misc: rerun tests on unloadEvent instead of on beforeunload

[mabela416]

• Closes
  https://github.com/cypress-io/cypress-services/issues/12584

Additional details

---

Note

Medium Risk
Changes core runner lifecycle behavior for when tests are restarted and cookies/state are cleared, which could alter navigation/teardown timing across browsers.

Overview
Rerun/reset is now tied to real unload events. The runner (event-manager.ts) stops triggering test restarts/state cleanup on beforeunload and instead does so on pagehide for Chromium and unload for other browsers, avoiding reruns when a beforeunload confirmation is cancelled.

Updates the 15.12.0 changelog to document this behavior change under Misc.

^{Written by Cursor Bugbot for commit 14dd14d. This will update automatically on new commits. Configure here.}

Steps to test

• Needs to be tested along with https://github.com/cypress-io/cypress-services/pull/12974

How has the user experience changed?

PR Tasks

• Have tests been added/updated?
• Has a PR for user-facing changes been opened in cypress-documentation?
• Have API changes been updated in the type definitions?

[cypress]

cypress    Run #69299

Run Properties:   Failed #69299  •  14dd14dbf6: fix changelog

Project	cypress
Branch Review	mabel/issue-12584-unsaved-changes-on-refresh
Run status	Failed #69299
Run duration	49m 05s
Commit	14dd14dbf6: fix changelog
Committer	Mabel Amaya
View all properties for this run ↗︎

---

Test results
Failures	268
Flaky	1
Pending	106
Skipped	20
Passing	4304
View all changes introduced in this branch ↗︎

---

Warning

Partial Report: The results for the Application Quality reports may be incomplete.

UI Coverage  30%
Untested elements	33
Tested elements	15

Accessibility  99.32%
Failed rules	0 critical   3 serious   0 moderate   0 minor
Failed elements	13

---

Tests for review

  e2e/origin/cookie_login.cy.ts • 43 failed tests • 5x-driver-electron

View Output

Test		Artifacts
cy.origin - cookie login > general behavior > handles browser-sent cookies being overridden by server-kept cookies		Test Replay
cy.origin - cookie login > general behavior > cy.clearCookie() -> not logged in		Test Replay
cy.origin - cookie login > general behavior > cy.clearCookies() -> not logged in		Test Replay
cy.origin - cookie login > SameSite > no SameSite (defaults to Lax) -> logged in		Test Replay
cy.origin - cookie login > SameSite > SameSite=Lax -> logged in		Test Replay
cy.origin - cookie login > SameSite > SameSite=Strict -> not logged in		Test Replay
cy.origin - cookie login > SameSite > SameSite=None -> not logged in		Test Replay
cy.origin - cookie login > SameSite > invalid SameSite (defaults to Lax) -> logged in		Test Replay
cy.origin - cookie login > Secure > Secure + https -> logged in		Test Replay
cy.origin - cookie login > Secure > Secure + http -> not logged in		Test Replay
The first 10 failed tests are shown, see all 43 tests in Cypress Cloud.

  memory/memory.cy.js • 0 failed tests • 5x-driver-electron

View Output

Test		Artifacts

  commands/actions/click.cy.ts • 0 failed tests • 5x-driver-electron

View Output

Test		Artifacts

  commands/actions/type_special_chars.cy.ts • 0 failed tests • 5x-driver-electron

View Output

Test		Artifacts

  memory/dom-stress-test.cy.js • 0 failed tests • 5x-driver-electron

View Output

Test		Artifacts

The first 5 failed specs are shown, see all 1165 specs in Cypress Cloud.

  cypress/e2e/commands/net_stubbing.cy.ts • 1 flaky test • 5x-driver-firefox

View Output

Test		Artifacts
... > stops waiting when an xhr request is canceled		</td> </tr></table>