Promises & then/catch

Promise.resolve(value)
  .then(result => {
    return Promise.resolve(newValue);
  })
  .then(value => console.log(value));

It creates nested Promise chains
The Promise is automatically unwrapped
When returning a Promise from then(), it's automatically unwrapped: 1) The next then() waits for the inner Promise to settle, 2) The resolved value of the inner Promise becomes the value for the next then(), 3) This enables flat Promise chains instead of nested ones, 4) Helps avoid the 'pyramid of doom' common with callbacks, 5) Allows for sequential asynchronous operations without nesting, 6) This is called Promise flattening or assimilation.
It causes a runtime error
The value is wrapped twice