Apple Releases Safari Technology Preview 33 for macOS Sierra and High Sierra [Download]

Apple has released Safari Technology Preview 33 for macOS Sierra and macOS High Sierra. Safari Technology Preview offers a sneak peek at upcoming web technologies in macOS and iOS.

Here are the release notes:

Performance
● Fixed an issue that could lead to large memory use in the Safari Technology Preview and web content processes when certain Safari Extensions are installed


JavaScript
● Fixed for-in optimization static analysis in the bytecode generator
● Improved performance of String.prototype.concat
● Improved the bytecode and type information provided for toLength
● Optimized Map and Set constructors

WebRTC
● Added WebRTC stats logging

Media Streams and Capture
● Fixed getUserMedia prompting too often
● Prevented getUserMedia requests from background tabs unless the tab is already capturing
● Prevented getUserMedia from prompting again if the user denied access

Media
● Enabled clients to specify a list of codecs that should require hardware decode support
● Exempted exclusively wall-powered devices from client-required hardware codec support
● Aligned Web Audio implementation to specifications when clients pass a value of 0 for bufferSize to the createScriptProcessor() method


CSS Grid
● Added support for orthogonally positioned grid items
● Fixed the behavior of positioned items without specific dimensions
● Fixed the logical margin applied in the tracks sizing algorithm of auto tracks
● Fixed margin applied when stretching an orthogonal item in a fixed size track

Web API
● Aligned and limits with the latest HTML specification
● Fixed null content-type and content-length when fetching Blob URLs with XHR
● Fixed getComputedStyle() to return pixel values for left, right, top, and bottom, matching the specifications
● Implemented fromFloat32Array, fromFloat64Array, toFloat32Array, and toFloat64Array for DOMMatrix
● Implemented DOMPointReadOnly.matrixTransform()
● Enabled script modules to be imported via data URLs
● Updated to slightly stricter rules for custom element names from the recent draft standards
● Used the parent box style to adjust RenderStyle for alignment
● Added conditional support for media preloading and aligned media as values
● Aligned preload implementation to specifications with mandatory as value and other alignments

Rendering
● Changed behavior to remove backing store for layers that are outside the viewport
● Fixed an issue where a frame’s composited content is visible when the frame has visibility:hidden
● Changed behavior to destroy the associated renderer subtree when display:contents node is deleted

Web Inspector
● Added contextual menu item to log a WebSocket object to the console
● Added Debug view to the Settings tab for debug settings and experimental features
● Added the ability for the user to choose stylesheet when creating new rules
● Changed the Node Details Sidebar to allow editable key and values in the Attributes table
● Prevented unnecessary layout triggered when a Sidebar is resized while collapsed
● Fixed performing search on reload for an existing query in the Search tab
● Fixed images dragged from Web Inspector to Desktop being named “Unknown.png”
● Fixed an issue where reloading the page after switching from the Resource tab switches back
● Fixed the CodeMirror instance in the ConsolePrompt getting refreshed each time it is shown
● Fixed showing active Web Sockets when opening Web Inspector
● Fixed an issue preventing the go-to arrow to inspect Web Sockets that receive >50 messages per second
● Improved the reliability of automatically pausing in auto-attach when inspecting a JSContext

Bug Fixes
● Enabled AirPods to work with Netflix
● Fixed stuttering audio in YouTube when the page changes visibility