firebase-functions-auth

Small library for the Firebase Cloud Functions to validate and parse user made as an Express middleware

Install

1npm i -S firebase-functions-auth

Example

Cloud functions side

1import * as functions from 'firebase-functions';
2import * as admin from "firebase-admin";
3import * as express from "express";
4import * as cors from "cors";
5import * as cookieParser from "cookie-parser";
6import {validateFirebaseIdToken, WithUser} from "firebase-functions-auth";
7
8admin.initializeApp();
9const app = express();
10
11// Automatically allow cross-origin requests
12app.use(cors({origin: true}));
13app.use(cookieParser());
14app.use(validateFirebaseIdToken({ enableLogs: true }));
15
16app.post('/testFn', (req: express.Request & WithUser, res) => {
17  const userId = req.user ? req.user.uid : "";
18  // user id and other user data now is available here 
19
20  res.status(200).json({status: "error", userId, user: req.user})
21});

Frontend client side

1
2// Example of the function to perform requests
3
4type UserInterface = { idToken: string }
5export const fetchRequest = (user: UserInterface, url: string, method: string) => fetch(`https://europe-west1-casefolio-live.cloudfunctions.net${url}`, {
6  method: method, // *GET, POST, PUT, DELETE, etc.
7  mode: 'cors',
8  cache: 'no-cache', // *default, no-cache, reload, force-cache, only-if-cached
9  // credentials: 'same-origin', // include, *same-origin, omit
10  headers: {
11    'Content-Type': 'application/json',
12    'Authorization': `Bearer ${user.idToken}`,
13  },
14}).then((result) => {
15  if (result.status === 403) {
16    return {status: "error", message: "Unauthorized. Please refresh the page and try again."}
17  }
18  return result.json();
19})
20  .then((res) => {
21    if (res.status === "error") {
22      let message = "Unable to perform the action";
23      if (res.message) {
24        message += `: ${res.message}`;
25        if (res.message.startsWith("Unauthorized")) {
26          message = res.message;
27        }
28      }
29      throw new Error(message)
30    }
31    return res;
32  });
33
34// Example call
35fetchRequest({ idToken: "blabla"}, `/testFn`, "POST").then((res) => {
36  console.log("Success", { res });
37}).catch((e) => {
38  console.error("Error: " + e.message)
39})
40
41// Aquiring idToken
42import fb from "@firebase/app";
43import "@firebase/auth";
44import {FirebaseAuth, User} from "@firebase/auth-types";
45
46const auth: FirebaseAuth = (fb as any).auth();
47
48auth.onAuthStateChanged(async (fireUser: User | null) => {
49  if (fireUser) {
50    const idToken = await fireUser.getIdToken();
51    // here it is
52    console.log("idToken", { idToken });
53  }
54})