Apple has released Safari Technology Preview Release 89 for macOS Mojave and macOS Catalina beta

New in Release 89:

JavaScript
Implemented nullish coalescing with the ?? operator for ESNext (r247819)

Web API
Added referrerpolicy attribute support for elements (r247509)
Changed window.openDatabase to be overridable (r247434)
Fixed an IndexedDB error where the starting version change transaction may be neglected (r247649)
Fixed the ability to unbold selected text when the system font is used (r247439)
Made storing cross-origin top-level prefetches in HTTP cache optional (r247860)
Moving right by word boundary right before an object element followed by a
element hangs (r247881)
Removed support for beforeload on link=prefetch (r247481)
Compatibility
Fixed Daring Fireball long press highlights that were unnecessarily inflated due to false illegibility (r247792)
Fixed contextual menu actions for YouTube videos (r247901)
Accessibility
Exposed the aria-label attribute for elements (r247891)

Media
Enabled a WebRTC debug mode without encryption (r247438)
Fixed support for FLAC-in-MP4 (r247934)

Web Inspector
Added support for console.screenshot with detached (not in main DOM tree) and elements (r247814)
Added support for console.screenshot with ImageData and ImageBitmap (r247812)
Added a “Show Grid” navigation item for the Images collection in the Resources tab (r248004)
Added an indicator/separator around items in the Images collection in the Resources tab (r248019)
Add special case for about:blank resources to show “Resource has no content” message (r247747)
Fixed display of application/xml content for XHR requests (r247533)
Fixed issues toggling multiple breakpoints when they’re collapsed into one line (r247639)
Fixed Command-X (⌘X) to cut selected properties in the Styles sidebar (r247760)
Made the Changes panel in the Elements Tab render with LTR text direction (r247492)

WebGPU
Implemented errors for GPURenderPipeline creation (r247764)
Added descriptive error messages in WHLSL (r247834)
Changed checker to setError() when a property access node can’t commit its base type in WHLSL (r247676)
Changed to return the zero-value enum in the enum-from-integer constructor when the integer is not a valid enum value in WHLSL (r247675)
Made enums work in WHLSL (r247666)
Updated matrix memory layout to match HLSL by laying out columns linearly in WHLSL (r247468)

  Safari Technology Preview Release 89 released