Firefox 92 for developers

No changes

• The keywords avoid-page and avoid-column are now supported for the break-inside property (Firefox bug 1722945).
• The two-value syntax for the font-size-adjust property is now supported (Firefox bug 1720131).
• The size-adjust descriptor is now supported (Firefox bug 1720131).
• The CSS accent-color property has been implemented (Firefox bug 1722031).
• The system-ui value is now supported for the font-family property (Firefox bug 1226042).

• Object.hasOwn() can be used to test whether a property was defined on an object or inherited (Firefox bug 1721149).
• The default 5MB storage quota is now available to each origin. The quota previously applied to an entire domain group (also known as eTLD+1 domain; e.g., *.wikipedia.org). (Firefox bug 1064466).
• Storage quotas for Window.localStorage are now shared with IndexedDB API and Cache (Firefox bug 742822).

• Firefox will automatically upgrade an HTTP request to HTTPS when a usable HTTPS RR is available. It will also use information provided in an HTTPS RR to optimize the process of establishing HTTPS connections⁠—this is conceptually similar to using the Alt-Svc header. (Firefox bug 1721132).

• The disabledFeatures static property has been implemented for Custom Elements (Firefox bug 1723396).

DOM

• The Imperative Slotting API (part of the Shadow DOM API) Has been implemented. (Firefox bug 1705141)
• You can now monitor for changes to text selections in <input> or <textarea> by listening for selectionchange events in HTMLInputElement and HTMLTextAreaElement, respectively (Firefox bug 1648944).

Media, WebRTC, and Web Audio

• Access to audio output devices, like speakers and headphones, is now protected by the speaker-selection feature policy (Firefox bug 1577199).

• Improved support for the webSocketUrl capability, which now returns the WebDriver BiDi websocket URL if true was passed and if BiDi is supported. (Firefox bug 1692984).

• Support for cookieStoreId is added to downloads.download, downloads.DownloadQuery, and downloads.DownloadItem. The addition to the types downloads.DownloadQuery and downloads.DownloadItem provides support in downloads.search and downloads.erase. Web extensions can now associate downloads with specific cookie stores, such as container tabs (contextual identities). (Firefox bug 1669566)