error handling

[ks-s-a]

Hello.

Is there a way to catch an error during the cronjob execution? As I see cron.start() doesn't return promise, so we can't just hang a .catch() there.

I guess it's common need so some people found a good approach to solve it.

Thank you a lot!

Feature specification: https://github.com/kelektiv/node-cron/issues/426#issuecomment-1741837777

[magician11]

This is important.

If an error is thrown by a async function inside the cronjob callback.. then even with a try.. catch I will get

(node:8637) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 1)

[ncb000gt]

Currently there isn't a way. But, I do see value in this. If I get some time I'll implement this, otherwise I'd happily review a PR for this.

Thanks for bringing it up.

[tbasim]

Any updates on this?

[sathisa]

any update on this?

[chrisbrocklesby]

This would be VERY handy.... +1

[thiagodpf]

The palliative solution I found was to retrieve the CronJob callback list (job._callbacks) and for each spawn object (child_process) within it, add an handler to the spawn 'error' event, so I can at least be notified that something has gone wrong in the child_process ...

var job = new CronJob(/* parameters for the constructor */);

/* In practice you will only have one spawn to execute at each tick */
job._callbacks.forEach((spawn) => {
    spawn.on('error', (err) => {
        console.error('Failed to start subprocess.');
    });
});

You can do the same gambling on job.onComplete, as it turns into a spawn after all.

I am not proud to share this tip, but as long as there is no other solution, it goes anyway.

[NiekBeijloos]

What is the status of this feature? I noticed throwing an exception from the callback function given to cron.schedule will not terminate the overall process, but it just keeps executing. Does the node cron module apply a try catch under the hood or how can this behavior be explained?

[sheerlox]

this feature's scope seems simple and well-defined enough:

• add an optional parameter to CronJob to provide an error-handling function
• catch any error happening in the callbacks (even if no error-hander was provided)
• if an error handler was provided, call it with the error

[JosephVoid]

Hi @sheerlox @ncb000gt, I would like to add this feature.

[sheerlox]

related issue:

• https://github.com/nestjs/schedule/issues/440