Old browsers cause [object Event] to be logged

[asbjornu]

Just as described in this thread on Stack Overflow, certain events sent to window.onerror will cause [object Event] to be logged as the message and not much else. It would be neat if Sentry could detect these ancient Event objects and dig out some details from them so what is logged to Sentry is something intelligible we can act upon and attempt to fix.

[asbjornu]

One particular sample from our logs show the following information:

• Browser: Dolfin 3.0
• Device: Samsung GT-S8600
• OS: Bada 2.0

[benvinegar]

I can verify that the Android browser from Android 4.1 through 4.4, seemingly from 3rd-party Android phones (e.g. Samsung, HTC) are similarly affected by this issue. I cannot confirm if Nexus phones are affected.

[bnjmnt4n]

This would be a great feature to get, and it doesn't seem relatively difficult to implement. Perhaps a quick check if message.toString() == '[object Event]' and then a for-in loop to access properties of the event object. This would be great in helping debug issues with a site in Android 4.1 - 4.4.

[benvinegar]

@D10 – I've experimented with that, but I can't find a real browser to verify that it works. I've tried emulating Android 4.1 – 4.4 on BrowserStack and using the stock Android browser, but they report errors just fine.

[Morpho]

That would be a great feature! We have the same problems with old browsers!

[sonthonaxrk]

This was driving me crazy so I wrote a patch for this https://github.com/rollokb/raven-js/tree/feat/old-webkit-Event-handling

I'm going to test it out in production for a bit before submitting a pull request.

[benvinegar]

@rollokb – that commit looks great. Let me know how it goes in production; I'd be glad to merge it into master afterwards.

[Morpho]

Great! It is driving me nuts as well! +1

[sonthonaxrk]

Seems to be working fine in production.

Edit:

Seems to be working fine, but only with Events which I've trigged myself. Still getting absolutely no information about the contents of the Event.

[benvinegar]

Seems to be working fine, but only with Events which I've trigged myself. Still getting absolutely no information about the contents of the Event.

The problem is likely here:

+        for (var property in event) {
+            if (event.hasOwnProperty(property)) {
+                options.extra[property] = event[property];
+            }
+         }

By checking hasOwnProperty, you're not going to get any properties that derive from Event.prototype. Unless these affected browsers are doing as you do in your test – placing properties directly on the Event object they create – we won't see any data.

The flip side is, if you remove that check, we're going to get a bunch of properties that have nothing to do with the error. But it might be worth seeing that that looks like.

[sonthonaxrk]

You're probably right. I was caught out by this when testing with PhantomJS.

Updated the branch
https://github.com/rollokb/raven-js/blob/feat/old-webkit-Event-handling/src/raven.js#L1109-L1121

[benvinegar]

Cool. Again, I appreciate you digging into this.