[BUG] Info from Hooks.onError getting lost

[Ethaks]

Describe the bug
Having libWrapper active changes contents of errors logged via Hooks.onError, leading to error information being removed.

To Reproduce
Run the following snippet in a console:

try {
  const foo = null;
  foo.bar = false;
} catch (e) {
  Hooks.onError("Test function", e, {
    msg: "Something's wrong",
    log: "error",
  });
}

Expected behavior
The expected error message by default Foundry looks like this (i.e. includes the msg given to Hooks.onError):

Screenshots
The error with libWrapper active looks like this:

Technical Details (please complete the following information):

• LibWrapper Version 1.12.11.0
• FoundryVTT Version 10.291
• Browser & Version Chrome 108

[ruipin]

LibWrapper wraps Hooks.onError to add the list of affected packages to the error. This is probably a bug with that piece of code. I'll take a look once I'm back home on Monday.

Thanks for the report, I was unaware of this difference in behaviour!

[ruipin]

This seems to occur in Chrome anytime something causes the error to generate the corresponding stack message (in the stack property). Once that happens, the stack trace (which is what is displayed to the user) permanently copies the current error message, so any future modifications of the message will not be reflected in the stack trace.

Chrome delays generating the stack trace until someone reads it. LibWrapper reads this property to parse the package list, causing the stack to be generated before the Something's wrong message is prepended to the error message.

You can reproduce this without libWrapper by setting a breakpoint in the onError function, before msg is prepended to error.message. In such a case, the browser debugger causes error.stack to be generated with the improper message.

Firefox instead implements error.stack as an accessor that dynamically prepends the error message to the generated stack whenever accessed, meaning that this issue does not exist there. It affects solely Chrome (and Chromium).

I'll see if I can implement a workaround to avoid libWrapper causing it, but technically it is not a libWrapper bug, just a limitation of how Javascript exception messages are handled by Chrome.

[ruipin]

Workaround added in v1.12.12.0.

The message now shows correctly on both Chrome/Chromium and Firefox.

Closing issue.