Contents

Safari Technology Preview 2 Release Notes

Preview the latest web technology updates including: Browser Differences, JavaScript, CSS, Web APIs, Web Inspector, Accessibility, Rendering, Media, Networking, and bug fixes.

Overview

Safari Technology Preview Release 2 is now available for download. If you already have Safari Technology Preview installed, you can update from the Mac App Store’s Updates tab. Release 2 of Safari Technology Preview covers WebKit revisions 198530–199085.

Browser Differences

  • Changed the CFBundleSignature to allow Apple Events, like those sent from AppleScript, to correctly distinguish between Safari and Safari Technology Preview

JavaScript

  • Added ES6 support for Symbol.isConcatSpreadable (r198808)

  • Disallowed var assignments in for-in loops according to ES6 specs (r198928)

  • Improved stability for ES6 classes when invoking a method of the parent class before calling super() in a constructor (r198714)

  • Allowed undefined or null for Symbol.search and Symbol.match (r198581)

  • Enabled Array.prototype native functions’ species constructors to work with proxies (r198589)

  • Implemented the proposal for String.prototype.padStart() and String.prototype.padEnd() (r198674)

  • Implemented ES6 spec for String.prototype.match and RegExp.prototype[@@match] (r198554)

  • Included a workaround for web compatibility on ES6 TypeErrors when accessing RegExp.prototype flag properties (r198698)

  • Corrected quantified unicode regular expressions (r198866)

  • Ensured greedy unicode regular expressions properly backtrack past non-BMP characters (r198624)

CSS

  • Implemented the allow-end value of the hanging-punctuation CSS property (r198683)

  • Improved web compatibility by resetting CSS spacing rules on <math> elements (r198952)

  • Added the new color-gamut CSS media query (r199024)

  • Updated screen queries to check the capabilities of the current screen instead of the deepest available screen (r198595)

Web APIs

  • Restricted WebSockets header parsing according to RFC6455 and RFC7230 (r198561)

  • Improved performance of certain draw calls in WebGL with a non-power-of-two texture optimization (r198588)

  • Disabled the Fetch API until the implementation is ready to be enabled by default (r199081)

  • Enhanced Shadow DOM support to compute styles for the style attribute of <slot> elements (r198990)

  • Softened pushState and replaceState frequency restrictions (r198687)

Web Inspector

  • Timelines tab performance and bug fixes (r198550, r198563, r198601, r198602, r198603, r198618, r198620, r198745, r199077, r199085)

  • Disabled debugger statements and breakpoints while profiling a page to ensure maximum performance accuracy (r198648)

  • Added the ability to configure timeline instruments to use for recordings (r198537)

  • Added a paint count indicator in the top left corner of non-opaque layers (r198599)

  • Added font-variant-numeric to CSS autocompletions (r198750)

  • Added the console.takeHeapSnapshot method for capturing heap snapshots (r198786)

  • Changed details sidebar shortcuts to Command-Option-0 and Command-Shift-0 (r199082)

  • Double-quotes and backslashes in strings are now displayed correctly in the console (r198585)

  • Improved the consistency of CSP directive violation messages reported in the console (r198591)

Accessibility

  • Corrected new lines in content editable elements to notify accessibility (r199030)

  • Updated the handling of SVG elements with a presentational role to be the same as other host language elements (r198870)

  • Limited the numbered list announcement for a list item number to the first line of text in the list item (r198806)

  • Changed the accessibility role descriptions for JavaScript alerts to “web dialog” and “web alert dialog” to make them more understandable to screen reader users (r198543)

Rendering

  • Updated backdrop filter to repaint when changed in JavaScript (r198963)

  • Corrected drawing SVG stroke patterns for objects with empty bounding box elements (r198574)

Media

  • Improved stability when an audio source is changed while being processed (r198654)

  • Fixed audio track listings (r198703)

Networking

  • Improved the reliability of speculative disk cache validation requests with the HTTP Referer header (r198741)

Bug Fixes

  • Fixed autoscrolling in a drag selection when a window is against the screen edge, including while in full screen mode (r198692)

See Also

2016