refactor: ♻️ refactor parameters timeZone & utcOffset

refactor runtime check & typings of exclusive parameters timeZone & utcOffset and Add getTimeZoneAndOffset function to utils.ts

src/job.ts

@@ -10,6 +10,7 @@ import {
 	CronOnCompleteCommand,
 	WithOnComplete
 } from './types/cron.types';
+import { getTimeZoneAndOffset } from './utils';
 
 export class CronJob<OC extends CronOnCompleteCommand | null = null, C = null> {
 	cronTime: CronTime;
@@ -61,17 +62,12 @@ export class CronJob<OC extends CronOnCompleteCommand | null = null, C = null> {
 		this.context = (context ?? this) as CronContext<C>;
 
 		// runtime check for JS users
-		if (timeZone != null && utcOffset != null) {
-			throw new ExclusiveParametersError('timeZone', 'utcOffset');
-		}
+		const { timeZone: tz, utcOffset: uo } = getTimeZoneAndOffset(
+			timeZone,
+			utcOffset
+		);
 
-		if (timeZone != null) {
-			this.cronTime = new CronTime(cronTime, timeZone, null);
-		} else if (utcOffset != null) {
-			this.cronTime = new CronTime(cronTime, null, utcOffset);
-		} else {
-			this.cronTime = new CronTime(cronTime, timeZone, utcOffset);
-		}
+		this.cronTime = new CronTime(cronTime, tz, uo as null | undefined);
 
 		if (unrefTimeout != null) {
 			this.unrefTimeout = unrefTimeout;

src/utils.ts

@@ -1,7 +1,25 @@
+import { ExclusiveParametersError } from './errors';
 import { Ranges } from './types/cron.types';
 
 export const getRecordKeys = <K extends Ranges[keyof Ranges]>(
 	record: Partial<Record<K, boolean>>
 ) => {
 	return Object.keys(record) as unknown as (keyof typeof record)[];
 };
+
+export const getTimeZoneAndOffset = (
+	timeZone?: string | null,
+	utcOffset?: number | null
+) => {
+	if (timeZone != null && utcOffset != null) {
+		throw new ExclusiveParametersError('timeZone', 'utcOffset');
+	}
+
+	if (timeZone != null) {
+		return { timeZone, utcOffset: null };
+	} else if (utcOffset != null) {
+		return { timeZone: null, utcOffset };
+	} else {
+		return { timeZone: null, utcOffset: null };
+	}
+};