How to get TImestamp type in Firebase functions in typescript?

Question

I want to use firebase Timestamp type in a type declaration for firestore document field, but cannot figure out where I can import. Does anybody know?

My code.

import * as functions from "firebase-functions";
const admin = require('firebase-admin');

interface MyDocument {
  timestamp1: admin.firestore.Timestamp,
  timestamp2: functions.firestore.Timestamp,
}

Error in timestamp1: Cannot find namespace 'admin'.ts(2503)
Error in timestamp2: Namespace '"/path/to/project/functions/node_modules/firebase-functions/lib/providers/firestore"' has no exported member 'Timestamp'.

package.json

"dependencies": {
    ...
    "firebase-admin": "^9.5.0",
    "firebase-functions": "^3.13.1",
    ...
}

Answer 1

Here's the shorthand notation:

import * as admin from 'firebase-admin';
import Timestamp = admin.firestore.Timestamp;

Answer 2

This works for me in my Typescript project:

import * as admin from "firebase-admin";
let t : admin.firestore.Timestamp = //....