ruby script/plugin install http://www.infused.org/svn/plugins/test_injector/

A common model might look like:

class User < ActiveRecord::Base
  has_and_belongs_to_many :groups
  belongs_to :company
  has_many :purchases, :class_name => "Order", :dependent => :nullify
  has_many :subscriptions, :dependent => :destroy
  has_many :newspapers, :through => subscriptions
end

By calling inject_activerecord_tests in the class definition, several test will be injected into the test suite at runtime.

class UserTest < Test::Unit::TestCase
  fixtures :groups, :companies, :orders, :subscriptions, :newspapers
  inject_tests :activerecord
end

Based on the example User class, the following tests will be run (notice that we didn't have to define any test methods in the test class):

def test_has_and_belongs_to_many_groups
  # asserts that groups is an Array of Groups
end

def test_belongs_to_company
  # asserts that company return an instance of Company
end
	
def test_has_many_purchases
  # asserts that purchases is an Array of Purchases
  # asserts that associated purchases's user_id column is nullified when the user is deleted
end
	
def test_has_many_subscriptions
  # asserts that subscriptions is an array of Subscriptions
  # asserts that all subscriptions are destroyed when a User is deleted
end
	
def test_has_many_newspapers_through_subscriptions
  # asserts that newspapers is an array of Newspapers
end
	
def test_fixture_defined_for_companies
  # tests to see if a fixture called 'companies' is defined in the unit test
end
	
def test_fixture_defined_for_purchases
  # tests to see if a fixture called 'orders' is defined in the unit test
end
	
def test_fixture_defined_for_subscriptions
  # tests to see if a fixture called 'subscriptions' is defined in the unit test
end
	
def test_fixture_defined_for_newspapers
  # tests to see if a fixture called 'newspapers' is defined in the unit test
end
	
# if the users table has a 'lock_version' column, one test will be defined
def test_optimistic_locking
  # forces a StaleObjectError in order to test that optimisic locking is functioning correctly
end
	
# if the users table is using the acts_as_versioned plugin by technoweenie, one test will be defined
def test_acts_as_versioned
  # tests that the versioned table is set up correctly by exercising the versioning system
end

You can specify associations that should not be tested when by using the :ignore_associations option:

	
inject_tests :activerecord, :ignore_associations => [:company, :groups]

As long as you use place the inject_tests declaration at the top of the test class, you can override any of the injected tests by redeclaring a method with the same name. See above for the test method naming.

There is currently no advanced documentation for this plugin.