Apple Developer:「Safari Technology Preview Release 27」配布

Safari Technology PreviewApple

Apple は、開発者向けに「Safari Technology Preview Release 27」を配布しています。







Apple Developer ダウンロードページもしくはMac App Storeよりアップデート可能です。


Release 27

Browser Changes

  • Added a “Reload Page From Origin” alternate menu item to the View menu. This action reloads a page without using cached resources.
  • Removed the Option-Command-R (⌥⌘R) keyboard shortcut from “Enter/Exit Responsive Design Mode” and mapped it to “Reload Page From Origin” instead.
  • Removed the Disable Caches menu item in the Develop menu. The equivalent functionality is now available through Web Inspector’s Network tab.


  • Implemented ESNext Object Spread proposal
  • Changed to allow labels named let when parsing a statement in non-strict mode
  • Fixed const location = "foo" in a worker to not throw a SyntaxError


  • Aligned initEvent, initCustomEvent, initMessageEvent with the latest specification
  • Aligned Document.elementFromPoint() with the CSSOM specification
  • Changed XMLHttpRequest getAllResponseHeaders() to transform header names to lowercase before sorting
  • Fixed sending an empty "Access-Control-Request-Headers" in preflight requests
  • Implemented self.origin
  • Implemented the “noopener” feature for
  • Improved index validation when using uint index values in WebGL
  • Prevented beforeunload alerts when the user hasn’t interacted with the web page
  • Prevented innerText setter from inserting an empty text node if the value starts with a newline
  • Prevented new navigations during document unload
  • Prevented WebSQL databases from being openable in private browsing
  • Changed serialization of custom properties in longhand to be "", not the value of the shorthand property
  • Changed to tear down descendant renderers when a <slot> display value is set to "contents"


  • Fixed pausing animated SVG images when they are outside the viewport, or removed from the document
  • Changed asynchronous image decoding to consider when the drawing size is smaller than the size of the image
  • Prevented large images from being decoded asynchronously when they are drawn on a canvas
  • Fixed the flow state for positioned inline descendants
  • Fixed initial letter rendering that follows pagination
  • Fixed clipping columns horizontally in multi-column layout
  • Fixed animated GIFs that fail to play in multi-column layout


  • Fixed an issue where a dynamically applied :empty pseudo class with display:none does not get unapplied
  • Unprefixed -webkit-min-content, -webkit-max-content and -webkit-fit-content


  • Fixed loading media files in a <video> tag that are served without a filename extension
  • Suspended silent videos playback in background tabs to save CPU

Web Inspector

  • Added “Disable Caches” toggle in the Networking tab that only applies to the inspected page while Web Inspector is open.
  • Added “Save Selected” context menu item to Console
  • Added RTL support to the Timeline tab
  • Added RTL support for the Find banner
  • Added more accurate Resource Timing data in Web Inspector
  • Added context menu item to log content of WebSocket frame
  • Added icons for SVG Image cluster path components
  • Added keyboard shortcut to clear timeline records
  • Added a connection indicator for when a WebSocket connection is open or close
  • Changed Option-clicking the close tab button to close all other tabs
  • Changed to allow the user to copy locked CSS selectors in Style Rules sidebar
  • Changed to allow users to click links in inline and user-agent styles
  • Changed SVG image content view to allow toggling between the image and source
  • Changed Event Listeners detail section to show listeners by element rather than by event
  • Changed Event Listeners to add missing ‘once’ and ‘passive’ event listener flags
  • Fixed an issue where adding a WebSocket message could change the currently selected resource
  • Fixed clicking DOM breakpoint marker to enable and disable breakpoints
  • Fixed an exception when clicking on Clear Network Items icon with the timing popover visible
  • Fixed local storage keys and values starting with truncated strings
  • Fixed empty attributes added to a DOM tree outline element adding whitespace within the tag
  • Fixed an exception when fetching computed styles that can break future updates of section
  • Fixed syntax highlighting and formatting when inspecting a main resource that is JavaScript or JSON
  • Fixed pseudo-class markers overlapping DOM breakpoints and disclosure triangles
  • Fixed an issue causing the Resource details sidebar to display previous image metrics when viewing resource where content load failed
  • Fixed text selection in the Console to select only message text
  • Fixed formatting JSON request data
  • Fixed the filename used when saving a resource from the resource image content view
  • The file save dialog no longer suggests the top level directory as the default location


  • Fixed VoiceOver for editable text on the web


  • Added support for SPKI/PKCS8 Elliptic Curve cryptography