gold.rb

require 'bacon'
require 'rubyqc'

Bacon.summary_on_exit
Bacon::Context.include RubyQC::API

class User < Struct.new(:name, :gold)
  def self.rubyqc
    new(String.rubyqc, (0..99).rubyqc)
  end

  def give that, amount
    if gold >= amount
      self.gold -= amount
      that.gold += amount
      true
    else
      false
    end
  end
end

describe User do
  should 'Generate random users' do
    check(User) do |user|
      user     .should.kind_of User
      user.name.should.kind_of String
      user.gold.should.kind_of Fixnum
    end
  end

  should 'Give gold to others' do
    check(User, User, 0..99) do |a, b, gold|
      total = a.gold + b.gold
      agold = a.gold

      a.give(b, gold).should == gold <= agold

      a.gold.should >= 0
      b.gold.should >= 0
      (a.gold + b.gold).should == total
    end
  end
end