使用 firebase 托管和功能的 Service Worker 注册失败

Question

Service Worker is not registered with an application builded by Nuxt.js (Universal) which is running on Firebase Functions.

I'm currently trying to build a prototype web application with Nuxt.js Universal mode and Firebase Functions. The app uses service worker with nuxt official pwa-module to manage the session of logged in user, so that the client could send the request with authorization header to the server and server would verify the user session via Firebase Authentication.

I've already tried to run it on local server with yarn run build and yarn run start , and ensured the service worker have been correctly registered and worked perfectly. However when I try to check the same operation with firebase serve , I receive following errors on the browser.

A bad HTTP response code (404) was received when fetching the script.
Failed to load resource: net::ERR_INVALID_RESPONSE
dcbac67bb39a765db27a.js:1 Service worker registration failed: TypeError: Failed to register a ServiceWorker: A bad HTTP response code (404) was received when fetching the script.

I also found that the service worker does not send the session data to the server. Exactly same thing was reproduced when I deployed source into production with firebase deploy .

It even occurs when I completely clean project with yarn create nuxt-app , yarn run build and firebase serve . "sw.js" file indicates failed status on Chrome developer tool.

I'm not sure if it is concerned but my Firebase is on Spark plan.

My project tree.

.
├── firebase.json
├── firestore.indexes.json
├── firestore.rules
├── functions
│   ├── index.js
│   ├── nuxt
│   │   ├── App.js
│   │   ├── axios.js
│   │   ├── client.js
│   │   ├── components
│   │   ├── dist
│   │   ├── empty.js
│   │   ├── index.js
│   │   ├── loading.html
│   │   ├── middleware.js
│   │   ├── router.js
│   │   ├── server.js
│   │   ├── store.js
│   │   ├── sw.plugin.js
│   │   ├── sw.template.js
│   │   ├── utils.js
│   │   └── views
│   ├── package-lock.json
│   ├── package.json
│   └── yarn.lock
├── public
└── src
    ├── assets
    ├── components
    ├── jest.config.js
    ├── layouts
    ├── middleware
    ├── nuxt.config.js
    ├── package.json
    ├── pages
    ├── plugins
    ├── server
    ├── static
    │   └── sw.js
    ├── store
    └── test
    └── yarn.lock

src/static/sw.js

importScripts('/_nuxt/workbox.4c4f5ca6.js')

workbox.precaching.precacheAndRoute([
  {
    "url": "/_nuxt/021e1640b53136b75c48.js",
    "revision": "2753e747206d803c793b59a324c1931b"
  },
  {
    "url": "/_nuxt/03c9e340d8692d1403a9.js",
    "revision": "2b882d73d20a0b2cfd318e9e05d3496e"
  },
  {
    "url": "/_nuxt/78bddfa6b6a4919b78d6.js",
    "revision": "70312f6623089e3b4aa6454120c1e177"
  },
  {
    "url": "/_nuxt/85c817abccdd40162004.js",
    "revision": "45448f8709d01af59bb125a1d06be23a"
  },
  {
    "url": "/_nuxt/8654a518d0f3e326c9a6.js",
    "revision": "a42426f5e7b458acc6fdf0e9e48c7d35"
  },
  {
    "url": "/_nuxt/95b421159066eff9e318.js",
    "revision": "efd1643042f804defa7212979867558a"
  },
  {
    "url": "/_nuxt/9b487bf2df1190b68565.js",
    "revision": "78837d0e624deccc85761b44f9ede9be"
  },
  {
    "url": "/_nuxt/ce59381752309c170d41.js",
    "revision": "d3e50bf27891c4efa6dff5076a0772a6"
  },
  {
    "url": "/_nuxt/d8fa6ae5ca14331879f6.js",
    "revision": "5da6698c9359df803243ecc44519b610"
  },
  {
    "url": "/_nuxt/dcbac67bb39a765db27a.js",
    "revision": "9505aa84ddb2a70b826d324433daff36"
  },
  {
    "url": "/_nuxt/dee89eef613849499c7f.js",
    "revision": "43117ed819efe3d00c963dd655894d5f"
  }
], {
  "cacheId": "justtest",
  "directoryIndex": "/",
  "cleanUrls": false
})

workbox.clientsClaim()
workbox.skipWaiting()

workbox.routing.registerRoute(new RegExp('/_nuxt/.*'), workbox.strategies.cacheFirst({}), 'GET')

workbox.routing.registerRoute(new RegExp('/.*'), workbox.strategies.networkFirst({}), 'GET')

functions/index.js

const functions = require("firebase-functions")
const { Nuxt } = require("nuxt")
const express = require("express")
const app = express()

const nuxt = new Nuxt({ buildDir: "nuxt", dev: false })

function handleRequest(req, res) {
  res.setHeader('Cache-Control', 'private')
  return new Promise((resolve, reject) => {
    nuxt.render(req, res, promise => {
      promise.then(resolve).catch(reject)
    })
  })
}

app.use(handleRequest)

exports.ssr = functions.https.onRequest(app)

Expected behavior is that sw.js working fine when I run the app with firebase serve and firebase deploy .

