How to handle errors thrown from defineCommand / defineEvent handlers?

Hi! For example:

export = domain.defineEvent({},  (data, aggregate) => {
    aggregate.set('balance', data.balance);
    aggregate.set('value', data.value);

    throw new FakeError(); // unhandled, something went wrong or TypeError
});

how to handle such type of errors?

Approach listed below doesn’t help.

    async handle(data: object) {
        return new Promise((resolve, reject) => {
            try {
                this.domain.handle(data, (err) => {
                    if (err) {
                        reject(err);
                    } else {
                        resolve();
                    }
                });
            } catch (e) {
                reject(e);
            }
        });
    }

This problem is similar for defineViewBuilder of eventdenormalizer. Can’t catch errors there too.

another a little question: Why custom command handler is so bad?

Command Handler (Be careful!!!)
Is your use case not solvable without a custom command handling? Sagas? Micro-Services?

what if I need to make external operation like 3rd party API http call and generate event with resulted data without saving to eventstore. This event then can be handled by sagas to generate command to update required aggregate.

[imissyouso]

Always happy for a PR.

currently we are at stage of investigating and collecting potential issues before the real start of development. As soon as we will do it wait PR from us 😃

[adrai]

Always happy for a PR.