Safari Technology Preview 250 is available for macOS Golden Gate and macOS Tahoe, covering WebKit changes between build 317507 and 317934. Highlights include new CSS properties (ruby-overhang: spaces, ::marker content, text-decoration-inset, white-space-trim, wrap-inside), removal of the non-standard CSS text color value in favor of canvastext, JavaScript support for Explicit Resource Management (using/await using, Symbol.dispose, DisposableStack) and Iterator.zip(), initial fetch() support for uploading ReadableStream bodies with a new duplex option on Request, WebAssembly relaxed SIMD and multiple memories support, plus numerous accessibility, scrolling, media, storage, and Web Inspector bug fixes.
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AccessibilityCSSEditingJavaScriptMediaNetworkingScrollingStorageWeb APIWeb InspectorWebAssemblyWebDriverQuestions this post answers
Does Safari Technology Preview 250 remove support for the non-standard CSS text color value?
Yes, Safari Technology Preview 250 removes support for the non-standard 'text' color value in CSS. Developers should use 'canvastext' instead, which is the standard equivalent. This change is part of the CSS deprecations listed for build 317687@main in Technology Preview 250. daily.dev helps developers catch CSS deprecations like this before they hit production.
Does Safari support the Explicit Resource Management proposal with using and await using in JavaScript?
Yes, Safari Technology Preview 250 adds support for the Explicit Resource Management proposal, including 'using' and 'await using' declarations, Symbol.dispose, DisposableStack, and AsyncDisposableStack. This lets developers manage resource cleanup deterministically in JavaScript and WebAssembly code running in WebKit. developers tracking new JavaScript proposals follow browser support updates like this on daily.dev.
Can I upload a ReadableStream body with fetch() in Safari Technology Preview 250?
Yes, Safari Technology Preview 250 adds initial support for uploading a ReadableStream body with fetch(), along with the required 'duplex' option on the Request object needed when streaming a request body. This brings WebKit closer to parity with other browsers on streaming fetch uploads. daily.dev keeps web developers current on fetch and streaming API support across browsers.
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