Undocumented browser bugs

[DmitrySharabin]

In Safari < 18.2, when transitioning not registered custom properties or custom properties of * or <string> data type,

• transitionend never fires
• without a delay: transitionrun and transitionstart fire infinitely
• with a delay: transitionstart never fires, transitionrun fires infinitely

See https://codepen.io/dmitrysharabin/full/xbKNPGJ

[DmitrySharabin]

In Safari < 18.2, there is no way to register a custom property of type <string> with any initial value. There will always be an error: The given initial value does not parse for the given syntax. 🤦‍♂️

Testcase: https://codepen.io/dmitrysharabin/pen/JoPQNJN

[LeaVerou]

In Safari < 18.2, there is no way to register a custom property of type <string> with any initial value. There will always be an error: The given initial value does not parse for the given syntax. 🤦‍♂️

Testcase: codepen.io/dmitrysharabin/pen/JoPQNJN

It looks like Safari may simply not support this type. Note that it gives the same error for any type it doesn't support, e.g.:

[yisibl]

Yes, WebKit for Safari 18.2 adds support for values of the syntax descriptor for @property.

• [@property] Support <string> syntax WebKit/WebKit#31755
• https://webkit.org/blog/16301/webkit-features-in-safari-18-2/
• https://webkit.org/blog/15798/release-notes-for-safari-technology-preview-202/

Chrome 131: https://chromestatus.com/feature/5083057057693696