Error on stack exhaustion contains massive Node backtrace in .message element

[rrthomas]

When I cause fontoxpath to exhaust the Node.js stack (not fontoxpath's fault!), the error returned to my code contains the Node backtrace in the .message element. I wish it did not, as there's no easy way for me to avoid printing it while still printing the actual error (which would contain a long XQuery backtrace: not great, but still, at least that's the fault of my code!).

I am running with debug: false.

[rrthomas]

To put the problem another way, I get the same voluminous output if I console.log(error.message) as if I console.log(error).

[DrRataplan]

Hey Reuben,

Oof, that sounds annoying. How would you repro this? is it something like this?

var fontoxpath = require("fontoxpath")

try {
fontoxpath.evaluateXPathToString('(1 to 100000)!(. to 100000) => sum()')
} catch (e) {
console.log('ERROR', e);
}

or are custom functions involved?

[rrthomas]

In my case it used a custom function, but I think a function that always recurses would do it. I'll look when I have a moment!

[rrthomas]

The example you give results in Node.js heap exhaustion, not XQuery stack exhaustion. That causes Node.js itself to crash; not a lot you can do here!

Here's an example that gives a short (if still unhelpful) backtrace, with a user-defined function:

import fontoxpath from 'fontoxpath'

try {
  fontoxpath.evaluateXPathToString(`
  declare function local:foo() {
    local:foo()
  };
  local:foo()
  `, undefined, undefined, undefined, {language: fontoxpath.evaluateXPath.XQUERY_3_1_LANGUAGE})
} catch (e) {
  console.log('ERROR', e);
}

[rrthomas]

I suspect that the long node backtrace requires a custom function implemented in JavaScript.