{
  "category": "JavaScript",
  "flag_name": null,
  "id": 5143135809961984,
  "milestone": 140,
  "name": "View Transition finished promise timing change",
  "summary": "The current finished promise timing happens within the rendering lifecycle steps. This means that code that runs as a result of promise resolution happens after the visual frame that removes the view transition has been produced. This can cause a flicker at the end of the animation if script moves some styles around in an attempt to preserve visually similar state (e.g. https://vmpstr.github.io/htmldemos/vt/flicker.html)\r\n\r\nThis change rectifies the situation by moving the ViewTransition clean up steps to run asynchronously after the lifecycle is completed. This ensures that visual frame produced at finished promise resolution still maintains the View Transition structure, allowing developers to avoid the flicker.\r\n\r\nMore info: https://github.com/w3c/csswg-drafts/issues/12442"
}

{
  "category": "JavaScript",
  "flag_name": "--js_base_64",
  "id": 6281131254874112,
  "milestone": 140,
  "name": "Uint8Array to/from base64 and hex",
  "summary": "base64 is a common way to represent arbitrary binary data as ASCII. JavaScript has Uint8Arrays to work with binary data, but no built-in mechanism to encode that data as base64, nor to take base64'd data and produce a corresponding Uint8Arrays. This is a proposal to fix that. It also adds methods for converting between hex strings and Uint8Arrays."
}

{
  "category": "JavaScript",
  "flag_name": null,
  "id": 5067126381215744,
  "milestone": 142,
  "name": "activeViewTransition property on document",
  "summary": "View Transitions API allows developers to start visual transitions between different states. The primary SPA entry point to this is `startViewTransition()` which returns a transition object. This object contains several promises and functionality to track the transition progress, as well as allow manipulations such as skipping the transition or modifying its types.\r\n\r\nThe proposal here is ergonomic in nature: instead of requiring that users store this object in some sort of way for easy access, provide a `document.activeViewTransition` property that represents this object, or null if there is no transition ongoing.\r\n\r\nNote this similarly applies to MPA transitions, where the object is only available via `pageswap` and `pagereveal` events. In this proposal `document.activeViewTransition` would be set to this object for the duration of the transition."
}