fix(router): avoid view transitions when the user agent provides one - #70140
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fix(router): avoid view transitions when the user agent provides one#70140SkyZeroZx wants to merge 2 commits into
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atscott
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reviewed-for: public-api
Preserve hasUAVisualTransition through Location and the Router navigation pipeline. This prevents withViewTransitions from starting an author transition after the browser has already performed one, including across redirects and when using experimental platform navigation. References: https://html.spec.whatwg.org/multipage/nav-history-apis.html#dom-popstateevent-hasuavisualtransition https://html.spec.whatwg.org/multipage/nav-history-apis.html#dom-navigateevent-hasuavisualtransition https://developer.chrome.com/docs/web-platform/view-transitions/same-document#integration-with-the-navigation-api-and-other-frameworks
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| jasmine.objectContaining({ | ||
| canIntercept: true, | ||
| hashChange: false, | ||
| hasUAVisualTransition: false, |
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I suspect this is showing how this is going to be breaking for tests
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| const hasUAVisualTransition = event.hasUAVisualTransition === true; | ||
| const invokeListener = () => { | ||
| listener( | ||
| event['url']!, | ||
| event.state as RestoredState | null | undefined, | ||
| 'popstate', | ||
| { | ||
| replaceUrl: true, | ||
| }, | ||
| hasUAVisualTransition, | ||
| ); | ||
| }; | ||
|
|
||
| if (hasUAVisualTransition) { | ||
| // A UA visual transition has already started. Schedule the navigation immediately so | ||
| // the browser can present the post-navigation DOM without an additional task. | ||
| invokeListener(); | ||
| return; | ||
| } |
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We shouldn't bypass setTimeout here for hasUAVisualTransition.
- Guards & Resolvers: Router navigations frequently involve asynchronous guards, resolvers, lazy loading, or data fetching, so there is no guarantee that the DOM update can be completed in the current task anyway.
- Timing Consistency: Deferring popstate navigations with
setTimeoutis an established router behavior. Introducing a timing fork where swipe-back gestures execute synchronously but back-button clicks execute in a macrotask adds unnecessary timing discrepancies into the router state machine.
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requesting changes for revert of synchronous listener invocation
atscott
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Aug 14, 2026
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Preserve hasUAVisualTransition through Location and the Router navigation pipeline. This prevents withViewTransitions from starting an author transition after the browser has already performed one, including across redirects and when using experimental platform navigation.
References:
https://html.spec.whatwg.org/multipage/nav-history-apis.html#dom-popstateevent-hasuavisualtransition
https://html.spec.whatwg.org/multipage/nav-history-apis.html#dom-navigateevent-hasuavisualtransition
https://developer.chrome.com/docs/web-platform/view-transitions/same-document#integration_with_the_navigation_api_and_other_frameworks
Note:
Although the article mentions that swipe gestures are not a default behavior, this is not currently true in Chrome 150 on Android; the feature flag does not exist and it has become the default behavior.
What is the current behavior?
without_skip_router-ua-view-transition.mp4
What is the new behavior?
fixed_router-ua-view-transition.mp4