Check that the new nextRunAt is different that the previous nextRunAt (…

…#858)

lib/job/compute-next-run-at.js

@@ -15,6 +15,7 @@ module.exports = function() {
   const interval = this.attrs.repeatInterval;
   const timezone = this.attrs.repeatTimezone;
   const {repeatAt} = this.attrs;
+  const previousNextRunAt = this.attrs.nextRunAt || new Date();
   this.attrs.nextRunAt = undefined;
 
   const dateForTimezone = date => {
@@ -37,7 +38,7 @@ module.exports = function() {
     try {
       const cronTime = new CronTime(interval);
       let nextDate = cronTime._getNextDateFrom(lastRun);
-      if (nextDate.valueOf() === lastRun.valueOf()) {
+      if (nextDate.valueOf() === lastRun.valueOf() || nextDate.valueOf() <= previousNextRunAt.valueOf()) {
         // Handle cronTime giving back the same date for the next run time
         nextDate = cronTime._getNextDateFrom(dateForTimezone(new Date(lastRun.valueOf() + 1000)));
       }

test/job.js

@@ -223,6 +223,22 @@ describe('Job', () => {
       expect(moment(job.attrs.nextRunAt).toDate().getDate()).to.be(moment(job.attrs.lastRunAt).add(1, 'days').toDate().getDate());
     });
 
+    it('gives the correct nextDate when the lastRun is 1ms before the expected time', () => {
+      // (Issue #858): lastRunAt being 1ms before the nextRunAt makes cronTime return the same nextRunAt
+      const last = new Date();
+      last.setSeconds(59);
+      last.setMilliseconds(999);
+      const next = new Date(last.valueOf() + 1);
+      const expectedDate = new Date(next.valueOf() + 60000);
+      job.attrs.lastRunAt = last;
+      job.attrs.nextRunAt = next;
+      job.repeatEvery('* * * * *', {
+        timezone: 'GMT'
+      });
+      job.computeNextRunAt();
+      expect(job.attrs.nextRunAt.valueOf()).to.be(expectedDate.valueOf());
+    });
+
     describe('when repeat at time is invalid', () => {
       beforeEach(() => {
         job.attrs.repeatAt = 'foo';