Factory Girl and has_one

If that's the case I would add the association into the other factory:

Factory.define :video do |v|
  v.filename                        {Sham.filename}
  v.video_url                       {Sham.url}
  v.audition                        {|v| v.association(:audition)}
end

Then you can do

v = Factory(:video) # This will now have an audition
a = v.audition # This should not be nil

and

a = Factory(:audition) # An audition without a video, if that's possible?

You can also override any association as needed when you create the factory in your tests, i.e:

v = Factory(:video, :audition => Factory(:audition))
v = Factory(:video, :audition => nil)

Hope what I've said makes sense and is true lol. Let us know how you get on.