feat: support debugging PWA in dev (#4853)

* feat: support enabling pwa in dev

* enable workbox debug

* add prebuild script

* fix lint

public/index.html

@@ -98,6 +98,22 @@
     />
 
     <link rel="stylesheet" href="fonts.css" type="text/css" />
+    <% if (process.env.REACT_APP_DEV_DISABLE_LIVE_RELOAD === "true") { %>
+    <script>
+      {
+        const _WebSocket = window.WebSocket;
+        window.WebSocket = function (url) {
+          if (/ws:\/\/localhost:.+?\/sockjs-node/.test(url)) {
+            console.info(
+              "[!!!] Live reload is disabled via process.env.REACT_APP_DEV_DISABLE_LIVE_RELOAD [!!!]",
+            );
+          } else {
+            return new _WebSocket(url);
+          }
+        };
+      }
+    </script>
+    <% } %>
     <script>
       window.EXCALIDRAW_ASSET_PATH = "/";
       // setting this so that libraries installation reuses this window tab.

public/service-worker.js

@@ -0,0 +1,81 @@
+// eslint-disable-next-line no-restricted-globals
+// eslint-disable-next-line no-unused-expressions
+
+/* eslint-disable no-restricted-globals */
+/* global importScripts, workbox */
+
+/**
+ * Welcome to your Workbox-powered service worker!
+ *
+ * You'll need to register this file in your web app and you should
+ * disable HTTP caching for this file too.
+ * See https://goo.gl/nhQhGp
+ *
+ * The rest of the code is auto-generated. Please don't update this file
+ * directly; instead, make changes to your Workbox build configuration
+ * and re-run your build process.
+ * See https://goo.gl/2aRDsh
+ */
+
+// in dev, `process` is undefined because this file is not compiled until build
+const IS_DEVELOPMENT =
+  typeof process === "undefined" || process.env.NODE_ENV !== "production";
+
+if (IS_DEVELOPMENT) {
+  importScripts(
+    "https://storage.googleapis.com/workbox-cdn/releases/4.3.1/workbox-sw.js",
+  );
+  workbox.setConfig({
+    debug: true,
+  });
+} else {
+  importScripts("/workbox/workbox-sw.js");
+  workbox.setConfig({
+    modulePathPrefix: "/workbox/",
+  });
+}
+
+self.addEventListener("message", (event) => {
+  if (event.data && event.data.type === "SKIP_WAITING") {
+    self.skipWaiting();
+  }
+});
+
+workbox.core.clientsClaim();
+
+if (!IS_DEVELOPMENT) {
+  workbox.precaching.precacheAndRoute(self.__WB_MANIFEST);
+
+  workbox.routing.registerNavigationRoute(
+    workbox.precaching.getCacheKeyForURL("./index.html"),
+    {
+      blacklist: [/^\/_/, /\/[^/?]+\.[^/]+$/],
+    },
+  );
+}
+
+// Cache relevant font files
+workbox.routing.registerRoute(
+  new RegExp("/(fonts.css|.+.(ttf|woff2|otf))"),
+  new workbox.strategies.StaleWhileRevalidate({
+    cacheName: "fonts",
+    plugins: [new workbox.expiration.Plugin({ maxEntries: 10 })],
+  }),
+);
+
+self.addEventListener("fetch", (event) => {
+  if (
+    event.request.method === "POST" &&
+    event.request.url.endsWith("/web-share-target")
+  ) {
+    return event.respondWith(
+      (async () => {
+        const formData = await event.request.formData();
+        const file = formData.get("file");
+        const webShareTargetCache = await caches.open("web-share-target");
+        await webShareTargetCache.put("shared-file", new Response(file));
+        return Response.redirect("/?web-share-target", 303);
+      })(),
+    );
+  }
+});