How to resolve requires without `.js` extension in a very basic NPM resolver?

I have an NPM resolver that without caching that expects everything to be in a

node_modules

node_modules

node_modules

node_modules folder, mostly copied from deno cli

https://gist.github.com/rust-play/fbd49c87332ee27b3d217bb1e0005462

I can successfully

require

require

require

require lodash, but one of the npm libraries I'm trying to require imports a babel library like so

var _interopRequireDefault = require("@babel/runtime/helpers/interopRequireDefault");

var _interopRequireDefault = require("@babel/runtime/helpers/interopRequireDefault");

var _interopRequireDefault = require("@babel/runtime/helpers/interopRequireDefault");

var _interopRequireDefault = require("@babel/runtime/helpers/interopRequireDefault");

It seems like it's failing to resolve the module, cause it panics at

thread 'main' panicked at 'called

thread 'main' panicked at 'called

thread 'main' panicked at 'called

thread 'main' panicked at 'called Result::unwrap()

 on an

on an

 on an

on an Err

 value: Error: Cannot find module '@babel/runtime/helpers/interopRequireDefault'

value: Error: Cannot find module '@babel/runtime/helpers/interopRequireDefault'

 value: Error: Cannot find module '@babel/runtime/helpers/interopRequireDefault'

value: Error: Cannot find module '@babel/runtime/helpers/interopRequireDefault'

Gist

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