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
  index = @actual_calls[sym].length
  expected_call = @expected_calls[sym][index]
  unless expected_call then
    raise MockExpectationError, "No more expects available for %p: %p" %
      [sym, args]
  end
  expected_args, retval, val_block =
    expected_call.values_at(:args, :retval, :block)
  if val_block then
    raise MockExpectationError, "mocked method %p failed block w/ %p" %
      [sym, args] unless val_block.call(args)
    # keep "verify" happy
    @actual_calls[sym] << expected_call
    return retval
  end
  if expected_args.size != args.size then
    raise ArgumentError, "mocked method %p expects %d arguments, got %d" %
      [sym, expected_args.size, args.size]
  end
  fully_matched = expected_args.zip(args).all? { |mod, a|
    mod === a or mod == a
  }
  unless fully_matched then
    raise MockExpectationError, "mocked method %p called with unexpected arguments %p" %
      [sym, args]
  end
  @actual_calls[sym] << {
    :retval => retval,
    :args => expected_args.zip(args).map { |mod, a| mod === a ? mod : a }
  }
  retval
end