fall back to Worker if SharedWorker not supported

Author: aaronshaf

packages/idb-cache/src/encryptionTasks.ts

@@ -17,7 +17,7 @@ import {
  * @throws {EncryptionError} If encryption fails.
  */
 export async function encryptChunk(
-  port: MessagePort,
+  port: MessagePort | Worker,
   value: string,
   pendingRequests: Map<string, ExtendedPendingRequest<EncryptedChunk>>
 ): Promise<EncryptedChunk> {
@@ -60,7 +60,7 @@ export async function encryptChunk(
  * @throws {DecryptionError} If decryption fails.
  */
 export async function decryptChunk(
-  port: MessagePort,
+  port: MessagePort | Worker,
   iv: ArrayBuffer,
   ciphertext: ArrayBuffer,
   pendingRequests: Map<string, ExtendedPendingRequest<string>>

packages/idb-cache/src/index.ts

@@ -103,8 +103,8 @@ const isSubtleCryptoSupported = crypto?.subtle;
 export class IDBCache implements IDBCacheInterface {
   dbReadyPromise: Promise<import("idb").IDBPDatabase<IDBCacheSchema>>;
   private storeName: STORE;
-  private worker: SharedWorker | null = null;
-  private port: MessagePort | null = null;
+  private worker: SharedWorker | Worker | null = null;
+  private port: MessagePort | Worker | null = null;
   private pendingRequests: Map<
     string,
     ExtendedPendingRequest<EncryptedChunk | string>
@@ -397,7 +397,7 @@ export class IDBCache implements IDBCacheInterface {
     await this.workerReadyPromise;
   }
 
-  private getPort(): MessagePort {
+  private getPort(): MessagePort | Worker {
     if (!this.port) {
       throw new WorkerInitializationError("Worker port is not initialized.");
     }
@@ -826,7 +826,11 @@ export class IDBCache implements IDBCacheInterface {
       }
 
       if (this.worker) {
-        this.worker.port.close();
+        if (this.worker instanceof SharedWorker) {
+          this.worker.port.close();
+        } else {
+          this.worker.terminate();
+        }
         this.worker = null;
       }
 

packages/idb-cache/src/workerUtils.ts

@@ -63,32 +63,48 @@ export function createWorkerFromFunction(
   fn: () => void,
   rejectAll: (errorMessage: string) => void
 ): {
-  worker: SharedWorker;
-  port: MessagePort;
+  worker: SharedWorker | Worker;
+  port: MessagePort | Worker;
 } {
   const scriptSource = `(${fn.toString()})()`;
   const base64Source = btoa(scriptSource);
   const url = `data:application/javascript;base64,${base64Source}`;
-  const worker = new SharedWorker(url, {
+  const options = {
     name: "idb-cache-worker",
-  });
+  };
 
-  const port = worker.port;
+  let worker: SharedWorker | Worker;
+  let port: MessagePort | Worker;
 
-  port.start();
+  if ("SharedWorker" in window) {
+    worker = new SharedWorker(url, options);
+    port = worker.port;
+    port.start();
+  } else {
+    worker = new Worker(url, options);
+    port = worker;
+  }
 
   worker.onerror = (event) => {
     console.error("SharedWorker encountered an error:", event.message);
     rejectAll("SharedWorker encountered an error and was terminated.");
-    worker.port.close();
+    if (worker instanceof SharedWorker) {
+      worker.port.close();
+    } else {
+      worker.terminate();
+    }
   };
 
   port.onmessageerror = () => {
     console.warn(
       "MessagePort encountered a message error. SharedWorker may have been terminated."
     );
     rejectAll("SharedWorker was terminated unexpectedly.");
-    port.close();
+    if (port instanceof MessagePort) {
+      port.close();
+    } else {
+      port.terminate();
+    }
   };
 
   return { worker, port };
@@ -118,7 +134,7 @@ export function rejectAllPendingRequests(
  * @param pendingRequests - Map of pending requests awaiting responses.
  */
 export function initializeWorker(
-  port: MessagePort,
+  port: MessagePort | Worker,
   resolveReady: () => void,
   rejectReady: (reason?: unknown) => void,
   pendingRequests: Map<string, ExtendedPendingRequest<EncryptedChunk | string>>
@@ -185,7 +201,11 @@ export function initializeWorker(
       pendingRequests,
       "SharedWorker encountered an error and was terminated."
     );
-    port.close();
+    if (port instanceof MessagePort) {
+      port.close();
+    } else {
+      port.terminate();
+    }
   };
 }
 
@@ -200,7 +220,7 @@ export function initializeWorker(
  * @returns A promise that resolves with the worker's response.
  */
 export async function sendMessageToWorker<T extends WorkerMessage["type"]>(
-  port: MessagePort,
+  port: MessagePort | Worker,
   requestId: string,
   message: Extract<WorkerMessage, { type: T }>,
   pendingRequests: Map<string, ExtendedPendingRequest<WorkerResponseType<T>>>,