feat: remove page hide event from triggering unload event listener

cli/CHANGELOG.md

@@ -14,6 +14,7 @@ _Released 07/01/2025 (PENDING)_
 - `@cypress/webpack-dev-server` and `@cypress/webpack-preprocessor` no longer support `webpack` version 4. Addresses [#31344](https://github.com/cypress-io/cypress/issues/31344). If you still need to use `webpack` version 4, please see our [migration guide](https://docs.cypress.io/app/references/migration-guide#Migrating-to-Cypress-150).
 - `@cypress/webpack-dev-server` no longer supports `webpack-dev-server` version 4. Addresses [#31605](https://github.com/cypress-io/cypress/issues/31605). If you still need to use `webpack-dev-server` version 4, please see our [migration guide](https://docs.cypress.io/app/references/migration-guide#Migrating-to-Cypress-150).
 - The `@cypress/webpack-batteries-included-preprocessor` no longer includes browser built-ins that were automatically provided by Webpack 4. To add built-ins manually, refer to the Webpack [resolve.fallback](https://webpack.js.org/configuration/resolve/#resolvefallback) documentation and the [`@cypress/webpack-batteries-included-preprocessor` README](../npm/webpack-batteries-included-preprocessor/README.md). Addresses [#31039](https://github.com/cypress-io/cypress/issues/31039).
+- The application under test's `pagehide` event in Chromium browsers will no longer trigger Cypress's `window:unload` event. Addressed in [#31853](https://github.com/cypress-io/cypress/pull/31853).
 
 **Features:**
 

packages/driver/cypress/e2e/commands/navigation.cy.js

@@ -97,15 +97,13 @@ describe('src/cy/commands/navigation', () => {
     })
 
     it('removes listeners', () => {
-      cy.log(Cypress.browser)
-      const unloadEvent = Cypress.browser.family === 'chromium' ? 'pagehide' : 'unload'
       const win = cy.state('window')
 
       const rel = cy.stub(win, 'removeEventListener')
 
       cy.reload().then(() => {
         expect(rel).to.be.calledWith('beforeunload')
-        expect(rel).to.be.calledWith(unloadEvent)
+        expect(rel).to.be.calledWith('unload')
       })
     })
 
@@ -415,10 +413,8 @@ describe('src/cy/commands/navigation', () => {
         const rel = cy.stub(win, 'removeEventListener')
 
         cy.go('back').then(() => {
-          const unloadEvent = cy.browser.family === 'chromium' ? 'pagehide' : 'unload'
-
           expect(rel).to.be.calledWith('beforeunload')
-          expect(rel).to.be.calledWith(unloadEvent)
+          expect(rel).to.be.calledWith('unload')
         })
       })
     })

packages/driver/src/cross-origin/cypress.ts

@@ -220,13 +220,10 @@ const attachToWindow = (autWindow: Window) => {
       Cypress.specBridgeCommunicator.toPrimary('window:load', { url: remoteLocation.href })
       cy.isStable(true, 'load')
     },
-    onPageHide (e) {
+    onUnload (e) {
       cy.state('window', undefined)
       cy.state('document', undefined)
 
-      // unload is being actively deprecated/removed by chrome, so for
-      // compatibility, we are using `window`'s `pagehide` event as a proxy
-      // for the `window:unload` event that we emit. See: https://github.com/cypress-io/cypress/pull/29525
       return Cypress.action('app:window:unload', e)
     },
     onNavigation (...args) {

packages/driver/src/cy/listeners.ts

@@ -61,7 +61,7 @@ type BoundCallbacks = {
   onSubmit: (e) => any
   onLoad: (e) => any
   onBeforeUnload: (e) => undefined | Promise<undefined>
-  onPageHide: (e: PageTransitionEvent) => any
+  onUnload: (e: BeforeUnloadEvent) => any
   onNavigation: (...args) => any
   onAlert: (str) => any
   onConfirm: (str) => boolean
@@ -93,18 +93,12 @@ export const bindToListeners = (contentWindow, callbacks: BoundCallbacks) => {
     await callbacks.onBeforeUnload(e)
   })
 
-  // While we must move to pagehide for Chromium, it does not work for our
-  // needs in Firefox. Until that is addressed, only Chromium uses the pagehide
-  // event as a proxy for AUT unloads.
-
-  const unloadEvent = Cypress.browser.family === 'chromium' ? 'pagehide' : 'unload'
-
-  addListener(contentWindow, unloadEvent, (e) => {
+  addListener(contentWindow, 'unload', (e) => {
     // when we unload we need to remove all of the event listeners
     removeAllListeners()
 
     // else we know to proceed onwards!
-    callbacks.onPageHide(e)
+    callbacks.onUnload(e)
   })
 
   addListener(contentWindow, 'hashchange', (e) => {

packages/driver/src/cypress/cy.ts

@@ -1130,10 +1130,7 @@ export class $Cy extends EventEmitter2 implements ITimeouts, IStability, IAssert
         // doesn't trigger a confirmation dialog
         return undefined
       },
-      onPageHide (e) {
-        // unload is being actively deprecated/removed by chrome, so for
-        // compatibility, we are using `window`'s `pagehide` event as a proxy
-        // for the `window:unload` event that we emit. See: https://github.com/cypress-io/cypress/pull/29525
+      onUnload (e) {
         return cy.Cypress.action('app:window:unload', e)
       },
       onNavigation (...args) {