Service Worker (Workbox) isn't delegating routes to our SPA on reload

Question

We're building a SPA for an internal application at work, specifically we're building a PWA that is supposed to be offline-first.

At the moment, we're doing just fine when someone reloads the page from the / route. But any other route causes the app to dinosaur, and I have no idea why.

In our service worker we just have

importScripts("/precache-manifest.cce3b8ef68b2862904ee55d44aac3447.js", "https://storage.googleapis.com/workbox-cdn/releases/3.6.3/workbox-sw.js");

workbox.precaching.precacheAndRoute(self.__precacheManifest || []);

And then a sync script for pushing local work to the backend.

In the SPA itself, we're using react and react-router. In the root of the application we have the following routes:

<Switch>
  <Route path="/_utils" component={DexUtils} />
  <Route path="/callback" component={Callback} />
  <Route exact path="/login" component={loginHandler} />
  <Route path="/" component={App} />
</Switch>

So, what happens is the last route should capture anything that isn't 1 of the other 3 routes.

The service worker, if I'm not mistaken should work without issue, but like I said, every time we reload the page from a route that isn't /, we lose connection and the app becomes unusable until you navigate back to /.

Edit: Here's the service worker register script:

/* eslint-disable */
// In production, we register a service worker to serve assets from local cache.

// This lets the app load faster on subsequent visits in production, and gives
// it offline capabilities. However, it also means that developers (and users)
// will only see deployed updates on the "N+1" visit to a page, since previously
// cached resources are updated in the background.

// To learn more about the benefits of this model, read...
// This link also includes instructions on opting out of this behavior.

const isLocalhost = Boolean(
  window.location.hostname === 'localhost' ||
    // [::1] is the IPv6 localhost address.
    window.location.hostname === '[::1]' ||
    // 127.0.0.1/8 is considered localhost for IPv4.
    window.location.hostname.match(
      /^127(?:\.(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)){3}$/
    )
);

export default function register() {
  if (process.env.NODE_ENV === 'production' && 'serviceWorker' in navigator) {
    // The URL constructor is available in all browsers that support SW.
    const publicUrl = new URL(process.env.PUBLIC_URL, window.location);
    if (publicUrl.origin !== window.location.origin) {
      // Our service worker won't work if PUBLIC_URL is on a different origin
      // from what our page is served on. This might happen if a CDN is used to
      // serve assets; see https://github.com/facebookincubator/create-react-app/issues/2374
      return;
    }

    window.addEventListener('load', () => {
      const swUrl = `${process.env.PUBLIC_URL}/service-worker.js`;

      if (isLocalhost) {
        // This is running on localhost. Lets check if a service worker still exists or not.
        checkValidServiceWorker(swUrl);

        // Add some additional logging to localhost, pointing developers to the
        // service worker/PWA documentation.
        navigator.serviceWorker.ready.then(() => {
          console.log(
            'This web app is being served cache-first by a service ' +
              'worker. To learn more, visit ...'
          );
        });
      } else {
        // Is not local host. Just register service worker
        registerValidSW(swUrl);
      }
    });
  }
}

function registerValidSW(swUrl) {
  navigator.serviceWorker
    .register(swUrl)
    .then(registration => {
      registration.onupdatefound = () => {
        const installingWorker = registration.installing;
        installingWorker.onstatechange = () => {
          if (installingWorker.state === 'installed') {
            if (navigator.serviceWorker.controller) {
              // At this point, the old content will have been purged and
              // the fresh content will have been added to the cache.
              // It's the perfect time to display a "New content is
              // available; please refresh." message in your web app.
              console.log('New content is available; please refresh.');
            } else {
              // At this point, everything has been precached.
              // It's the perfect time to display a
              // "Content is cached for offline use." message.
              console.log('Content is cached for offline use.');
            }
          }
        };
      };
    })
    .catch(error => {
      console.error('Error during service worker registration:', error);
    });
}

function checkValidServiceWorker(swUrl) {
  // Check if the service worker can be found. If it can't reload the page.
  fetch(swUrl)
    .then(response => {
      // Ensure service worker exists, and that we really are getting a JS file.
      if (
        response.status === 404 ||
        response.headers.get('content-type').indexOf('javascript') === -1
      ) {
        // No service worker found. Probably a different app. Reload the page.
        navigator.serviceWorker.ready.then(registration => {
          registration.unregister().then(() => {
            window.location.reload();
          });
        });
      } else {
        // Service worker found. Proceed as normal.
        registerValidSW(swUrl);
      }
    })
    .catch(() => {
      console.log(
        'No internet connection found. App is running in offline mode.'
      );
    });
}

export function unregister() {
  if ('serviceWorker' in navigator) {
    navigator.serviceWorker.ready.then(registration => {
      registration.unregister();
    });
  }
}

Answer 1

Assuming that your service worker is at the root of your domain /service-worker.js, you may just need to add a navigation route.

https://developers.google.com/web/tools/workbox/modules/workbox-routing#how_to_register_a_navigation_route

Answer 2

Those using generateSW can use the navigateFallback option like so:

workbox-config.js

module.exports = {
  "navigateFallback": "index.html",
  "globDirectory": "build-client/",
  "globPatterns": [
    "**/*.{js,json,png,html,txt}"
  ],
  "swDest": "build-client/sw.js"
};