How to use Web worker in cubejs?

[Aaron-Bird]

The following examples all throw errors:
Where did I go wrong? 1

const randomCube = Cube.random();
Cube.asyncInit('./lib/worker.js', function () {
  // Cannot read property '24092' of null
  console.log(randomCube.solve());
});

2

const randomCube = Cube.random();
Cube.asyncInit('./lib/worker.js', function () {
    //cube.toJSON is not a function
    Cube.asyncSolve(randomCube, function (algorithm) {
        console.log(algorithm);
    });
});

I wrote a demo here: https://github.com/Aaron-Bird/cubejs-demo