I'm not sure why you think local variable names are mattering here... What's happening is that this expresion: const { error, value } = obj; where obj is

I'm not sure why you think local variable names are mattering here... What's happening is that this expresion: const { error, value } = obj; where obj is an object will assign obj.error to error and obj.value to value. You could name your locals something else if you wanted, of course: const { error: myError, value: myValue } = obj; will assign obj.error to myError and obj.value to myValue. There just happens to be a shorter syntax for the common const { error: error, value: value } = obj; case.