assert a.predicate?)
  a.should.be operator (where operator is <, <=, >, >=, or ===)
  should.output, to check what is printed