Factory Girl - Polymorphic Factory

polymorphic_factory.rb

# Setting up a polymorphic factory for a join table
# Since rosterable is not the default name of the model we are calling, we can't use the convenience method
# that is used for area (f.association)
# All we have to do is fall back to the block way of doing it, calling f.rosterable and passing in the
# object you want to populate it with ( in this case a template). This will fill in both rosterable_id
# and rosterable_type for us

Factory.define(:template_rostered_area, :class => RosteredArea) do |f|
  f.association :area
  f.rosterable { |a| a.association(:template)}
end

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