I'm using my MOO project to teach myself Test Driven Design, and it's taking me interesting places. For example, I wrote a test that said an attribute on a particular object should always return an array, so --

t = Thing.new("test")
p t.names  #-> ["test"]

t.names = nil
p t.names #-> []

The code I have for this is okay, but it doesn't seem terribly ruby to me:

class Thing

   def initialize(names)
      self.names = names
   end

   def names=(n)
      n = [] if n.nil?
      n = [n] unless n.instance_of?(Array)

      @names = n
   end

   attr_reader :names
end

Is there a more elegant, Ruby-ish way of doing this?
(NB: if anyone wants to tell me why this is a dumb test to write, that would be interesting too...)