Firefox 109 release notes for developers

Changes for web developers

HTML

• The range element supports the list attribute, which links via an id to a <datalist> to allow Firefox to display tick marks along the range.

CSS

• The <system-color> CSS data type now supports the values Mark, MarkText, and ButtonBorder (Firefox bug 1638052).

JavaScript

No notable changes.

SVG

Removals

• SVGGraphicsElement.getTransformToElement() has been removed. This follows its removal from the SVG2 specification in 2015, and from other major browsers. (Firefox bug 1803790).

• The SVGGraphicsElement.nearestViewportElement and SVGGraphicsElement.farthestViewportElement attributes have been disabled by default in nightly and early beta builds (behind preference svg.nearestAndFarthestViewportElement.enabled). SVGElement.viewportElement can be used as an alternative to SVGGraphicsElement.nearestViewportElement. They have been removed from the SVG2 specification and are likely to be removed entirely from Firefox in a future release. (Firefox bug 1133174).

HTTP

• The 'unsafe-hashes' value for Content-Security-Policy source directives is now supported. For more information, see CSP unsafe-hashes (Firefox bug 1343950).

APIs

DOM

• The scrollend events are now supported, which indicate that the user has completed scrolling in Element and Document objects. For more information, see Element: scrollend event and Document: scrollend event (Firefox bug 1797013, Firefox bug 1803435).

WebDriver conformance (WebDriver BiDi, Marionette)

WebDriver BiDi

• The connection details for WebDriver BiDi are now written to WebDriverBiDiServer.json instead of WebDriverBiDiActivePort, which contains both the port (ws_port) and the host (ws_host). This file is located in the Firefox profile folder (Firefox bug 1792875).
• Added support for subscribing / unsubscribing to individual contexts when using session.subscribe and session.unsubscribe (Firefox bug 1723102).
• Added support for serializing Node objects (Firefox bug 1770731).
• Fixed the columnNumber for exceptions and stackTraces to be 0-based (Firefox bug 1796073).

Marionette

• Fixed a bug where WebDriver:NewWindow and WebDriver:SwitchToWindow were not focusing the new window properly (Firefox bug 1798655).
• Fixed a bug where WebDriver:FindElement (and similar commands) would fail if the Firefox window was occluded by other applications on Windows (Firefox bug 1802473).

Changes for add-on developers

• Manifest V3 is now supported with the ability to sign and release Manifest V3 extensions on AMO. See the Manifest v3 signing available November 21 on Firefox Nightly blog post for more information. The following preview features are now fully available:

  • The scripting API, although this has been available to Manifest V2 extensions from Firefox 102.
  • The action API, and "action" manifest key and _execute_action special shortcut in the manifest commands key.
  • The "host_permissions" manifest key.

• The default Content Security Policy (CSP) for Manifest V3 extensions has been updated to include upgrade-insecure-requests. This means that, by default, all network requests are upgraded to use https:. Extensions that need to use http: can do so by overriding the default CSP using the content_security_policy manifest.json key (Firefox bug 1797086).

• The property secretKeyLength has been added to webRequest.SecurityInfo. This property provides the length in bits of the secret key in the security properties of a web request (Firefox bug 1778473).

• With the introduction of the extensions button, the default value of default_area in the action and browser_action manifest keys has changed from "navbar" to "menupanel" (Firefox bug 1799947).

• Support for omnibox.onDeleteSuggestion and the deletable property in omnibox.SuggestResult, enabling extensions to react to a user deleting an address bar search result (Firefox bug 1799947).

• Support for the top and left parameters to determine positioning of panel or popup window using windows.create() (Firefox bug 1271047).