Has Many through factory with fabricator

gistfile1.rb

class Country < ActiveRecord::Base
  has_many :registrations
  has_many :members
  has_many :distribution_groups, :through => :members
end

class DistributionGroup < ActiveRecord::Base
  has_many :members
  has_many :countries, :through => :members
end

class Member < ActiveRecord::Base
  belongs_to :country
  belongs_to :distribution_group
end

Fabricator(:country) do
  name { Faker::Address.country }
end 

Fabricator(:member) do
end

Fabricator(:distribution_group) do
  name { Faker::Lorem.words(3).join(" ") }
  after_build do |distribution_group|
    2.times { Fabricate(:member, :distribution_group => distribution_group, :country => Fabricate(:country)) }
  end
end