requireImpl.js

const path = require('node:path');
const fs = require('node:fs');
const assert = require('node:assert');

const requireImpl = (pth) => {
  assert((typeof pth) === 'string');
  let moduleText;
  const modulePath = path.join(process.cwd(), pth);
  try {
    moduleText = fs.readFileSync(modulePath);
  } catch (err) {
    throw new Error(`module not found ${modulePath}`)
  }
  const ctx = {
    module: {},
  };

  const fn = new Function(`Object.assign(global, this); ${moduleText}`);
  fn.bind(ctx)();

  return ctx.module.exports;
}