fix/webtransportation-getOriginalFetch

.pubnub.yml

@@ -1,5 +1,10 @@
 ---
 changelog:
+  - date: 2026-07-22
+    version: v12.0.2
+    changes:
+      - type: bug
+        text: "Fixes issue of getting error while obtain APM safe fetch api."
   - date: 2026-07-21
     version: v12.0.1
     changes:
@@ -1432,7 +1437,7 @@ supported-platforms:
       - 'Ubuntu 14.04 and up'
       - 'Windows 7 and up'
     version: 'Pubnub Javascript for Node'
-version: '12.0.1'
+version: '12.0.2'
 sdks:
   - full-name: PubNub Javascript SDK
     short-name: Javascript
@@ -1448,7 +1453,7 @@ sdks:
           - distribution-type: source
             distribution-repository: GitHub release
             package-name: pubnub.js
-            location: https://github.com/pubnub/javascript/archive/refs/tags/v12.0.1.zip
+            location: https://github.com/pubnub/javascript/archive/refs/tags/v12.0.2.zip
             requires:
               - name: 'agentkeepalive'
                 min-version: '3.5.2'
@@ -2119,7 +2124,7 @@ sdks:
           - distribution-type: library
             distribution-repository: GitHub release
             package-name: pubnub.js
-            location: https://github.com/pubnub/javascript/releases/download/v12.0.1/pubnub.12.0.1.js
+            location: https://github.com/pubnub/javascript/releases/download/v12.0.2/pubnub.12.0.2.js
             requires:
               - name: 'agentkeepalive'
                 min-version: '3.5.2'

CHANGELOG.md

@@ -1,3 +1,9 @@
+## v12.0.2
+July 22 2026
+
+#### Fixed
+- Fixes issue of getting error while obtain APM safe fetch api.
+
 ## v12.0.1
 July 21 2026
 

README.md

@@ -27,8 +27,8 @@ Watch [Getting Started with PubNub JS SDK](https://app.dashcam.io/replay/64ee0d2
      npm install pubnub
      ```
    * or download one of our builds from our CDN: 
-     * https://cdn.pubnub.com/sdk/javascript/pubnub.12.0.1.js
-     * https://cdn.pubnub.com/sdk/javascript/pubnub.12.0.1.min.js
+     * https://cdn.pubnub.com/sdk/javascript/pubnub.12.0.2.js
+     * https://cdn.pubnub.com/sdk/javascript/pubnub.12.0.2.min.js
 
    > **React Native:** the SDK relies on a global `URL` implementation, which React Native does not
    > provide, so it depends on [`react-native-url-polyfill`](https://www.npmjs.com/package/react-native-url-polyfill).

dist/web/pubnub.js

@@ -5477,7 +5477,7 @@
 	            return base.PubNubFile;
 	        },
 	        get version() {
-	            return '12.0.1';
+	            return '12.0.2';
 	        },
 	        getVersion() {
 	            return this.version;
@@ -5948,13 +5948,22 @@
 	        this.logger = logger;
 	        this.transport = transport;
 	        logger.debug('WebTransport', `Create with configuration:\n  - transport: ${transport}`);
-	        if (transport === 'fetch' && (!window || !window.fetch)) {
+	        // Check for `fetch` availability directly (works in DOM and DOM-less contexts such as service workers).
+	        // because a bare `window` reference would throw in a service worker, and a partial `window = self` shim can
+	        // define `window` without `fetch`, so probe the actual `fetch` global via `typeof`.
+	        if (transport === 'fetch' && typeof fetch === 'undefined') {
 	            logger.warn('WebTransport', `'${transport}' not supported in this browser. Fallback to the 'xhr' transport.`);
 	            this.transport = 'xhr';
 	        }
 	        if (this.transport !== 'fetch')
 	            return;
 	        // Storing reference on original `fetch` function implementation as protection against APM lib monkey patching.
+	        //
+	        // This is done unconditionally (not gated on `isFetchMonkeyPatched()`): APM libraries can defeat that
+	        // detection by overriding stringification to report `[native code]` while still patching `fetch`, so we
+	        // cannot rely on it to decide whether the workaround is needed. `getOriginalFetch()` itself decides how to
+	        // obtain the reference based on the environment (iframe when a DOM is available, context `fetch` otherwise),
+	        // which keeps construction safe in DOM-less contexts such as MV3 service workers.
 	        WebTransport.originalFetch = WebTransport.getOriginalFetch();
 	        // Check whether `fetch` has been monkey patched or not.
 	        if (this.isFetchMonkeyPatched())
@@ -6259,6 +6268,12 @@
 	     * @returns Reference to the `fetch` function.
 	     */
 	    static getOriginalFetch() {
+	        // The iframe-based APM workaround requires a DOM. In DOM-less contexts (e.g. MV3 service workers) there is
+	        // no `document`, and `fetch` cannot be reached through a fresh browsing context — return the context `fetch`
+	        // directly. This is safe there: without a DOM there is no APM page script to monkey patch `fetch` in the
+	        // first place. This environment check is what keeps the unconditional call in the constructor safe.
+	        if (typeof document === 'undefined' || !document.body)
+	            return fetch;
 	        let iframe = document.querySelector('iframe[name="pubnub-context-unpatched-fetch"]');
 	        if (!iframe) {
 	            iframe = document.createElement('iframe');
@@ -18462,7 +18477,9 @@
 	                    authenticationChangeHandler = (auth) => middleware.onTokenChange(auth);
 	                    userIdChangeHandler = (userId) => middleware.onUserIdChange(userId);
 	                    transport = middleware;
-	                    if (configurationCopy.subscriptionWorkerUnsubscribeOfflineClients) {
+	                    if (configurationCopy.subscriptionWorkerUnsubscribeOfflineClients &&
+	                        typeof window !== 'undefined' &&
+	                        window.addEventListener) {
 	                        window.addEventListener('pagehide', (event) => {
 	                            if (!event.persisted)
 	                                middleware.terminate();
@@ -18512,7 +18529,11 @@
 	                };
 	            }
 	        }
-	        if ((_a = configuration.listenToBrowserNetworkEvents) !== null && _a !== void 0 ? _a : true) {
+	        // `window` is unavailable in DOM-less contexts (e.g. MV3 service workers); only attach network
+	        // listeners when a `window` with event support actually exists.
+	        if (((_a = configuration.listenToBrowserNetworkEvents) !== null && _a !== void 0 ? _a : true) &&
+	            typeof window !== 'undefined' &&
+	            window.addEventListener) {
 	            window.addEventListener('offline', () => {
 	                this.networkDownDetected();
 	            });

