Not helpfull error message in rails.

1_spec_output.markdown

A spec failure when TDDing a has_many_through:

1) Platform should have many interested_parties through platforms_interested_parties
   Failure/Error: it { should have_many(:interested_parties).through(:platforms_interested_parties) }
   NoMethodError:
     undefined method `class_name' for nil:NilClass

Not helpful. The problem here is that I've not yet wired up PlatformsInterestedParty.

Add this and it works:

class PlatformsInterestedParty < ActiveRecord::Base

  belongs_to :platform
  belongs_to :interested_party

end

platform.rb

class Platform < ActiveRecord::Base

  has_many :platforms_interested_parties
  has_many :interested_parties, through: :platforms_interested_parties
  
end

platform_spec.rb

describe Platform do

  it { should have_many(:platforms_interested_parties) }
  it { should have_many(:interested_parties).through(:platforms_interested_parties) }
  
end