fix: handle Promise.reject case of Sentry.flush in with-sentry example

[natterstefan]

Note

It took me hours to figure out why I was getting an "Internal Server Error" when I added Sentry to our Next-Vercel setup based on "with-sentry".

I prepared examples in my demo repo here: natterstefan/next-with-sentry#2 with one deployment with and one without the try/catch.

The with-sentry example does not handle the case when Sentry.flush returns a rejected Promise. I was not aware of that as well until I read getsentry/sentry-javascript#3691 (comment).

In my opinion, one problem lies in the description of Sentry.flush:

If you provide a timeout and the queue takes longer to drain the promise returns false
(src)

I did not think of handling Promise.reject when I read the docs of Sentry.flush. 😅 That took some time to figure that out.

The maintainers of @sentry/nextjs use try/catch as well -> getsentry/sentry-javascript@6c1b4bd.

---

FTR: So this fixes the example, but it does not fix the issue why Sentry.flush throws an error/rejects. 🤔

Edit: There are comments mentioning the issue with Sentry.flush: getsentry/sentry-javascript#3643 (comment), and getsentry/sentry-javascript#3746. Let's see if they handle it (announced here) or not.

Documentation / Examples

• Make sure the linting passes

[lobsterkatie]

So this fixes the example, but it does not fix the issue why Sentry.flush throws an error/rejects

Hi, @natterstefan. I pinged you also in one of the issues you linked, but this should be fixed in getsentry/sentry-javascript#3846. Also, getsentry/sentry-javascript#3811 fixed the await issue with flush.

In fact, everything shown in your example, including capturing the exception, is handled by withSentry and shouldn’t have to be done manually anymore (see the bottom code snippet here).

Cheers!

[natterstefan]

Hi @lobsterkatie,

I am sorry it took me some time to answer. Thanks for getting back to me. I tested it with "@sentry/nextjs": "6.13.2" and I can confirm that it works (both with the latest next@10 but also next@11 (as of today) on Vercel.

Thanks a lot for taking care of that!

[natterstefan]

Closed, see #26767 (comment) for more details.