firebase.firestore() is not a function when trying to initialize Cloud Firestore

Question

When I try to initialize Firebase Cloud Firestore, I ran into the following error:

Uncaught TypeError: WEBPACK_IMPORTED_MODULE_0_firebase

Answer 1

First, make sure you have latest version of firebase:

npm install firebase@4.12.0 --save

Next, add both firebase and firestore:

const firebase = require("firebase");
// Required for side-effects
require("firebase/firestore");

Initialize the firebase app:

firebase.initializeApp({
  apiKey: '### FIREBASE API KEY ###',
  authDomain: '### FIREBASE AUTH DOMAIN ###',
  projectId: '### CLOUD FIRESTORE PROJECT ID ###'
});

// Initialize Cloud Firestore through Firebase
var db = firebase.firestore();

source: https://firebase.google.com/docs/firestore/quickstart?authuser=0