How to cache .mp4 files in Safari with workbox-webpack-plugin? - safari

Question

I'm having exactly the same issue reported at https://github.com/GoogleChrome/workbox/issues/1663 which describes an issue that occurs exclusively in Safari where mp4 videos are not rendered after being cached by the service worker.
I'm using workbox-webpack-plugin, so the instructions provided in the comment https://github.com/GoogleChrome/workbox/issues/1663#issuecomment-448755945 will not work in my case. I'm not being able to require workbox-range-requests plugin in my webpack config file and pass it to the runtime caching options because I believe this package is intended for browser usage only. My workbox config is precaching .mp4 assets and uses a network first strategy for runtime caching.
How can I setup workbox-range-requests with workbox-webpack-plugin?
EDIT: Following Jeff's answer below, I've adjusted my webpack config to the following:
new WorkboxPlugin.InjectManifest({
swSrc: serviceWorkerSrcPath,
swDest: serviceWorkerBuildPath,
importsDirectory: 'sw',
})
The build produces the following service worker:
importScripts("/_build/sw/precache-manifest.8a0be820b796b153c97ba206d9753bdb.js", "https://storage.googleapis.com/workbox-cdn/releases/3.6.2/workbox-sw.js");
workbox.precaching.precacheAndRoute(self.__precacheManifest || []);
workbox.routing.registerRoute(
/.*\.mp4/,
new workbox.strategies.CacheFirst({
cacheName: 'videos',
plugins: [
new workbox.cacheableResponse.Plugin({ statuses: [200] }),
new workbox.rangeRequests.Plugin(),
],
}),
);
If forgot to mention previously, but I've also added crossOrigin="anonymous" attribute to the video elements.
EDIT:
Repro that demonstrates it does not work as expected on Safari: https://github.com/acostalima/workbox-range-requests-mp4-demo

Answer 1

There's specific guidance for this use case in the "Serve cached audio and video" recipe in the Workbox documentation.
You can continue using the workbox-webpack-plugin, but I'd suggest using it in InjectManifest mode, which will give you control over the top-level service worker file. That will in turn make it possible to follow the recipe.
This documentation has guidance on configuring workbox-webpack-plugin in InjectManifest mode.

Answer 2

I had the same issue with Safari and managed to resolve it by removing my video from the precahe list self.__precacheManifest and instead by adding it in the service worker's install handler:
self.addEventListener('install', (event) => {
const urls = [/* videoUrl */];
const cacheName = 'videos';
event.waitUntil(caches.open(cacheName).then((cache) => cache.addAll(urls)));
});
Looking at the logs, it seemed that otherwise only the precache was used to respond to the request for the video resource and not the router.

Answer 3

Although the docs say that adding mp4s to the precache cache and then configuring the range plugin to handle precache mp4s is supposed to work, in practice, it wasn't. Removing mp4s from the precache and configuring your own video cache with the range plugin did the trick for me. Don't forget to add the crossorigin="anonymous" tag to your videos!
Here's how I did it (webpack 5, workbox 6):
// src/service-worker.js
import { CacheableResponsePlugin } from 'workbox-cacheable-response';
import { cacheNames } from 'workbox-core';
import { precacheAndRoute } from 'workbox-precaching';
import { RangeRequestsPlugin } from 'workbox-range-requests';
import { registerRoute } from 'workbox-routing';
import { CacheFirst } from 'workbox-strategies';
const allEntries = self.__WB_MANIFEST; // Injected by WorkboxWebpackPlugin at compile time
const videoEntries = allEntries.filter((entry) => entry.url.endsWith('.mp4'));
const restEntries = allEntries.filter((entry) => !entry.url.endsWith('.mp4'));
precacheAndRoute(restEntries);
const videoCacheName = `${cacheNames.prefix}-videos-${cacheNames.suffix}`;
self.addEventListener('install', (event) => {
const allVideosAddedToCache = caches.open(videoCacheName).then((videoCache) => {
const videoUrls = videoEntries.map((entry) => entry.url);
return videoCache.addAll(videoUrls);
});
event.waitUntil(allVideosAddedToCache);
});
registerRoute(
(route) => route.url.pathname.endsWith('.mp4'),
new CacheFirst({
cacheName: videoCacheName,
plugins: [new CacheableResponsePlugin({ statuses: [200] }), new RangeRequestsPlugin()],
})
);
// webpack.config.js
plugins: [
new WorkboxWebpackPlugin.InjectManifest({
swSrc: 'src/service-worker.js',
}),
]
// index.tsx
if ('serviceWorker' in navigator) {
window.addEventListener('load', () => {
navigator.serviceWorker.register('/service-worker.js');
});
}