const fs = require('node:fs');
const vm = require('node:vm');
const path = require('node:path');
module.exports = function createLoader(globals, mocks = {}) {
  const modules = new Map();
  function load(file) {
    file = path.resolve(file);
    if (modules.has(file)) return modules.get(file).exports;
    const module = { exports: {} };
    modules.set(file, module);
    vm.runInNewContext(fs.readFileSync(file, 'utf8'), {
      ...globals, module, exports: module.exports,
      require(name) {
        if (mocks[name]) return mocks[name];
        if (!name.startsWith('.')) return require(name);
        const resolved = path.resolve(path.dirname(file), name);
        return load(path.extname(resolved) ? resolved : resolved + '.js');
      }
    }, { filename: file });
    return module.exports;
  }
  return load;
};