Why return with parentheses in the same line works but parentheses in a new line does not?

Question

Why in javascript a return with parentheses at the same line works but return undefined when parentheses is at a new line ?

this one works

addOne = (i) => {
  return (
    i + 1
  );
}

but this one return undefined

addOne = (i) => {
  return 
  (
    i + 1
  );
}