```ruby
# spec/spec_helper_lite.rb
require 'rr'
require 'date'
require 'ostruct'
require 'active_support'
require 'active_support/deprecation'
require 'activerecord-nulldb-adapter'
require 'minitest/autorun'

def stub_module(full_name)
  full_name.to_s.split(/::/).inject(Object) do |context, name|
    begin
      context.const_get(name)
    rescue NameError
      context.const_set(name, Module.new)
    end
  end
end

def stub_class(full_name)
  full_name.to_s.split(/::/).inject(Object) do |context, name|
    begin
      context.const_get(name)
    rescue NameError
      context.const_set(name, Class.new)
    end
  end
end

module SpecHelpers
  def setup_nulldb
    schema_path = File.expand_path('../db/schema.rb',
                                   File.dirname(__FILE__))
    ActiveRecord::Base.establish_connection :adapter => :nulldb,
    :schema  => schema_path
    #NullDB.nullify(schema: schema_path)
  end

  def teardown_nulldb
    NullDB.restore
  end
end
```

Add ActiveRecord to store blog posts, but only integraion tests now works. Problem with NullDB and Rails 4
user
```ruby
# spec/spec_helper_lite.rb
require 'rr'
require 'date'
require 'ostruct'
require 'active_support'
require 'active_support/deprecation'
require 'activerecord-nulldb-adapter'
require 'minitest/autorun'

def stub_module(full_name)
  full_name.to_s.split(/::/).inject(Object) do |context, name|
    begin
      context.const_get(name)
    rescue NameError
      context.const_set(name, Module.new)
    end
  end
end

def stub_class(full_name)
  full_name.to_s.split(/::/).inject(Object) do |context, name|
    begin
      context.const_get(name)
    rescue NameError
      context.const_set(name, Class.new)
    end
  end
end

module SpecHelpers
  def setup_nulldb
    schema_path = File.expand_path('../db/schema.rb',
                                   File.dirname(__FILE__))
    NullDB.nullify(schema: schema_path)
  end

  def teardown_nulldb
    NullDB.restore
  end
end
```
assistant