I agree that this library doesn't looks good — a proper implementation would use a better precision (e.g. 1/10000 of a currency unit) rather than "cents" (1/100

I agree that this library doesn't looks good — a proper implementation would use a better precision (e.g. 1/10000 of a currency unit) rather than "cents" (1/100), and of course, check ranges and the absence of fractions (Number.isSafeInteger).