When using Graal as the node engine in IntelliJ, IntelliJ/Eslint displays this error which is not displayed when using V8 node.

Thanks for your report!
TRegex, the regular expression engine used in graal-js, is not feature-complete yet, support for expressions such as the one mentioned here is coming soon.
Hi @oluwasayo
the problem you reported has been fixed on master. It will be part of the following GraalVM release (20.1.0).
Best, Christian
Most helpful comment
Thanks for your report!
TRegex, the regular expression engine used in graal-js, is not feature-complete yet, support for expressions such as the one mentioned here is coming soon.