Verify that ActiveRecord::Base is defined when checking for support

lib/fabrication/generator/active_record.rb

@@ -1,7 +1,11 @@
 class Fabrication::Generator::ActiveRecord < Fabrication::Generator::Base
 
   def self.supports?(klass)
-    defined?(ActiveRecord) && klass.ancestors.include?(ActiveRecord::Base)
+    # Some gems will declare an ActiveRecord module for their own purposes
+    # so we can't assume because we have the ActiveRecord module that we also
+    # have ActiveRecord::Base. Because defined? can return nil we ensure that nil
+    # becomes false.
+    defined?(ActiveRecord) && defined?(ActiveRecord::Base) && klass.ancestors.include?(ActiveRecord::Base) || false
   end
 
   def build_instance

spec/fabrication/generator/active_record_spec.rb

@@ -1,5 +1,22 @@
 require 'spec_helper'
 
+describe Fabrication::Generator::ActiveRecord do
+  describe ".supports?" do
+    subject { Fabrication::Generator::ActiveRecord }
+
+    # Defines a fakey ActiveRecord module that doesn't also have
+    # ActiveRecord::Base such as those written by instrumentation
+    # platforms e.g. Honeycomb
+    module ActiveRecord; end
+
+    let(:active_record_fake) { ActiveRecord }
+
+    it "returns false for active record objects without ar::base" do
+      expect(subject.supports?(active_record_fake)).to be false
+    end
+  end
+end
+
 describe Fabrication::Generator::ActiveRecord, depends_on: :active_record do
 
   describe ".supports?" do