javascript: how to use generators as class methods

Question

My class looks like this:

class Test {
  constructor() {

  }

  *test() {
    console.log('test');
    let result = yield this.something();
    return result;
  }

  something() {
    console.log('something');
    return new Promise((resolve, reject) => {
      resolve(2);
    });
  }
}

But when I create an object from Test and call the test() method, I don't get the expected result ...

let test = new Test();
console.log(test.test()); // {}

Thought it would return 2.

Logs aren't shown as well.

What am I doing wrong here?

Answer 1

It works properly. You need to call next() on returned value by test method.

let test = new Test();
console.log(test.test().next());

Output

test
something
{ value: Promise { 2 }, done: false } 

By calling test.test() you are creating new generator instance. Then you should call next() function on created instance to make generator yield value.