--- title: Safari Technology Preview 40 Release Notes framework: safari-technology-preview-release-notes role: article role_heading: Article path: safari-technology-preview-release-notes/stp-release-40 --- # Safari Technology Preview 40 Release Notes Preview the latest web technology updates including: JavaScript, FileSystem Entry API, Fetch API, Accessibility, Web API, CSS, CSS Grid, Web Inspector, Media, Rendering, and WebGL. ## Overview Overview Safari Technology Preview Release 40 is now available for download for macOS Sierra and betas of macOS High Sierra. If you already have Safari Technology Preview installed, you can update from the Mac App Store’s Updates tab. This release covers WebKit revisions 221334-221968. JavaScript Added support for regular expression named capture groups (r221769) Fixed semicolon tokens becoming interpreted as an = assignment operator (r221400) Implemented async iteration statement for-await-of (r221358) Optimized Object.keys using careful array allocation (r221853) FileSystem Entry API Added support for input.webkitEntries (r221645) Implemented FileSystemDirectoryEntry.getDirectory() (r221540) Implemented FileSystemEntry.getParent() (r221481) Implemented FileSystemFileEntry.file() (r221544) Fixed the FileSystemEntry API to ignore hidden files (r221639) Finished the DOMFormData implementation (r221839, r221914) Fetch API Added support for FetchRequest.body (r221395) Added support for Request body stream cloning (r221437) Added support for consuming a Request ReadableStream body (r221504) Added support for caching Response with a ReadableStream body (r221704) Aligned FetchResponse and FetchRequest body handling (r221772) Fixed Response.statusText unexpectedly using the full HTTP status line for HTTP/2 responses (r221804) Fixed Request ReadableStream body to throw an exception when keep alive is true (r221342) Accessibility Distinguished between title attribute tooltips and aria-label attribute labels (r221918) Web API Fixed validation for DOMMatrix and DOMMatrixReadOnly NaN values (r221545) Implemented DOMMatrix2DInit for setTransform() and addPath() (r221462) CSS Removed support for >> descendant combinator syntax (r221788) Fixed wrong getComputedStyle result for pseudo-elements in display:none subtrees. (r221542) Updated the font selection algorithm to match latest CSS specifications (r221630) CSS Grid Fixed grid shorthand to not reset the gutter properties (r221668) Changed stretching auto tracks to be done as part of the track sizing algorithm (r221931) Changed to use transferred size over content size for automatic minimum size (r221910) Web Inspector Fixed an issue that caused toolbar buttons to be hidden at narrow widths (r221338) Prevented the split console in the Settings tab (r221882) Use the same Timeline icon in the dashboard and Timeline tab (r221861) Increased the maximum width allowed for sidebars (r221713) Fixed an issue that prevented ⌘E and ⌘G from working in the main content area when quick console drawer is open (r221691) Media Prevented increasing the reported totalFrameDelay for non-displayed frames, or frames coming in while paused (r221937) Fixed MSE-to-Canvas painting that can become “stuck” during heavy workloads (r221430) Rendering Implemented the HTMLImageElement.async attribute (r221803) Implemented HTMLImageElement.decode() method (r221805) Fixed respecting the SVG fragment identifier if it is a part of an HTTP URL (r221377) Enabled previous elements with lang= to affect fonts selected for subsequent elements (r221408) WebGL Implemented getActiveUniforms() for WebGL 2 (r221667) Accelerated texImage2D for video doesn’t respect flipY (r221932) Fixed VideoTextureCopierCV to correctly restore vertex attribute state (r221933) ## See Also ### 2017 - [Safari Technology Preview 46 Release Notes](safari-technology-preview-release-notes/stp-release-46.md) - [Safari Technology Preview 45 Release Notes](safari-technology-preview-release-notes/stp-release-45.md) - [Safari Technology Preview 44 Release Notes](safari-technology-preview-release-notes/stp-release-44.md) - [Safari Technology Preview 43 Release Notes](safari-technology-preview-release-notes/stp-release-43.md) - [Safari Technology Preview 42 Release Notes](safari-technology-preview-release-notes/stp-release-42.md) - [Safari Technology Preview 41 Release Notes](safari-technology-preview-release-notes/stp-release-41.md) - [Safari Technology Preview 39 Release Notes](safari-technology-preview-release-notes/stp-release-39.md) - [Safari Technology Preview 38 Release Notes](safari-technology-preview-release-notes/stp-release-38.md) - [Safari Technology Preview 37 Release Notes](safari-technology-preview-release-notes/stp-release-37.md) - [Safari Technology Preview 36 Release Notes](safari-technology-preview-release-notes/stp-release-36.md) - [Safari Technology Preview 35 Release Notes](safari-technology-preview-release-notes/stp-release-35.md) - [Safari Technology Preview 34 Release Notes](safari-technology-preview-release-notes/stp-release-34.md) - [Safari Technology Preview 33 Release Notes](safari-technology-preview-release-notes/stp-release-33.md) - [Safari Technology Preview 32 Release Notes](safari-technology-preview-release-notes/stp-release-32.md) - [Safari Technology Preview 31 Release Notes](safari-technology-preview-release-notes/stp-release-31.md)