Internal Errors of Type Invalid Arguments/Out of Bound Array Access

[MrAshFar]

Recently, I encountered an intensive error rate (~30%) of type internal errors in my deployed worker and had no idea of the origin of these errors. After working on the issue for a couple of days and getting help from the CF team, I found that the internal errors were being thrown because of Invalid Arguments/Out Of Bound Array Access (90% accurate conclusion). I had a DataView for which I was passing incorrect arguments, new DataView(mBuffer, count * 2, 2). The count * 2 was bigger than the length of mBuffer, causing the DataView to encounter an Out of Bound Array Access. The variable count would increase over time, and when the worker was running for a long period, count would exceed the size of mBuffer, resulting in internal errors being thrown.

As the CF team suggested, I opened this issue to be sorted for future developments to add an informative js exception for such conditions.