I had a caveat in my original post re. the implicit wrapping of the `Promise.then()` callback's (pure) return value in a new Promise, and how this differs from Haskell's monadic bind; I had hoped to make a loose analogy while pointing out the differences for the sake of illustration. However it is indeed also possible to return a Promise from `.then()`'s callback, which is closer to Haskell's bind: [0]

    The behavior of the returned promise (call it p) depends on the handler's
    execution result, following a specific set of rules. If the handler function:

    * returns a value: p gets fulfilled with the returned value as its value.

    [...]

    * returns an already fulfilled promise: p gets fulfilled with that promise's value as its value.

... then you can obtain a solution closer to the Haskell translation by using the behaviour of the second cited bullet point from the MDN article:

    const promise1 = Promise.resolve(123);

    promise1.then(v => Promise.resolve(v * 2)).then((value) => {
      console.log(value);
      // Expected output: 246
    });

[0] https://developer.mozilla.org/en-US/docs/Web/JavaScript/Refe...