thoughtbot

$ time rake test:parallel
(in /Users/jasonmorrison/dev/myapp/trunk)
2 processes for 49 tests, ~ 24 tests per process
Loaded suite -e
Started
.................................. (abbreviated)

29.32s user 3.31s system 143% cpu 22.669 total

thoughtbot

$ time rake test:units test:functionals
Started
.......... (abbreviated... FOR BLOG READING SPEED!!)

415 tests, 898 assertions, 0 failures, 0 errors

29.14s user 3.74s system 87% cpu 37.614 total

thoughtbot

$ script/plugin install git://github.com/jasonm/parallel_specs.git

thoughtbot

$ rake db:structure:dump
$ echo "create database myapp_test2;" | mysql -uroot
$ mysql -uroot -Dmyapp_test2 < db/development_structure.sql
$ vim config/database.yml # add some ERB to config/database.yml

  test:
    adapter: mysql
    encoding: utf8
    database: myapp_test<%= ENV['TEST_ENV_NUMBER'] %>
    username: root

thoughtbot

$ time rake test:parallel
(in /Users/jasonmorrison/dev/myapp/trunk)
2 processes for 49 tests, ~ 24 tests per process
Loaded suite -e
Started
.................................. (abbreviated)

29.32s user 3.31s system 143% cpu 22.669 total

thoughtbot

posts = Post.find do
    user.email =~ "%thoughtbot%"
    tags.name === %w( ruby rails )
    created_on <=> [ 2.weeks.ago, 1.week.ago ]
end

thoughtbot

query = User.find do
    company.name = cname?
    order_by created_on
end

thoughtbot

users = query.find(:cname => "thoughtbot")
</code></pre>

Now, what's tricky is that you could pass any syntax-changing value to that and you'd get the right SQL in the executed query.

<filter:code lang="ruby">
query.find :cname => "thoughtbot"              # =>   company.name = "thoughtbot"
query.find :cname => nil                       # =>   company.name IS NULL
query.find :cname => ["Google", "37 Signals"]  # =>   company.name IN ("Google", "37 Signals")

thoughtbot

class Person < ActiveRecord::Base

  has_one :address, :as => :addressable

end

class Company < ActiveRecord::Base

  has_one :address, :as => :addressable

thoughtbot

class  Address < ActiveRecord::Base

  belongs_to :person
  belongs_to :company

end