Rails /w Ruby 1.9.1p243 - Unit Test assert_equal question

Hi everyone

I am new to Rails. My platform is Ubuntu 9.04 with Ruby 1.9.1p243 and
Rails 2.3.4. I am reading SitePoint's Simply Rails 2 book. On page
240, the author shows how to test the associations between Story and
Vote model.

The code is below

app/models/story.rb:

because arrays are fundamentally ordered collections so for an array
== means same elements and in the same order. Whenever you get
something out of the database and there is no order clause (eg if you
do Vote.all, or the association you have here) the database is free to
return stuff in any order it wants to. Quite often it will be mostly
the same order each time but you shouldn't rely on that (more often
than not it will something to do with the order things are stored in
on disk.

Fred