lib/core/components/configuration.js

@@ -174,7 +174,7 @@ const makeConfiguration = (base, setupCryptoModule) => {
             return base.PubNubFile;
         },
         get version() {
-            return '12.0.1';
+            return '12.0.2';
         },
         getVersion() {
             return this.version;

package.json

@@ -1,6 +1,6 @@
 {
   "name": "pubnub",
-  "version": "12.0.1",
+  "version": "12.0.2",
   "author": "PubNub <support@pubnub.com>",
   "description": "Publish & Subscribe Real-time Messaging with PubNub",
   "scripts": {

src/core/components/configuration.ts

@@ -245,7 +245,7 @@ export const makeConfiguration = (
       return base.PubNubFile;
     },
     get version(): string {
-      return '12.0.1';
+      return '12.0.2';
     },
     getVersion(): string {
       return this.version;

src/transport/web-transport.ts

@@ -97,7 +97,10 @@ export class WebTransport implements Transport {
   ) {
     logger.debug('WebTransport', `Create with configuration:\n  - transport: ${transport}`);
 
-    if (transport === 'fetch' && (!window || !window.fetch)) {
+    // Check for `fetch` availability directly (works in DOM and DOM-less contexts such as service workers).
+    // because a bare `window` reference would throw in a service worker, and a partial `window = self` shim can
+    // define `window` without `fetch`, so probe the actual `fetch` global via `typeof`.
+    if (transport === 'fetch' && typeof fetch === 'undefined') {
       logger.warn('WebTransport', `'${transport}' not supported in this browser. Fallback to the 'xhr' transport.`);
 
       this.transport = 'xhr';
@@ -106,6 +109,12 @@ export class WebTransport implements Transport {
     if (this.transport !== 'fetch') return;
 
     // Storing reference on original `fetch` function implementation as protection against APM lib monkey patching.
+    //
+    // This is done unconditionally (not gated on `isFetchMonkeyPatched()`): APM libraries can defeat that
+    // detection by overriding stringification to report `[native code]` while still patching `fetch`, so we
+    // cannot rely on it to decide whether the workaround is needed. `getOriginalFetch()` itself decides how to
+    // obtain the reference based on the environment (iframe when a DOM is available, context `fetch` otherwise),
+    // which keeps construction safe in DOM-less contexts such as MV3 service workers.
     WebTransport.originalFetch = WebTransport.getOriginalFetch();
 
     // Check whether `fetch` has been monkey patched or not.
@@ -431,6 +440,12 @@ export class WebTransport implements Transport {
    * @returns Reference to the `fetch` function.
    */
   private static getOriginalFetch(): typeof fetch {
+    // The iframe-based APM workaround requires a DOM. In DOM-less contexts (e.g. MV3 service workers) there is
+    // no `document`, and `fetch` cannot be reached through a fresh browsing context — return the context `fetch`
+    // directly. This is safe there: without a DOM there is no APM page script to monkey patch `fetch` in the
+    // first place. This environment check is what keeps the unconditional call in the constructor safe.
+    if (typeof document === 'undefined' || !document.body) return fetch;
+
     let iframe = document.querySelector<HTMLIFrameElement>('iframe[name="pubnub-context-unpatched-fetch"]');
 
     if (!iframe) {

src/web/index.ts

@@ -158,7 +158,11 @@ export default class PubNub extends PubNubCore<ArrayBuffer | string, PubNubFileP
           userIdChangeHandler = (userId: string) => middleware.onUserIdChange(userId);
           transport = middleware;
 
-          if (configurationCopy.subscriptionWorkerUnsubscribeOfflineClients) {
+          if (
+            configurationCopy.subscriptionWorkerUnsubscribeOfflineClients &&
+            typeof window !== 'undefined' &&
+            window.addEventListener
+          ) {
             window.addEventListener(
               'pagehide',
               (event) => {
@@ -211,7 +215,13 @@ export default class PubNub extends PubNubCore<ArrayBuffer | string, PubNubFileP
       }
     }
 
-    if (configuration.listenToBrowserNetworkEvents ?? true) {
+    // `window` is unavailable in DOM-less contexts (e.g. MV3 service workers); only attach network
+    // listeners when a `window` with event support actually exists.
+    if (
+      (configuration.listenToBrowserNetworkEvents ?? true) &&
+      typeof window !== 'undefined' &&
+      window.addEventListener
+    ) {
       window.addEventListener('offline', () => {
         this.networkDownDetected();
       });