func Sum()

in src/checkoutservice/money/money.go [93:121]

• 25 lines of code
• 11 McCabe index (conditional complexity)

func Sum(l, r pb.Money) (pb.Money, error) {
	if !IsValid(l) || !IsValid(r) {
		return pb.Money{}, ErrInvalidValue
	} else if l.GetCurrencyCode() != r.GetCurrencyCode() {
		return pb.Money{}, ErrMismatchingCurrency
	}
	units := l.GetUnits() + r.GetUnits()
	nanos := l.GetNanos() + r.GetNanos()

	if (units == 0 && nanos == 0) || (units > 0 && nanos >= 0) || (units < 0 && nanos <= 0) {
		// same sign <units, nanos>
		units += int64(nanos / nanosMod)
		nanos = nanos % nanosMod
	} else {
		// different sign. nanos guaranteed to not to go over the limit
		if units > 0 {
			units--
			nanos += nanosMod
		} else {
			units++
			nanos -= nanosMod
		}
	}

	return pb.Money{
		Units:        units,
		Nanos:        nanos,
		CurrencyCode: l.GetCurrencyCode()}, nil
}