API v3: make polymorphic has_many work

lib/travis/api/v3/extensions/belongs_to.rb

@@ -27,6 +27,11 @@ module Travis::API::V3
           polymorfic_foreign_types << (options[:foreign_type] || "#{field}_type") if options[:polymorphic]
           super
         end
+
+        def name
+          return super unless caller_locations.first.base_label == 'add_constraints'.freeze
+          @constraint_name ||= super.sub("#{parent}::", ''.freeze)
+        end
       end
 
       def self.included(base)

spec/v3/extensions/belongs_to_spec.rb

@@ -13,5 +13,6 @@ describe Travis::API::V3::Extensions::BelongsTo do
 
     example { expect(repo.owner).to be_a(Travis::API::V3::Models::User) }
     example { expect(::Repository.find(repo.id).owner).to be_a(::User)  }
+    example { expect(user.repositories).to include(repo)                }
   end
 end