Answer 1

I managed to find the solution. I may have misunderstood the behavior of service workers.
I just leave my solution so that I could help somebody who has the same situation.

First of all, I was not aware of the service worker js file /static/sw.js at all since it is automatically created by yarn run build and everything worked fine when I run the app with yarn run start . Therefore I thought I wouldn't have to care about that file at all.

However I found out that all the files in /static directory have to be placed in /public directory, which will be hosted by firebase hosting, so that clients can find them and download them. I guess when I use yarn run start the files in /static directory would be hosted by dev server.

Also I realized that the service workers are static javascript files and they have to be hosted by firebase hosting, not by firebase functions. I once tried to place them in dist/client but it doesn't make any sense. It has to be placed in /public directory.

I finally make it work with following project tree. When I run yarn run build I copy all the contents in /src/static to /public to host them with firebase hosting.

.
├── firebase.json
├── functions
│   ├── index.js
│   ├── nuxt
│   │   ├── App.js
│   │   ├── axios.js
│   │   ├── client.js
│   │   ├── components
│   │   ├── dist
│   │   ├── empty.js
│   │   ├── index.js
│   │   ├── loading.html
│   │   ├── middleware.js
│   │   ├── router.js
│   │   ├── server.js
│   │   ├── store.js
│   │   ├── sw.plugin.js
│   │   ├── sw.template.js
│   │   ├── utils.js
│   │   └── views
│   ├── package-lock.json
│   ├── package.json
│   └── yarn.lock
├── public
│   ├── favicon.ico
│   ├── sw-firebase-auth.js
│   └── sw.js
└── src
    ├── assets
    ├── components
    ├── layouts
    ├── middleware
    ├── nuxt.config.js
    ├── package.json
    ├── pages
    ├── plugins
    ├── server
    ├── static
    │   ├── favicon.ico
    │   ├── sw-firebase-auth.js
    │   └── sw.js
    ├── store
    └── yarn.lock

This is my sw-firebase-auth.js . (I compile this script with Browserify to work.)

var firebase = require('firebase')

// Initialize the Firebase app in the service worker script.
firebase.initializeApp({
  apiKey: '*************',
  authDomain: '*************',
  databaseURL: '*************',
  projectId: '*************',
  storageBucket: '*************',
  messagingSenderId: '*************'
})

/**
 * Returns a promise that resolves with an ID token if available.
 * @return {!Promise<?string>} The promise that resolves with an ID token if
 *     available. Otherwise, the promise resolves with null.
 */
const getIdToken = () => {
  return new Promise((resolve) => {
    const unsubscribe = firebase.auth().onAuthStateChanged((user) => {
      unsubscribe();
      if (user) {
        user.getIdToken().then((idToken) => {
          resolve(idToken)
        }, () => {
          resolve(null)
        });
      } else {
        resolve(null)
      }
    })
  })
}

const getOriginFromUrl = (url) => {
  const pathArray = url.split('/');
  const protocol = pathArray[0];
  const host = pathArray[2];
  return protocol + '//' + host;
};

self.addEventListener('fetch', (event) => {
  const requestProcessor = (idToken) => {
    let req = event.request;
    if (self.location.origin == getOriginFromUrl(event.request.url) &&
        (self.location.protocol == 'https:' ||
         self.location.hostname == 'localhost') &&
        idToken) {
      const headers = new Headers();
      for (let entry of req.headers.entries()) {
        headers.append(entry[0], entry[1]);
      }
      headers.append('Authorization', 'Bearer ' + idToken);
      try {
        req = new Request(req.url, {
          method: req.method,
          headers: headers,
          mode: 'same-origin',
          credentials: req.credentials,
          cache: req.cache,
          redirect: req.redirect,
          referrer: req.referrer,
          body: req.body,
          bodyUsed: req.bodyUsed,
          context: req.context
        });
      } catch (e) {
        console.log(e)
      }
    }
    return fetch(req);
  };
  event.respondWith(getIdToken().then(requestProcessor, requestProcessor));
});

self.addEventListener('activate', event => {
  event.waitUntil(clients.claim());
})

Also this is workbox config in nuxt.conf.js . It works well with official pwa-module using importScripts .

  workbox: {
    importScripts: [
      'sw-firebase-auth.js'
    ]
  }

I hope this would help somebody.

Answer 2

Fellow Nuxt.js developers in 2020, Jun

If you are deploying Nuxt.js 2.12.2 project with SSR, you probably have .nuxt folder in your project directory. Delete that, configure Workbox from nuxt.config.js if you need and run nuxt build , npm run build or yarn build .

If it works on local machine, you can try clearing caches on server to make sure all old .nuxt folders are gone and redeploy the project.

Hope this helps ✨