Sentry fails when processing errors without a stacktrace

Do you want to request a feature or report a bug?

Bug

What is the current behavior?

I have full sourcemaps and releases are automatically uploaded to Sentry. For Sentry error reports I’m getting:

There was 1 error encountered while processing this event
Invalid location in sourcemap: (None, None)

{
  "column": null,
  "source": "https://ismaywolff.nl/work",
  "row": null
}

In Chrome my sourcemaps resolve without problems. Also on sourcemaps.io my sourcemaps validate without errors as well. I’m building full sourcemaps with columns and lines in webpack with source-map (see here), and outputting them through uglify with sourceMap: true as well.

So everything should be fine, but instead I’m getting the error above.

What is the expected behavior?

For raven-js to report the error without warnings.

• Chrome 57
• Raven-js 3.14.2
• OSX 10.12.4
• Did this work in previous versions of Raven.js: haven’t tried
• Are you using the CDN (http://ravenjs.com): yes
• Are you using hosted Sentry: hosted

[ismay]

Ok, so the problem was that the Error I was triggering to test Sentry was a fetch error. Which didn’t have a stacktrace with line numbers (as the error is created asynchronously, see here). Which meant that Sentry couldn’t refer to a particular line.

I’d say in this case Sentry or Raven are not to blame technically. But:

• A clear error message (i.e. something like: no line/column numbers found in stacktrace, or invalid stacktrace) would have saved me a lot of work. The current error is quite non-descript.
• You could just fail gracefully and state that a stacktrace couldn’t be found, so the error can’t be mapped to a specific line. And don’t display this state as being in error, as everything that happened here is still according to the js spec (i.e. errors don’t have to have a stack property).

Also, it seems weird that the error reporting is so reliant on a non-standard feature, see MDN. Maybe it would be good to warn users of this as well, as non-supporting browsers would send errors that Sentry apparently can’t process.

[kamilogorek]

Let’s move discussion to https://github.com/getsentry/raven-js/issues/1009