如果T是string | undefined，则不需要json解析，而是返回字符串本身。我该如何实施？

import { useEffect, useState, Dispatch, SetStateAction } from 'react'

type SetValue<T> = Dispatch<SetStateAction<T>>

export default function useLocalStorage<T>(
    key: string,
    fallbackValue: T
): [T, SetValue<T>] {
    const [value, setValue] = useState<T>(() => {
        console.log('key', key)
        if (typeof localStorage !== 'undefined') {
            const stored = localStorage.getItem(key)
            console.log('stored', stored)
            return stored ? JSON.parse(stored) : fallbackValue // <-- here
        } else {
            return fallbackValue
        }
    })

    useEffect(() => {
        if (typeof localStorage !== 'undefined' && value) {
            localStorage.setItem(key, JSON.stringify(value))
        }
    }, [key, value])

    return [value, setValue]
}