model_stubbing

Creates in-memory versions of models for testing. This attempts to solve a few problems with ActiveRecord Fixtures:

Speed - There's no hit to the database and no cleanup between tests. Flexibility - You can define a global set of stubs, or define custom ones for specific tests/specs

A lot of these ideas were taken from various approaches to fixtures and mocking that I've seen:

fixture scenarios (http://errtheblog.com/post/7708) unit_record (http://www.dcmanges.com/blog/rails-unit-record-test-without-the-database) Rspec and #mock_model

Exemplar (http://www.bofh.org.uk/articles/2007/08/05/doing-the-fixture-thing) I actually saw Exemplar after I wrote the initial version, but they do seem similar.

I honestly don't know if this is a better way or anything, I'm just experimenting with a different approach. Oh, and apparently this is an implementation of the ObjectMother (http://www.martinfowler.com/bliki/ObjectMother.html) pattern?

test/unit example

test/unit support not fully implemented yet

require 'model_stubbing'

class FooTest < Test::Unit::TestCase define_models do time 2007, 6, 1

  model Role do
    stub :owner, :name => 'owner'
    stub :author, :name => 'author'
  end

  model User do
    stub :name => 'bob', :admin => false
    stub :admin, :admin => true # inherits from default fixture
    stub :author, :roles => [all_stubs(:author_role)]
    stub :owner, :roles => [all_stubs(:author_role), all_stubs(:owner_role)]
  end

  model Post do
    # uses admin user fixture above
    stub :title => 'initial', :user => all_stubs(:admin_user), 
      :published_at => current_time + 5.days
  end
end

def test_foo
  @user   = users(:default) # default user stub
  @admin  = users(:admin)
  @custom = users(:default, :age => 25) # custom attributes, 
                                        #but not equal to @user any more
                                        
  @post   = posts(:default)
  @post.user # equal to @admin above
  
  current_time # stubbed to be 6/1/2007 using mocha or rspec
end

end

rspec example

require 'model_stubbing'

describe Foo do ... end

TODO

• Support other mocking frameworks besides rspec and mocha?

• Support Sequel, DataMapper, etc? I use AR, but I'm willing to abstract some of that out in case someone wants to support another ORM.