Firefox 119 release notes for developers

This article provides information about the changes in Firefox 119 that affect developers. Firefox 119 was released on October 24, 2023.

Changes for web developers

HTML

Removals

• The {{HTMLElement('input')}} element no longer supports the non-standard mozactionhint attribute. Use enterkeyhint instead. (See Firefox bug 1735980 for more details.)

CSS

• The {{cssxref("attr")}} CSS function fallback value is now supported. This allows the setting of a fallback value to be used if the global attribute is missing (Firefox bug 1448248).

JavaScript

• The {{jsxref("Object.groupBy()")}} and {{jsxref("Map.groupBy()")}} static methods for grouping the elements of an iterable are now supported (See Firefox bug 1792650 for more details.)
• The {{jsxref("String.prototype.isWellFormed()")}} and {{jsxref("String.prototype.toWellFormed()")}} methods respectively can be used to check if a string contains well-formed Unicode text (i.e., contains no lone surrogates) and sanitize an ill-formed string to well-formed Unicode text. (See Firefox bug 1850755 for more details).

SVG

• The SVG attributes that accept a <length> value now support level 3 {{cssxref("length")}} CSS data types for all SVG elements. This enables the sizing of SVG elements based on font sizes (cap, rem, etc.), viewport (vh, vw, vmin, etc.), or absolute lengths (px, cm, etc.), e.g., <line x1="10vw" y1="10vh" x2="50vw" y2="50vh"/>. (See Firefox bug 1287054 for more details).

HTTP

• The credentialless directive of the {{HTTPHeader("Cross-Origin-Embedder-Policy")}} HTTP response header is now supported on desktop platforms (and mobile platforms other than Android), allowing no-cors requests for resources to be made on cross-origin servers that have not explicitly opted into it, albeit without cookies or other credentials (Firefox bug 1851467).

APIs

• The relative priority for send streams can now be specified by including the sendOrder property inside an options argument passed to WebTransport.createBidirectionalStream() and WebTransport.createUnidirectionalStream() (Firefox bug 1816925).
• The getAuthenticatorData(), getPublicKeyAlgorithm(), and getPublicKey() methods of the AuthenticatorAttestationResponse interface are now supported (see Firefox bug 1816519 and Firefox bug 1816520).
• The Credential Properties Extension (credProps) of the Web Authentication API is supported, allowing users to query if credentials are discoverable after creation/registration (Firefox bug 1844437).
• The SubtleCrypto.deriveKey() method now supports the HKDF algorithm as an option for its derivedKeyType parameter (see Firefox bug 1851928).
• The {{domxref("PublicKeyCredential.parseCreationOptionsFromJSON_static", "parseCreationOptionsFromJSON()")}}, {{domxref("PublicKeyCredential.parseRequestOptionsFromJSON_static", "parseRequestOptionsFromJSON()")}}, and {{domxref("PublicKeyCredential.toJSON", "toJSON()")}} methods of the {{domxref("PublicKeyCredential")}} interface are now supported. These are convenience methods for converting objects used for creating and sharing credentials objects to JSON representations that can be serialized/deserialized and shared with a server (see Firefox bug 1823782).

DOM

• ARIA reflection is now supported by default for attributes that do not reference other elements; only non-ID-reference attributes are reflected. You can now get and set ARIA attributes on DOM elements directly via JavaScript APIs, rather than by using setAttribute and getAttribute. For example, buttonElement.ariaPressed = "true"; is now supported in addition to buttonElement.setAttribute("aria-pressed", "true"); (Firefox bug 1785412).

WebDriver conformance (WebDriver BiDi, Marionette)

General

• When performing a pointerDown action with the middle or right mouse button pressed, the mousedown event as emitted by the related HTML element had the value of the buttons property swapped (Firefox bug 1850086).

• When performing a scroll action of input type wheel with an origin set to pointer an invalid argument error was inappropriately raised, whereas per the current WebDriver specification this combination is not supported (Firefox bug 1850166).

WebDriver BiDi

• Added the browsingContext.reload command that allows users to reload the page or a frame that is currently displayed within a given browsing context (Firefox bug 1830859).

• Added the browsingContext.userPromptClosed event that is emitted when a user prompt of type alert, confirm, or prompt got closed (Firefox bug 1824221).

• Added the browsingContext.navigationStarted event that is emitted when a new navigation is started by Firefox (Firefox bug 1756595).

• Added the script.realmCreated and script.realmDestroyed events that allow users to monitor the lifetime of JavaScript Realms of a given browsing context. Such a Realm is basically an isolated execution environment (sandbox) with its own unique global object (window) (Firefox bug 1788657, Firefox bug 1788659).

• The browsingContext.userPromptOpened event was accidentally sent when a HTTP Authentication dialog was opened (Firefox bug 1853302).

• Unwanted events with the context field set to null will no longer be emitted. Because the underlying browsing context has been closed such events are no longer valid (Firefox bug 1847563).

Marionette

• The list of possible error codes when trying to install a WebExtension by using the Addon:Install command has been updated to match the latest error codes of Firefox (Firefox bug 1852537).