Cannot read property 'name' of undefined

[spoterala]

I've got an error like in title. It's in function computeStackTrace in last return when tries to get ex.name.

It is called by function traceKitWindowOnUnhandledRejection (and I don't have more stacktrace).

Could you tell me why I got this error?

[niemyjski]

This is a function that is wired up to https://developer.mozilla.org/en-US/docs/Web/API/WindowEventHandlers/onunhandledrejection and handles this type of event. Sounds like that event can be null. Can you let us know how you reproduced it and with the specifics of what browser/os you were using with specific versions.

[spoterala]

I'm sorry, but I've seen that error only once and had some trouble getting it.

Steps to get this error:

1. Call reject() in a Promise
2. PromiseRejectionEvent is triggered
3. The event is caught by traceKitWindowOnUnhandledRejection in TraceKit
4. e.reason is undefined
5. computeStackTrace gets undefied as a first argument