s-andringa

class Person < ActiveRecord::Base

  # If I18n.t is evaluated when the model is loaded, which in production happens only once
  # the translation will always use the locale which was set at that moment.
  #
  # (Instead just use the activerecord.errors.person.attributes.email.invalid key in
  # the translation files)
  #
  # This does NOT work properly:
  validates_format_of :email, :with => REGEXP, :message => I18n.t(:email_invalid) 

s-andringa

class Hash
  # Compares two hashes bases on only their keys.
  # Recursively matches nested hashes too.
  #
  # (Used for comparing translations hashes in test.)
  def =~(other, _raise = false)
    if _raise
      raise "Unmatched key: #{self.keys.inspect} / #{other.keys.inspect}" unless self.keys == other.keys 
    end  
    (self.keys == other.keys) && all?{ |k, v| !v.is_a?(Hash)  || other[k].=~(v, _raise)  }

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# test/test_helper.rb

# Make sure the tests fail if it encounters a missing translation:
module I18n
  def self.just_raise(*args)
    raise args.first
  end
end
I18n.exception_handler = :just_raise

s-andringa

class Object
  def metaclass
    class << self; self; end
  end
end

class Tea
  @@liters = 5
  class << Tea
    def spill_all

s-andringa

Processing UsersController#create (for 195.232.229.139 at 2009-06-18 14:50:29) [POST]
  Parameters: {"user"=>{"password_confirmation"=>"[FILTERED]", "password"=>"[FILTERED]", "login"=>"XXX"}, "profile"=>{"first_name"=>"XXX", "last_name"=>"XXX"}, "action"=>"create", "authenticity_token"=>"XXX", "controller"=>"users"}
Sent mail to XXX

=========

Unable to send e-mail! 501 Syntax: HELO hostname


/usr/local/lib/ruby/1.8/net/smtp.rb:679:in `check_response'

s-andringa

# HTTP Basic Auth
class User < ActiveRecord::Base
  has_remote :site => "http://example.com", :user => "foo", :password => "bar" do |remote|
    #...
  end
end
 
# API key
class User < ActiveRecord::Base
  has_remote :site => "http://example.com?api_key=12x34x5" do |remote|

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class User < ActiveRecord::Base
  def email
    # Make REST call, parse response, extract email address and return it.
    # Probably not the most concise and expressive code.
  end
end

# Is more or less equal to:

class RemoteUser < ActiveResource::Base

s-andringa

class Object
  def metaclass
    class << self; self; end
  end
end

# - Normal cases -

class Foo
  @@bar = 0

s-andringa

class Object
  def metaclass
    class << self; return self; end
  end
end

class Foo

  # 1. def within class definition   
  def self.set_a

s-andringa

class ConstantGardener
  
  def self.create(*booleans)
    Class.new do
      def initialize(bitmask)
        @bitmask = bitmask
      end
      
      booleans.each_with_index do |b, i|
        const_set b.to_s.upcase, 2**i