Rails & RSpec - Testing Concerns class methods

Question

I have the following (simplified) Rails Concern:

module HasTerms   extend ActiveSupport::Concern    module ClassMethods     def optional_agreement       # Attributes       #----------------------------------------------------------------------------       attr_accessible :agrees_to_terms     end      def required_agreement       # Attributes       #----------------------------------------------------------------------------       attr_accessible :agrees_to_terms        # Validations       #----------------------------------------------------------------------------       validates :agrees_to_terms, :acceptance => true, :allow_nil => :false, :on => :create     end   end end 

I can't figure out a good way to test this module in RSpec however - if I just create a dummy class, I get active record errors when I try to check that the validations are working. Has anyone else faced this problem?

Answer 1

Check out RSpec shared examples.

This way you can write the following:

# spec/support/has_terms_tests.rb shared_examples "has terms" do    # Your tests here end   # spec/wherever/has_terms_spec.rb module TestTemps   class HasTermsDouble     include ActiveModel::Validations     include HasTerms   end end  describe HasTerms do    context "when included in a class" do     subject(:with_terms) { TestTemps::HasTermsDouble.new }      it_behaves_like "has terms"   end  end   # spec/model/contract_spec.rb describe Contract do    it_behaves_like "has terms"  end 

Answer 2

You could just test the module implicitly by leaving your tests in the classes that include this module. Alternatively, you can include other requisite modules in your dummy class. For instance, the validates methods in AR models are provided by ActiveModel::Validations. So, for your tests:

class DummyClass   include ActiveModel::Validations   include HasTerms end 

There may be other modules you need to bring in based on dependencies you implicitly rely on in your HasTerms module.