@burglekitt/gmt
Version:
Temporal-based date and time utilities with timezone support and polyfill integration
92 lines (91 loc) • 2.92 kB
JavaScript
import { Temporal } from "@js-temporal/polyfill";
import { isValidTime } from "../validate/index.js";
const supported = [
"day",
"hour",
"minute",
"second",
"millisecond",
"microsecond",
"nanosecond",
];
/**
* Return the end of the specified time `unit` for a given ISO 8601 time string.
*
* - Returns "" for invalid inputs.
*
* @param value ISO 8601 time string
* @param unit EndOfTimeUnit to specify the unit for the end
* @param optionsArg optional: fractionalSecondDigits (number)
* @returns ISO 8601 string representing the end of the specified unit, or "" on invalid input
*
* @example endOfTime("12:34:56", "hour") // "12:59:59.999999999"
* @example endOfTime("invalid", "hour") // ""
*/
export function endOfTime(value, unit, optionsArg) {
const fractionalSecondDigits = optionsArg?.fractionalSecondDigits;
if (!isValidTime(value) || !supported.includes(unit))
return "";
try {
const source = Temporal.PlainTime.from(value);
let result;
switch (unit) {
case "day":
result = source.with({
hour: 23,
minute: 59,
second: 59,
millisecond: 999,
microsecond: 999,
nanosecond: 999,
});
break;
case "hour":
result = source.with({
minute: 59,
second: 59,
millisecond: 999,
microsecond: 999,
nanosecond: 999,
});
break;
case "minute":
result = source.with({
second: 59,
millisecond: 999,
microsecond: 999,
nanosecond: 999,
});
break;
case "second":
result = source.with({
millisecond: 999,
microsecond: 999,
nanosecond: 999,
});
break;
case "millisecond":
result = source.with({ microsecond: 999, nanosecond: 999 });
break;
case "microsecond":
result = source.with({ nanosecond: 999 });
break;
case "nanosecond":
result = source;
break;
default:
return "";
}
// Handle default precision: 0 for > sec, 3 for ms, 6 for µs, 9 for ns
const precisionMap = {
millisecond: 3,
microsecond: 6,
nanosecond: 9,
};
const fractionalDigits = fractionalSecondDigits ?? (precisionMap[unit] || 0);
return result.toString({ fractionalSecondDigits: fractionalDigits });
}
catch {
return "";
}
}