Add rspec for concern

spec/models/version_spec.rb

@@ -1,5 +1,51 @@
 require 'spec_helper'
 
+module Foo
+  class Base < ActiveRecord::Base
+    self.abstract_class = true
+  end
+
+  class Document < Base
+    has_paper_trail :class_name => 'Foo::Version'
+  end
+
+  class Version < Base
+    include PaperTrail::VersionConcern
+  end
+end
+Foo::Base.establish_connection(:adapter => 'sqlite3', :database => File.expand_path('../../../test/dummy/db/test-foo.sqlite3', __FILE__))
+
+module Bar
+  class Base < ActiveRecord::Base
+    self.abstract_class = true
+  end
+
+  class Document < Base
+    has_paper_trail :class_name => 'Bar::Version'
+  end
+
+  class Version < Base
+    include PaperTrail::VersionConcern
+  end
+end
+Bar::Base.establish_connection(:adapter => 'sqlite3', :database => File.expand_path('../../../test/dummy/db/test-bar.sqlite3', __FILE__))
+
+describe PaperTrail::VersionConcern do
+  it 'allows included class to have different connections' do
+    Foo::Version.connection.should_not eq Bar::Version.connection
+  end
+
+  it 'allows custom version class to share connection with superclass' do
+    Foo::Version.connection.should eq Foo::Document.connection
+    Bar::Version.connection.should eq Bar::Document.connection
+  end
+
+  it 'can be used with class_name option' do
+    Foo::Document.version_class_name.should eq 'Foo::Version'
+    Bar::Document.version_class_name.should eq 'Bar::Version'
+  end
+end
+
 describe PaperTrail::Version do
   describe "Attributes" do
     it { should have_db_column(:item_type).of_type(:string) }