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# Safari Technology Preview 118 Release Notes

Preview the latest web technology updates including: Web Inspector, CSS, Scrolling, JavaScript, WebGL, Media, Private Click Measurement, WebRTC, Web API, Accessibility, and Extensions.

## Overview

[Safari Technology Preview](https://webkit.org/blog/6017/introducing-safari-technology-preview/) Release 118 is now [available for download](https://webkit.org/downloads/) for macOS Big Sur and macOS Catalina. If you already have Safari Technology Preview installed, you can update in the Software Update pane of System Preferences on macOS.

This release covers WebKit revisions [270230-270749](https://trac.webkit.org/log?stop_rev=270230&rev=270749&limit=999).

### Web Inspector

- Elements
  - Added an experimental Font details sidebar panel for showing information about the currently used font of the selected node  ([r270637](https://trac.webkit.org/changeset/270637/webkit/))
- Sources
  - Added support for intercepting and overriding network requests ([r270604](https://trac.webkit.org/changeset/270604/webkit/))

### CSS

- Implemented Definite and Indefinite Sizes in flexbox ([r270578](https://trac.webkit.org/changeset/270578/webkit/))
- Corrected cases in which `box-sizing` was `border-box` and didn’t use the content box to compute size based on aspect ratio ([r270617](https://trac.webkit.org/changeset/270617/webkit/))
- Fixed preserving aspect ratio when computing cross size of flexed images in `auto-height` flex container ([r270288](https://trac.webkit.org/changeset/270288/webkit/))
- Added support for `aspect-ratio` on replaced and non-replaced elements ([r270551](https://trac.webkit.org/changeset/270551/webkit/), [r270618](https://trac.webkit.org/changeset/270618/webkit/))
- Changed `text-decoration-color` animation not to be discrete ([r270597](https://trac.webkit.org/changeset/270597/webkit/))
- Changed `getComputedStyle` rounding `lineHeight` to nearest pixel ([r270248](https://trac.webkit.org/changeset/270248/webkit/))
- Changed to trigger web font loads earlier ([r270590](https://trac.webkit.org/changeset/270590/webkit/))

### Scrolling

- Made only the first wheel event in a gesture to be cancelable ([r270425](https://trac.webkit.org/changeset/270425/webkit/))

### JavaScript

- Enabled “at” methods ([r270550](https://trac.webkit.org/changeset/270550/webkit/))
- Changed `get` and `set` for object literal and class to not be escaped ([r270487](https://trac.webkit.org/changeset/270487/webkit/))
- Accepted escaped keywords for class and object property names ([r270481](https://trac.webkit.org/changeset/270481/webkit/))
- Aligned `%TypedArray%` constructor/slice behavior with the specification strictly ([r270552](https://trac.webkit.org/changeset/270552/webkit/), [r270371](https://trac.webkit.org/changeset/270371/webkit/))
- Added a JSC API to allow acquiring the `JSLock` to accelerate performance ([r270659](https://trac.webkit.org/changeset/270659/webkit/))
- Removed unnecessary `JSLock` use from various JSC APIs ([r270665](https://trac.webkit.org/changeset/270665/webkit/))
- Aligned `[[DefineOwnProperty]]` method of mapped arguments object with the specification strictly ([r270664](https://trac.webkit.org/changeset/270664/webkit/))
- Changed `Reflect.preventExtensions` not throwing if called on `WindowProxy` or `Location`  ([r270702](https://trac.webkit.org/changeset/270702/webkit/))

### WebGL

- Fixed rasterizer discard interfering with implicit clears in WebGL 2 ([r270253](https://trac.webkit.org/changeset/270253/webkit/))

### Media

- Implemented WebVTT VTTCue region attribute ([r270738](https://trac.webkit.org/changeset/270738/webkit/))

### Private Click Measurement

- Exposed an API for enabling or disabling Private Click Measurement ([r270710](https://trac.webkit.org/changeset/270710/webkit/))

### WebRTC

- Added support for `RTCRtpSender::setStreams` ([r270486](https://trac.webkit.org/changeset/270486/webkit/))
- Enabled use of new socket API for WebRTC TLS connections by default ([r270680](https://trac.webkit.org/changeset/270680/webkit/))
- Fixed ICE not resolving for `turns` relay candidates rooted in LetsEncrypt CA ([r270626](https://trac.webkit.org/changeset/270626/webkit/))
- Improved RTCRtpSender and RTCRtpReceiver transforms support ([r270641](https://trac.webkit.org/changeset/270641/webkit/), [r270290](https://trac.webkit.org/changeset/270290/webkit/), [r270294](https://trac.webkit.org/changeset/270294/webkit/), [r270507](https://trac.webkit.org/changeset/270507/webkit/), [r270532](https://trac.webkit.org/changeset/270532/webkit/))
- Introduced an experimental flag specific to VP9 profile 2 ([r270256](https://trac.webkit.org/changeset/270256/webkit/))

### Web API

- Changed to allow blob URLs with fragments ([r270269](https://trac.webkit.org/changeset/270269/webkit/))
- Fixed lazy loaded iframe to not lazy load when scripting is disabled ([r270300](https://trac.webkit.org/changeset/270300/webkit/))
- Changed `Reflect.preventExtensions` to not throw if called on `WindowProxy` or `Location` ([r270702](https://trac.webkit.org/changeset/270702/webkit/))
- Changed `sessionStorage` to not be cloned when a window is opened with `rel=noopener` ([r270273](https://trac.webkit.org/changeset/270273/webkit/))
- Updated the list of blocked ports according fetch specification ([r270321](https://trac.webkit.org/changeset/270321/webkit/))

### Accessibility

- Fixed VoiceOver not announcing the `aria-checked` state for ARIA `treeitem` ([r270333](https://trac.webkit.org/changeset/270333/webkit/))

### Extensions

- Fixed the `onClicked` listener not being called for page actions

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