local-storage-expiry.ts

import * as moment from "moment";

interface StorageObj {
    expiry: moment.Moment;
}

export class LocalS {

    save(key: string, data: any) {
        let obj;
        const expiryObj = { expiry: moment().add(7, "days") };
        obj = data instanceof Object ? { ...data, ...expiryObj } : { value: data, ...expiryObj };
        const dataString = JSON.stringify(obj);
        localStorage.setItem(key, dataString);
        return Promise.resolve();
    }

    load(key: string) {
        const dataString = localStorage.getItem(key);
        return new Promise((resolve) => {
            if (dataString) {
                const dataObj: StorageObj = JSON.parse(dataString);
                if (dataObj.expiry && moment(dataObj.expiry).isAfter(moment())) {
                    delete dataObj.expiry;
                    resolve(dataObj);
                }
            }
            resolve();
        });
    }
}