Firefox 107 release notes for developers

Changes for web developers

HTML

No notable changes

MathML

• Deprecated lquote and rquote attributes of the <ms> MathML element for custom opening and closing quotes are now disabled. This behavior is configured via the mathml.ms_lquote_rquote_attributes.disabled preference which is set to true by default (Firefox bug 1793387).

CSS

• The contain-intrinsic-size shorthand CSS property can now be applied to specify the size of a UI element that is subject to size containment. This allows a user agent to determine the size of an element without needing to render its child elements. The shorthand properties contain-intrinsic-width and contain-intrinsic-height are also supported, along with the logical properties contain-intrinsic-block-size and contain-intrinsic-inline-size. (Firefox bug 1597529).
• Color font is now supported via the font-palette property (Firefox bug 1791558). Support has also been added for the @font-palette-values CSS at-rule and its descriptors font-family, base-palette, and override-colors. Together they help to define the color palette (Firefox bug 1791558).

JavaScript

No notable changes

APIs

Removals

• The non-standard and deprecated SVGSVGElement.useCurrentView property has been removed. (See Firefox bug 1174097 for more details.)

WebDriver conformance (WebDriver BiDi, Marionette)

WebDriver BiDi

• Added Realm support to target argument for script.evaluate, script.callFunction, and script.disown commands (Firefox bug 1779231).

• Added support for JSON serialization of complex objects with container value fields, eg. WeakMap and Uint8Array (Firefox bug 1770754).

• Added support for the context parameter of the browsingContext.create command, which allows opening a new tab related to an existing one (Firefox bug 1765619).

• Improved reliability of the browsingContext.navigate command when called with the wait parameter set to none (Firefox bug 1763109).

Marionette

• The command WebDriver:ElementSendKeys now only sets the caret if the element is not focused yet (Firefox bug 1791736).

• Updated the command WebDriver:PerformAction to no longer accept undefined as value for various parameters of the pointerMove and wheel actions (Firefox bug 1781066).

• Updated the Selenium Atoms to match a recent WebDriver specification change (Firefox bug 1771942).

Changes for add-on developers

Other

• The error property returned when an error occurs in scripting.executeScript now represents any value the script throws or rejects with, instead of being just an object with a message property Firefox bug 1740608.