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diff --git a/src/templates/assets/javascripts/browser/worker/index.ts b/src/templates/assets/javascripts/browser/worker/index.ts
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+/*
+ * Copyright (c) 2016-2023 Martin Donath <martin.donath@squidfunk.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+import {
+  Observable,
+  Subject,
+  endWith,
+  fromEvent,
+  ignoreElements,
+  mergeWith,
+  share,
+  takeUntil
+} from "rxjs"
+
+/* ----------------------------------------------------------------------------
+ * Types
+ * ------------------------------------------------------------------------- */
+
+/**
+ * Worker message
+ */
+export interface WorkerMessage {
+  type: unknown                        /* Message type */
+  data?: unknown                       /* Message data */
+}
+
+/* ----------------------------------------------------------------------------
+ * Helper functions
+ * ------------------------------------------------------------------------- */
+
+/**
+ * Create an observable for receiving from a web worker
+ *
+ * @template T - Data type
+ *
+ * @param worker - Web worker
+ *
+ * @returns Message observable
+ */
+function recv<T>(worker: Worker): Observable<T> {
+  return fromEvent<MessageEvent<T>, T>(worker, "message", ev => ev.data)
+}
+
+/**
+ * Create a subject for sending to a web worker
+ *
+ * @template T - Data type
+ *
+ * @param worker - Web worker
+ *
+ * @returns Message subject
+ */
+function send<T>(worker: Worker): Subject<T> {
+  const send$ = new Subject<T>()
+  send$.subscribe(data => worker.postMessage(data))
+
+  /* Return message subject */
+  return send$
+}
+
+/* ----------------------------------------------------------------------------
+ * Functions
+ * ------------------------------------------------------------------------- */
+
+/**
+ * Create a bidirectional communication channel to a web worker
+ *
+ * @template T - Data type
+ *
+ * @param url - Worker URL
+ * @param worker - Worker
+ *
+ * @returns Worker subject
+ */
+export function watchWorker<T extends WorkerMessage>(
+  url: string, worker = new Worker(url)
+): Subject<T> {
+  const recv$ = recv<T>(worker)
+  const send$ = send<T>(worker)
+
+  /* Create worker subject and forward messages */
+  const worker$ = new Subject<T>()
+  worker$.subscribe(send$)
+
+  /* Return worker subject */
+  const done$ = send$.pipe(ignoreElements(), endWith(true))
+  return worker$
+    .pipe(
+      ignoreElements(),
+      mergeWith(recv$.pipe(takeUntil(done$))),
+      share()
+    ) as Subject<T>
+}