const dbRequest = <IDBOpenDBRequest>indexedDB.open("lists",1);
dbRequest.then((db:IDBDatabase) =>{
//do something with db...
},console.error);

async function XXX (){
//...config your transaction
await store.add({title:'i like f',tags:['a','b','c']},4);
//...
}

//......
dbRequest.then(async (db:IDBDatabase):Promise<boolean> =>{
    const store = db.store('favlist','readwrite');
    await store.add({title:'i like',tags:['a','b','c']},1);
    //....
}

    store.walkKeyCursor(console.log);
    // {key:xxxx,value:null}
    store.index('title').walkCursor(console.log);
    // {key:xxxx,value:xxxx}