What do the parentheses wrapping the object literal in an arrow function mean? [duplicate]

Answer 1

It allows you to create an expression, so

let a = () => ({ id: 'abc', name: 'xyz' })

specifies that a when invoked, returns the enclosed object

If you remove the () in this case, it will throw an error because it is not a valid function body statement, because the {} in let a = () => { id: 'abc', name: 'xyz' } are interpreted as the boundaries of a statement, but the content inside is not valid if you look at it.

let a = () => {
    id: 'abc',    /* Not valid JS syntax */
    name: 'xyz'
}