"use strict";
const fs = require('fs');
const path = require('path');

function clone(generatorFunction) {
  function callback(err) {
    if (err) {
      return generator.throw(err);
    }
    const results = [].slice.call(arguments, 1);
    generator.next(results.length > 1 ? results : results[0]); // <-- calls generator with value to continue after yield.
  }
  const generator = generatorFunction(callback);
  generator.next();  // <--- Line that triggers cloning.
}

clone(function* (callback) {
  const fileName = path.basename(__filename);
  const myself = yield fs.readFile(fileName, 'utf8', callback);
  yield fs.writeFile(`clone_of_${fileName}`, myself, callback);
  console.log('Clone created');
});