@uppy/golden-retriever: fix service worker (#5963)

this fixes #5945

Author: qxprakash

.changeset/new-baboons-mate.md

@@ -0,0 +1,5 @@
+---
+"@uppy/golden-retriever": minor
+---
+
+Converted sw.js to sw.ts so that it can be transpiled, in the build.

packages/@uppy/golden-retriever/package.json

@@ -4,7 +4,9 @@
   "version": "5.0.0",
   "license": "MIT",
   "type": "module",
-  "sideEffects": false,
+  "sideEffects": [
+    "lib/ServiceWorker.js"
+  ],
   "scripts": {
     "build": "tsc --build tsconfig.build.json",
     "typecheck": "tsc --build"
@@ -34,6 +36,7 @@
   ],
   "exports": {
     ".": "./lib/index.js",
+    "./lib/ServiceWorker.js": "./lib/ServiceWorker.js",
     "./package.json": "./package.json"
   },
   "dependencies": {

packages/@uppy/golden-retriever/src/ServiceWorker.js

@@ -0,0 +1,79 @@
+/// <reference lib="webworker" />
+
+declare const self: ServiceWorkerGlobalScope
+
+type StoreName = string
+type FileId = string
+type CachedStore = Record<FileId, Blob>
+type FileCache = Record<StoreName, CachedStore>
+
+const fileCache: FileCache = Object.create(null)
+
+function getCache(name: StoreName): CachedStore {
+  fileCache[name] ??= Object.create(null)
+  return fileCache[name]
+}
+
+self.addEventListener('install', (event: ExtendableEvent) => {
+  event.waitUntil(Promise.resolve().then(() => self.skipWaiting()))
+})
+
+self.addEventListener('activate', (event: ExtendableEvent) => {
+  event.waitUntil(self.clients.claim())
+})
+
+type AllFilesMessage = {
+  type: 'uppy/ALL_FILES'
+  store: StoreName
+  files: CachedStore
+}
+
+function sendMessageToAllClients(msg: AllFilesMessage): void {
+  self.clients.matchAll().then((clientList) => {
+    clientList.forEach((client) => {
+      client.postMessage(msg)
+    })
+  })
+}
+
+type AddFilePayload = { id: FileId; data: Blob }
+
+function addFile(store: StoreName, file: AddFilePayload): void {
+  getCache(store)[file.id] = file.data
+}
+
+function removeFile(store: StoreName, fileID: FileId): void {
+  delete getCache(store)[fileID]
+}
+
+function getFiles(store: StoreName): void {
+  sendMessageToAllClients({
+    type: 'uppy/ALL_FILES',
+    store,
+    files: getCache(store),
+  })
+}
+
+type IncomingMessage =
+  | { type: 'uppy/ADD_FILE'; store: StoreName; file: AddFilePayload }
+  | { type: 'uppy/REMOVE_FILE'; store: StoreName; fileID: FileId }
+  | { type: 'uppy/GET_FILES'; store: StoreName }
+
+self.addEventListener('message', (event: ExtendableMessageEvent) => {
+  const data = event.data as IncomingMessage | undefined
+  switch (data?.type) {
+    case 'uppy/ADD_FILE':
+      addFile(data.store, data.file)
+      break
+    case 'uppy/REMOVE_FILE':
+      removeFile(data.store, data.fileID)
+      break
+    case 'uppy/GET_FILES':
+      getFiles(data.store)
+      break
+    default:
+      throw new Error(
+        `[ServiceWorker] Unsupported event.data.type. Got: ${(data as any)?.type}`,
+      )
+  }
+})