Some simple of writing iterator in javascript. Produce ce same result.

iterator.js

//Equivalence 1 : 
async function * iterableFct() {
  let i = 0;
  while (i < 2) yield ++i;
}
const iterable = iterableFct();
await iterable[Symbol.asyncIterator]().next(); // 1
await iterable[Symbol.asyncIterator]().next(); // 2

for await (const response of iterable) {
  console.log(response);
}

//Equivalence 2 : 
const iterableObject = {
  i: 0,
  async * [Symbol.asyncIterator]() {
    while (this.i < 2) yield ++this.i;
  },
};

const iterable2 = iterableObject[Symbol.asyncIterator]();
await iterable2[Symbol.asyncIterator]().next(); // 1
await iterable2[Symbol.asyncIterator]().next(); // 2
for await (const response of iterable2) {
  console.log(response);
}

//Equivalence 3 : 
const iterableObject2 = {
  i: 0,
  [Symbol.asyncIterator]() {
    return {
      next: () => {
        if (this.i < 2) {
          return { value: ++this.i, done: false };
        } else {
          return { done: true };
        }
      },
      return: () => {
        return { done: true };
      },
      [Symbol.asyncIterator]() { return this; },
    };
  },
};

const iterable3 = iterableObject2[Symbol.asyncIterator]();
await iterable3[Symbol.asyncIterator]().next();
await iterable3[Symbol.asyncIterator]().next();
for await (const response of iterable3) {
  console.log(response);
}