是的，你可以在不使用as关键字的情况下将firestore文档转换为你想要的类型，为此你需要创建**Custom Objects Convertor**。
我在这里使用Firebase V9：

import { DocumentData, FirestoreDataConverter, QueryDocumentSnapshot, QuerySnapshot, Timestamp, collection, getDocs, query, where } from "firebase/firestore";
import { db } from "./config/firebase.js";

interface Playlist {
    name: string;
    count: number;
    isActive: boolean;
    date: Timestamp
}

const playListConverter: FirestoreDataConverter<Playlist> = {
    toFirestore(Playlist: Playlist): DocumentData {
        return Playlist;
    },
    fromFirestore(snapshot: QueryDocumentSnapshot<DocumentData>): Playlist {
        const data = snapshot.data();
        return {
            name: data.name,
            count: data.count,
            isActive: data.isActive,
            date: data.date,
        };
    },
};

let playlists : Playlist[] = []; // empty initialization

const ref = collection(db, "mocks");
const q = query(ref, where("isActive", "==", true));
const snaps: QuerySnapshot<Playlist> = await getDocs(q.withConverter(playListConverter));

snaps.forEach((doc) => {
    playlists.push(doc.data());
});

for(let playlist of playlists){
    console.log(playlist);
}

如果这感觉多余，你仍然可以使用as关键字来摆脱，如下所示：

interface Playlist {
    name: string;
    count: number;
    isActive: boolean;
    date: Timestamp
}

let playlists : Playlist[] = []

const ref = collection(db, "mocks");
const q = query(ref, where("isActive", "==", true));
const snaps = await getDocs(q);
snaps.forEach((doc) => {
    playlists.push(doc.data() as Playlist); // ⇐ still viable
});
for(let playlist of playlists){
    console.log(playlist);
}

参考：自定义对象