@burglekitt/gmt
Version:
Temporal-based date and time utilities with timezone support and polyfill integration
61 lines (60 loc) • 2.76 kB
JavaScript
/**
* Return true when `pointOrStart` falls within the interval `[intervalStart, intervalEnd]`
* (3-arg), or when the inner interval `[innerStart, innerEnd]` is fully contained within
* the outer interval `[intervalStart, intervalEnd]` (4-arg).
*
* - Compares numeric Unix epoch values directly.
* - Always-inclusive boundaries: `start <= point <= end`.
* - Returns `false` if `intervalStart > intervalEnd` (invalid outer interval).
* - Returns `false` if `innerStart > innerEnd` in 4-arg mode (invalid inner interval).
* - Returns `false` on invalid input (non-numeric types, non-finite values).
*
* @param intervalStart Unix epoch value (seconds or milliseconds) — outer interval start
* @param intervalEnd Unix epoch value (seconds or milliseconds) — outer interval end
* @param pointOrStart Unix epoch value for the point (3-arg) or inner start (4-arg)
* @param pointEnd optional Unix epoch value for the inner interval end (4-arg mode)
* @returns true if the point or inner interval is contained, or false on invalid input
*
* @example intervalContainsUnix(0, 1700000000, 170000000) // true
* @example intervalContainsUnix(0, 1700000000, 170000000, 1500000000) // true
* @example intervalContainsUnix(1700000000, 0, 170000000) // false
* @example intervalContainsUnix(0, 1700000000, 170000000, 15000000) // false
* @example intervalContainsUnix(NaN, 1700000000, 170000000) // false
* @example intervalContainsUnix("0", "1700000000", "170000000") // true
*/
export function intervalContainsUnix(intervalStart, intervalEnd, pointOrStart, pointEnd) {
if (typeof intervalStart !== "number" && typeof intervalStart !== "string") {
return false;
}
if (typeof intervalEnd !== "number" && typeof intervalEnd !== "string") {
return false;
}
if (typeof pointOrStart !== "number" && typeof pointOrStart !== "string") {
return false;
}
if (pointEnd !== undefined &&
typeof pointEnd !== "number" &&
typeof pointEnd !== "string") {
return false;
}
const n1 = typeof intervalStart === "number" ? intervalStart : Number(intervalStart);
const n2 = typeof intervalEnd === "number" ? intervalEnd : Number(intervalEnd);
const n3 = typeof pointOrStart === "number" ? pointOrStart : Number(pointOrStart);
if (!Number.isFinite(n1) || !Number.isFinite(n2) || !Number.isFinite(n3)) {
return false;
}
if (n1 > n2) {
return false;
}
if (pointEnd === undefined) {
return n1 <= n3 && n3 <= n2;
}
const n4 = typeof pointEnd === "number" ? pointEnd : Number(pointEnd);
if (!Number.isFinite(n4)) {
return false;
}
if (n3 > n4) {
return false;
}
return n1 <= n3 && n4 <= n2;
}