Custom require and resolve functions for Node.js (v.14)

index.js

// Run Node.js process with --require flag:
//   $ node index.js -r register.js
// ...or with NODE_OPTIONS env variable:
//   $ NODE_OPTIONS="-r register.js" node index.js

const style1 = require('./src/styles.less');
const style2 = require('./src/styles.less?raw');

console.log(style1, style2);

register.js

const Module = module.constructor.length > 1
  ? module.constructor
  : BuiltinModule;

const oldResolveFilename = Module._resolveFilename
Module._resolveFilename = function customResolve(request, parentModule, isMain, options) {
    let newRequest = request;
    if (/\.less\?raw$/.test(request)) {
        [ newRequest ] = request.split('?');
    }

    return oldResolveFilename.call(this, newRequest, parentModule, isMain, options)
}

const hook = function (module, file) {
    return module._compile("module.exports = {};", file);
}

require.extensions['.less'] = hook;
require.extensions['.less?raw'] = hook;