fixup! fix(clerk-js): Prevent session cookie removal during offline token refresh

Author: bratsos

packages/clerk-js/bundlewatch.config.json

@@ -1,6 +1,6 @@
 {
   "files": [
-    { "path": "./dist/clerk.js", "maxSize": "539KB" },
+    { "path": "./dist/clerk.js", "maxSize": "540KB" },
     { "path": "./dist/clerk.browser.js", "maxSize": "66KB" },
     { "path": "./dist/clerk.legacy.browser.js", "maxSize": "108KB" },
     { "path": "./dist/clerk.no-rhc.js", "maxSize": "307KB" },

packages/shared/src/__tests__/browser.spec.ts

@@ -162,15 +162,15 @@ describe('isValidBrowserOnline', () => {
     expect(isValidBrowserOnline()).toBe(false);
   });
 
-  it('returns FALSE if connection is NOT online, navigator is online, has disabled the webdriver flag, and is not a bot', () => {
+  it('returns TRUE if connection reports zero values but navigator is online (headless browser)', () => {
     userAgentGetter.mockReturnValue(
       'Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:109.0) Gecko/20100101 Firefox/109.0',
     );
     webdriverGetter.mockReturnValue(false);
     onLineGetter.mockReturnValue(true);
     connectionGetter.mockReturnValue({ downlink: 0, rtt: 0 });
 
-    expect(isValidBrowserOnline()).toBe(false);
+    expect(isValidBrowserOnline()).toBe(true);
   });
 
   it('returns FALSE if connection is online, navigator is NOT online, has disabled the webdriver flag, and is not a bot', () => {

packages/shared/src/browser.ts

@@ -73,13 +73,12 @@ export function isBrowserOnline(): boolean {
     return false;
   }
 
-  const isNavigatorOnline = navigator?.onLine;
-
-  // Being extra safe with the experimental `connection` property, as it is not defined in all browsers
-  // https://developer.mozilla.org/en-US/docs/Web/API/Navigator/connection#browser_compatibility
-  // @ts-ignore
-  const isExperimentalConnectionOnline = navigator?.connection?.rtt !== 0 && navigator?.connection?.downlink !== 0;
-  return isExperimentalConnectionOnline && isNavigatorOnline;
+  // navigator.onLine is the standard API and is reliable for detecting
+  // complete disconnection (airplane mode, WiFi off, etc.).
+  // The experimental navigator.connection API (rtt/downlink) was previously
+  // used as a secondary signal, but it reports zero values in headless browsers
+  // and CI environments even when connected, causing false offline detection.
+  return !!navigator.onLine;
 }
 
 /**