class MiniTest::Mock

def method_missing(sym, *args) # :nodoc:
  unless @expected_calls.has_key?(sym) then
    raise NoMethodError, "unmocked method %p, expected one of %p" %
      [sym, @expected_calls.keys.sort_by(&:to_s)]
  end
  expected_calls = @expected_calls[sym].select { |call| call[:args].size == args.size }
  if expected_calls.empty?
    arg_sizes = @expected_calls[sym].map { |call| call[:args].size }.uniq.sort
    raise ArgumentError, "mocked method %p expects %s arguments, got %d" %
      [sym, arg_sizes.join('/'), args.size]
  end
  expected_call = expected_calls.find do |call|
    call[:args].zip(args).all? { |mod, a| mod === a or mod == a }
  end
  unless expected_call
    raise MockExpectationError, "mocked method %p called with unexpected arguments %p" %
      [sym, args]
  end
  expected_args, retval = expected_call[:args], expected_call[:retval]
  
  @actual_calls[sym] << {
    :retval => retval,
    :args => expected_args.zip(args).map { |mod, a| mod === a ? mod : a }
  }
  retval
end