Sentry: CustomEvent captured as promise rejection

[sentry-io]

We may not be able to do anything about this, but let's figure that out. It started recently, maybe we can stop it?

Sentry Issue: REACT-COMMERCE-30M

CustomEvent: Event `CustomEvent` (type=unhandledrejection) captured as promise rejection

[rickisXP]

I'm having trouble reproducing the error, so I'm going to unassign myself. I'll post some notes below:

• Most recent events have occured on Safari, mostly mobile browser
• In all events I looked at, Sentry noted the navigation as having the same from and to link. Ex below:
  { from: /products/macbook-air-13-late-2010-2017-replacement-battery, to: /products/macbook-air-13-late-2010-2017-replacement-battery }

[masonmcelvain]

The first Sentry event happened on Aug 1, 2023 10:51:32 PDT.

#1865 (small styling change) and #1849 (update Nextjs to 13.4.12) were merged within an hour before that event.

Several unknown promise rejections stopped happening around Aug 1. This event could be a new bucket for those kinds of errors due to the framework update.

[jensbodal]

Probably related to getsentry/sentry-javascript#424

You can reproduce errors like this and have them show up in Sentry by doing something like the following in the browser console

let src = new Error({lady: 'bug'}); new Promise((resolve, reject) => {
  const script = document.createElement('script');
  script.src = src;
  script.onload = resolve;
  script.onerror = reject;
  document.body.appendChild(script);
});

I'm not familiar with your project but for issues I've seen related to this it's due to browser extensions in user's browsers.

[masonmcelvain]

Thanks for the link @jensbodal! That's a clever way to trigger Sentry events from the console, TIL.

We'll see if anything changes when we upgrade to Next.js 14, but I vote we start filtering out these errors since they chip away at our Sentry budget and they don't seem to indicate a fixable problem.

[jensbodal]

The problem seems to be it's not possible to filter them out in all cases: getsentry/sentry-javascript#9589