JSON Serialization error with circular reference

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Package + Version

• @sentry/browser
• @sentry/node
• raven-js
• raven-node (raven for node)
• other:

Version:

5.4.3,5.5.0

Description

When serializing an event/error that contains a circular reference, a browser error occurs, and then that error is logged, losing the original error.

Repro steps: open a console with sentry SDK loaded and initialized, run:

var obj = {};
obj.repro = obj;
Sentry.captureEvent(obj);

Logged stack trace in Sentry from the above:

TypeError
Converting circular structure to JSON
    --> starting at object with constructor 'Object'
    --- property 'repro' closes the circle
<anonymous> in JSON.stringify
../src/transports/fetch.ts in sendEvent at line 15:18
../../core/src/basebackend.ts in sendEvent at line 96:21
../../core/src/baseclient.ts in onfulfilled at line 353:32
../../utils/src/syncpromise.ts in onSuccess at line 127:21
../../utils/src/syncpromise.ts at line 86:52
<anonymous> in Array.forEach
../../utils/src/syncpromise.ts in _executeHandlers at line 86:22
../../utils/src/syncpromise.ts in _attachHandler at line 96:10
../../utils/src/syncpromise.ts in callback at line 106:12
../../utils/src/syncpromise.ts in new n at line 42:7
../../utils/src/syncpromise.ts in then at line 105:12
../../core/src/baseclient.ts in callback at line 342:46
../../utils/src/syncpromise.ts in new n at line 42:7
../../core/src/baseclient.ts in _processEvent at line 341:12
../../core/src/baseclient.ts in method at line 135:10
../../hub/src/hub.ts in _invokeClient at line 81:27
../../hub/src/hub.ts in method at line 223:10
../../minimal/src/index.ts in callOnHub at line 13:17
../../minimal/src/index.ts in Object.n.captureEvent at line 64:10
<anonymous> at line 3:8

Link to affected production issue in Sentry (my guess is that this is an error involving the Datatables JS library, not sure though): https://sentry.io/organizations/grasp-and-grow/issues/1107636848/

I see similar issues, but they seem to involve memory consumption and crashes.

[cgeorg]

We’re using the ASP.NET bundling for that, it looks like it doesn’t support source mapping out of the box. I’m trying to put together a codepen but can’t get it to trigger the same issue. Having trouble getting around CORS things with codepen to hit the exact code path - I will update if I can get a simple repro for you.

[kamilogorek]

We already do this for Events, but it requires onerror data to be in place. Here we’d have to assume that a message can be either string or this event object, which is non-standard in any format. This would simply require too much additional boilerplate to handle, and it’s the first time I see such behaviour in the wild.

It won’t be the most beautiful error report you’ll ever see, but when paired with $.fn.dataTable.ext.errMode = 'throw'; you’ll get necessary information. See: https://datatables.net/manual/tech-notes/7

Patched here: https://github.com/getsentry/sentry-javascript/pull/2302