Obscure error message when javascipt module path is not found.

[peekjef72]

Unfortunately, encountering an error like this:

ts=2026-06-16T19:20:27.785Z level=error caller=httpapi_exporter.go(main.main):155 msg="Error creating exporter: NewMetricFamily(): value of 'values' for metric \"duration\": field js code  endtimestamp - starttimestamp is invalid: Invalid module"

This obscure message appears when executing JavaScript code that uses the Veeam module, which should have been loaded by the modules directive in the profile.
In practice, it means the module was not loaded... so there’s an access issue with the file funcs/veeam.js.
This is one of the points that needs improvement in the current version.

check the profiles/veeam_profiles.yml: (below the original value)

veeam:
  modules:
    # WARNING: ./ at start of the module path is mandatory; else registry looks for the module in 'node_js' directory!
    # so path is absolute or ./path
    veeam: './config/veeam/profiles/funcs/veeam.js'
  scripts:
...

Originally posted by @peekjef72 in #14

[peekjef72]

Needs to be fixed:

• Either by adding implicit code during loading:

  if ([module_name] === undefined) {
    console.error('module not loaded: check path or syntax error.');
  }

  • Verify behavior if the module contains incorrect code.

• Or in the profile's ping script: check if the module exists and, if not defined, exit with an error without executing the ping script.
  How to exit the ping script?