Cloud functions for firebase can not use serverTimestamp

Question

I am currently using Cloud functions for firebase with node.js of typescript. The code is as follows

import * as functions from "firebase-functions";
import * as admin from "firebase-admin";

const endpoint = functions.region("asia-northeast1");
export const test = endpoint.https.onCall(async (req) => {
  const original = req.hotelCode;
  const writeResult = await admin
      .firestore()
      .collection("messages")
      .add({
        original: original,
        created_at: admin.firestore.FieldValue.serverTimestamp(),
      });
  console.log(writeResult);
});

The error statement is as follows.

TypeError: Cannot read property 'serverTimestamp' of undefined\n

If I comment out the serverTimestamp() line it succeeds. I didn't care about this because it's not web, but is it related to v8 or v9? The only two that are in the package are

"firebase-admin":"^11.0.1",
"firebase-functions":"^3.23.0",

It was working normally before, so I really don't understand why I am having trouble. Please help me.

Answer 1

It's really odd, but I was able to do it using.

import {FieldValue} from "firebase-admin/firestore";

I'm not sure how the version of node_module can change even though the pubspeck.lock hasn't changed, or if global was used.