Domain is pinned to rejected Promise, but domain is not caught

[ORESoftware]

Using this code:

const Domain = require('domain');
const d = Domain.create();

process.once('unhandledRejection', function(r, p){
  console.log('unhandledRejection', r, p);
});

d.once('error', function(){
  console.log('domain caught');
});


d.run(function(){
  Promise.resolve(null).then(function(){
    throw 'foo';
  });
});

the domain error event handler won't be touched -> the exception will be sent to the unhandledRejection handler, but the promise will have the domain instance pinned to it. I assume this is expected behavior, but since we have the domain, why not fire it's error event instead of firing unhandledRejection?

[benjamingr]

Because that's not how promises with domains work - the error handling model is still promises.

Thanks for the question.

[misterdjules]

@ORESoftware

See https://nodejs.org/api/domain.html#domain_domains_and_promises:

Note that domains will not interfere with the error handling mechanisms for Promises, i.e. no error event will be emitted for unhandled Promise rejections.

[ORESoftware]

Alrighty, I can see why that decision was made, and I am glad that I can access the domain instance, I was just curious if it was expected behavior. Thanks all.