Stuck in while loop indefinitely

[JohnyDays]

I found a minimal repro case, it always gets stuck in the 27th cycle (script never ends)

var expression = "0 12 * * *"
var cron = require("cron-parser")
var currentDate = new Date().toISOString()

var iterator = cron.parseExpression(expression, {currentDate:currentDate})

for (var i=0; i<40;i++) {
  console.log(iterator.next().getTime())
}

I have also tried to recreate the parser on every iteration of the loop, but the results were the same.
Any idea what it might be?
Thanks

[santigimeno]

It looks again a DST transition issue. Will look into it when time permits

[santigimeno]

Thanks for the report

[JohnyDays]

Can i somehow disable timezone handling? I don't need it for this particular case
EDIT: Might also be relevant, my timezone is Lisbon (GMT+1 currently because of DST)

[santigimeno]

I would use the latest 1.x.x version.

[JohnyDays]

That seems to work perfectly, thanks! If you need some more information when debugging the issue just hit me up! 👍

[harrisiirak]

@santigimeno @JohnyDays a good catch. Let me know how this is going. Thanks for the reporting @JohnyDays!

[santigimeno]

I've been looking a little into this. Changing your code to use moment with timezone information should do it:

var expression = "0 12 * * *"
var cron = require("cron-parser")
var moment = require('moment-timezone');
var currentDate = moment().tz('Europe/Lisbon');

var iterator = cron.parseExpression(expression, {currentDate:currentDate})

for (var i=0; i<40;i++) {
  console.log(iterator.next().toString());
}

[santigimeno]

For the issue itself, I have reduced the case to this. It's due to how moment.startOf() behaves. I don't know if it's a bug or it works as expected.

'use strict';

const moment = require('moment-timezone');

var m = moment(new Date('Sun Oct 30 2016 02:00:00 GMT+0200'));
console.log(m.toString(), '<-- Just 1 hour before the DST end @ Europe/Madrid');
m.add(1, 'hours');
console.log(m.toString(), '<-- DST end transition @ Europe/Madrid works correctly');
m.startOf('hour');
console.log(m.toString(), '<-- Smthing wrong?? It goes back to the previous hour');

It's output being:

Sun Oct 30 2016 02:00:00 GMT+0200 <-- Just 1 hour before the DST end @ Europe/Madrid
Sun Oct 30 2016 02:00:00 GMT+0100 <-- DST end transition @ Europe/Madrid works correctly
Sun Oct 30 2016 02:00:00 GMT+0200 <-- Smthing wrong?? It goes back to the previous hour

OTOH, if the timezone is explicitly used, it works as expected

'use strict';

const moment = require('moment-timezone');

var m = moment(new Date('Sun Oct 30 2016 02:00:00 GMT+0200')).tz('Europe/Madrid');
console.log(m.toString(), '<-- Just 1 hour before the DST end @ Europe/Madrid');
m.add(1, 'hours');
console.log(m.toString(), '<-- DST end transition @ Europe/Madrid works correctly');
m.startOf('hour');
console.log(m.toString(), '<-- Everything correct. It remains in the same hour');

It's output being

Sun Oct 30 2016 02:00:00 GMT+0200 <-- Just 1 hour before the DST end @ Europe/Madrid
Sun Oct 30 2016 02:00:00 GMT+0100 <-- DST end transition @ Europe/Madrid works correctly
Sun Oct 30 2016 02:00:00 GMT+0100 <-- Everything correct. It remains in the same hour

Thoughts? /cc @harrisiirak @mj1856

[santigimeno]

It looks like this issue: moment/moment#2749

[santigimeno]

Tentative fix #73. /cc @harrisiirak @JohnyDays