Sharing Types Between Server and Client

When you share your document types between your server and client code, you might run into a problem with the Timestamp type, because the web and server SDKs currently have slightly incompatible types. The web timestamp has a toJSON method which doesn't exist on the server.

The way to work around this is by using a type alias called FsTimestamp in all of your document types. Then, in each of the client-side or server-side applications, declare this type globally in a global.d.ts file.

Web

import type { Timestamp } from "firebase/firestore";

declare global {
  type FsTimestamp = Timestamp;
}

Server

import type { Timestamp } from "firebase-admin/firestore";

declare global {
  type FsTimestamp = Timestamp;
}

React Native

import type { Timestamp } from "@react-native-firebase/firestore";

declare global {
  type FsTimestamp = Timestamp;
}