Improve ergonomics with RelativeTimeFormat #34
Description
RelativeTimeFormat only takes a single unit, but a duration always contains an arbitrary number of units. This means if I have a duration representing the difference between two points, I need to round it to a fixed unit (both largest and smallest). The typical idea is to round it to "days, or, if the duration in total is less than 1 day, whatever its largest unit is". This is currently extremely unwieldy to do:
const now = Temporal.now.instant();
const emailSent = Temporal.Instant.from("2024-04-20T12:00:00Z");
const duration = emailSent.since(now).round({ largestUnit: "days" });
const unit = ["days", "hours", "minutes", "seconds"].find((u) => duration[u]);
const durationRounded = duration.round({ smallestUnit: unit });
const time = new Intl.RelativeTimeFormat("en-US").format(durationRounded[unit], unit);I think we can either make a getter like duration.largestUnit, or make RelativeTimeFormat accept a duration object, where it automatically applies said rounding (less ideal because then I can't control the rounding process).