Capturing CORS Errors

[Pekito]

Is it possible to capture CORS errors automatically? I want to be able to check when scripts/image requests from my site throw CORS related errors

[AbhiPrasad]

As per the cors errors docs

Note: For security reasons, specifics about what went wrong with a CORS request are not available to JavaScript code. All the code knows is that an error occurred. The only way to determine what specifically went wrong is to look at the browser's console for details.

This means we can't programmatically capture when cors errors occur. What we can instead do is to use the CaptureConsole integration to send console warnings/errors to Sentry. Note that you might have to add some preemptive filtering if you have a noisy console.

EDIT: My above comment is incorrect, you don't have access to CORS errors programmatically from the browser.

[gnoyixiang]

@AbhiPrasad hey I just came across this thread which says CaptureConsole does not actually pick up CORS errors. I have also tested it out on my application, and the console logs for CORS errors are not reflected on the sentry dashboard. Are there other solutions to capture CORS errors using Sentry?

[AbhiPrasad]

Yes sorry my initial answer was mistaken, and I have made an edit.

Are there other solutions to capture CORS errors using Sentry?

Nope, not specifically to CORS errors. You can turn on the optional HTTPClient integration to capture errors on failed fetch/xhr requests, but that creates sentry issues for all network errors, not just CORS ones.