fake_active_record_model.rb

module FakeActiveRecord
  class Errors < Hash
    alias_method :count, :size
    def full_messages
      map do |key, message|
        "#{message}"
      end
    end
  end
end

class Invitation < ActiveRecord::Base
  attr_reader :user_email, :invited_email, :message, :errors
  EMAIL_FORMAT = /^[A-Z0-9._%+-]+@[A-Z0-9.-]+\.[A-Z]{2,4}$/i

  def initialize(params)
    @errors = FakeActiveRecord::Errors.new
    %w[user_email invited_email message].each do |ivar|
      instance_variable_set("@#{ivar}", params[ivar.to_sym]) unless params.nil?
    end
  end

  def save
    unless @user_email.match(EMAIL_FORMAT)
      @errors[:user_email] = "Your email is invalid"
    end
    unless @invited_email.match(EMAIL_FORMAT)
      @errors[:invited_email] = "Your friend's email is invalid"
    end

    if @errors.empty?
      NetworkingMailer.deliver_invitation(self)
      self
    else
      false
    end
  end

  def new_record?
    true
  end

end