fix: replace loop timeout by max match date (#686)

Author: sheerlox

lib/time.js

@@ -259,19 +259,23 @@ function CronTime(luxon) {
 				throw new Error('ERROR: You specified an invalid date.');
 			}
 
-			// it shouldn't take more than 5 seconds to find the next execution time
-			// being very generous with this. Throw error if it takes too long to find the next time to protect from
-			// infinite loop.
-			const timeout = Date.now() + 5000;
+			/**
+			 * maximum match interval is 8 years:
+			 * crontab has '* * 29 2 *' and we are on 1 March 2096:
+			 * next matching time will be 29 February 2104
+			 * source: https://github.com/cronie-crond/cronie/blob/0d669551680f733a4bdd6bab082a0b3d6d7f089c/src/cronnext.c#L401-L403
+			 */
+			const maxMatch = luxon.DateTime.now().plus({ years: 8 });
+
 			// determine next date
 			while (true) {
 				const diff = date - start;
 
-				// hard stop if the current date is after the expected execution
-				if (Date.now() > timeout) {
+				// hard stop if the current date is after the maximum match interval
+				if (date > maxMatch) {
 					throw new Error(
-						`Something went wrong. It took over five seconds to find the next execution time for the cron job.
-							Please refer to the canonical issue (https://github.com/kelektiv/node-cron/issues/467) and provide the following string if you would like to help debug:
+						`Something went wrong. No execution date was found in the next 8 years.
+							Please provide the following string if you would like to help debug:
 							Time Zone: ${zone || '""'} - Cron String: ${this} - UTC offset: ${date.offset}
 							- current Date: ${luxon.DateTime.local().toString()}`
 					);

tests/cron.test.js

@@ -379,7 +379,7 @@ describe('cron', () => {
 			const clock = sinon.useFakeTimers();
 			const callback = jest.fn();
 
-			var job = cron.job({
+			const job = cron.job({
 				cronTime: '* * * * * *',
 				onTick: callback,
 				runOnInit: true
@@ -768,6 +768,35 @@ describe('cron', () => {
 		expect(callback).toHaveBeenCalledTimes(1);
 	});
 
+	/**
+	 * maximum match interval is 8 years:
+	 * crontab has '* * 29 2 *' and we are on 1 March 2096:
+	 * next matching time will be 29 February 2104
+	 * source: https://github.com/cronie-crond/cronie/blob/0d669551680f733a4bdd6bab082a0b3d6d7f089c/src/cronnext.c#L401-L403
+	 */
+	it('should work correctly for max match interval', () => {
+		const callback = jest.fn();
+		const d = new Date(2096, 2, 1);
+		const clock = sinon.useFakeTimers(d.getTime());
+
+		const job = new cron.CronJob({
+			cronTime: ' * * 29 1 *',
+			onTick: callback,
+			start: true
+		});
+
+		// 7 years, 11 months and 27 days
+		const almostEightYears = 2919 * 24 * 60 * 60 * 1000;
+		clock.tick(almostEightYears);
+		expect(callback).toHaveBeenCalledTimes(0);
+
+		// tick by 1 day
+		clock.tick(24 * 60 * 60 * 1000);
+		clock.restore();
+		job.stop();
+		expect(callback).toHaveBeenCalledTimes(1);
+	});
+
 	describe('with utcOffset', () => {
 		it('should run a job using cron syntax with number format utcOffset', () => {
 			const clock = sinon.useFakeTimers();