typescript封装LocalStorage并支持过期时间

• enum ts 定义枚举

//字典 Dictionaries    expire过期时间key    permanent永久不过期
export enum Dictionaries {
    expire = '__expire__',
    permanent = 'permanent'
}

• type ts 定义类型

import { Dictionaries } from "../enum"
export type Key = string //key类型
export type expire = Dictionaries.permanent | number //有效期类型
export interface Data<T> {  //格式化data类型
    value: T
    [Dictionaries.expire]: Dictionaries.expire | number
}
export interface Result<T> { //返回值类型
    message: string,
    value: T | null
}
export interface StorageCls { //class方法约束
    set: <T>(key: Key, value: T, expire: expire) => void
    get: <T>(key: Key) => Result<T | null>
    remove: (key: Key) => void
    clear: () => void
}

• index.ts 主要逻辑实现

import { StorageCls, Key, expire, Data,Result } from "./type";
import { Dictionaries } from "./enum";
export class Storage implements StorageCls {
    //存储接受 key value 和过期时间 默认永久
    public set<T = any>(key: Key, value: T, expire: expire = Dictionaries.permanent) {
    //格式化数据
        const data = {
            value,
            [Dictionaries.expire]: expire
        }
        //存进去
        localStorage.setItem(key, JSON.stringify(data))
    }

    public get<T = any>(key: Key):Result<T | null> {
        const value = localStorage.getItem(key)
        //读出来的数据是否有效
        if (value) {
            const obj: Data<T> = JSON.parse(value)
            const now = new Date().getTime()
            //有效并且是数组类型 并且过期了 进行删除和提示
            if (typeof obj[Dictionaries.expire] == 'number' && obj[Dictionaries.expire] < now) {
                  this.remove(key)
                  return {
                     message:`您的${key}已过期`,
                     value:null
                  }
            }else{
            //否则成功返回
                return {
                    message:"成功读取",
                    value:obj.value
                }
            }
        } else {
           //否则key值无效
            console.warn('key值无效')
            return {
                message:`key值无效`,
                value:null
             }
        }
    }
    //删除某一项
    public remove(key:Key) {
        localStorage.removeItem(key)
    }
    //清空所有值
    public clear() {
       localStorage.clear()
    }
}

• rollup.js

import ts from 'rollup-plugin-typescript2'
import path from 'path'
import {fileURLToPath} from 'url'
const metaUrl = fileURLToPath(import.meta.url)
const dirName = path.dirname(metaUrl)
export default {
    input:'./src/index.ts',
    output:{
        file:path.resolve(dirName,'./dist/index.js')
    },
    plugins:[
        ts()
    ]
}