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?

1. test/unit example
2. test/unit support not fully implemented yet require ‘model_stubbing/test_case’

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

model User do
    stub :name => 'bob', :admin => false
    stub :admin, :admin => true # inherits from default fixture
  end
end

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

@post   = posts(:default)
@post.user # equal to @admin above

current_time # stubbed to be 6/1/2007 using mocha or rspec

1. rspec example require ‘model_stubbing/spec’

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.

NOTE: This description has been extracted from the Plugin README and so the formatting may need updating to make browser friendly