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Serwist.

A Swiss Army knife for service workers.

npm install -D serwist @serwist/build

Dead simple. You need as much as ten lines of code to get started.

import { Serwist } from "serwist";

const serwist = new Serwist({
  precacheEntries: self.__SW_MANIFEST,
  skipWaiting: true,
  clientsClaim: true,
});

serwist.addEventListeners();

Customizable. Just do it your way.

import type { PrecacheEntry, SerwistGlobalConfig } from "serwist";
import { Serwist } from "serwist";
import { defaultCache } from "@serwist/vite/worker";

declare global {
  interface WorkerGlobalScope extends SerwistGlobalConfig {
    // Change this attribute's name to your \`injectionPoint\`.
    // \`injectionPoint\` is an InjectManifest option.
    // See https://serwist.pages.dev/docs/build/configuring
    __SW_MANIFEST: (PrecacheEntry | string)[] | undefined;
  }
}

declare const self: ServiceWorkerGlobalScope;

const serwist = new Serwist({
  // A list of URLs that should be cached. Usually, you don't generate
  // this list yourself; rather, you'd rely on a Serwist build tool/your framework
  // to do it for you. In this example, it is generated by \`@serwist/vite\`.
  precacheEntries: self.__SW_MANIFEST,
  // Options to customize how Serwist precaches the URLs.
  precacheOptions: {
    // Whether outdated caches should be removed.
    cleanupOutdatedCaches: true,
    concurrency: 10,
    ignoreURLParametersMatching: [],
  },
  // Whether the service worker should skip waiting and become the active one.
  skipWaiting: true,
  // Whether the service worker should claim any currently available clients.
  clientsClaim: true,
  // Whether navigation preloading should be used.
  navigationPreload: false,
  // Whether Serwist should log in development mode.
  disableDevLogs: true,
  // A list of runtime caching entries. When a request is made and its URL match
  // any of the entries, the response to it will be cached according to the matching
  // entry's \`handler\`. This does not apply to precached URLs.
  runtimeCaching: defaultCache,
  // Other options...
  // See https://serwist.pages.dev/docs/serwist/core/serwist
});

serwist.addEventListeners();

Interoperable. The Serwist API. The Service Worker API. It doesn't matter.

import type { PrecacheEntry, SerwistGlobalConfig } from "serwist";
import { BackgroundSyncQueue, Serwist } from "serwist";
import { defaultCache } from "@serwist/vite/worker";

declare global {
  interface WorkerGlobalScope extends SerwistGlobalConfig {
    __SW_MANIFEST: (PrecacheEntry | string)[] | undefined;
  }
}

declare const self: ServiceWorkerGlobalScope;

self.skipWaiting();

self.addEventListener("activate", () => self.clients.claim());

const queue = new BackgroundSyncQueue("myQueueName");

const serwist = new Serwist({
  precacheEntries: self.__SW_MANIFEST,
  precacheOptions: {
    cleanupOutdatedCaches: true,
    concurrency: 10,
    ignoreURLParametersMatching: [],
  },
  skipWaiting: false,
  clientsClaim: false,
  navigationPreload: false,
  disableDevLogs: true,
  runtimeCaching: defaultCache,
});

self.addEventListener("fetch", (event) => {
  const url = new URL(event.request.url);
  // For "/legacy-post" with the method "POST", this simply makes a network request,
  // but if that fails due to a network problem, the request is added to the background
  // synchronization queue and will be retried later.
  if (event.request.method === "POST" && url.origin === location.origin && url.pathname === "/legacy-post") {
    const backgroundSync = async () => {
      try {
        const response = await fetch(event.request.clone());
        return response;
      } catch (error) {
        await queue.pushRequest({ request: event.request });
        return Response.error();
      }
    };
    event.respondWith(backgroundSync());
  }
});

serwist.addEventListeners();