Firefox 62 for developers
This article provides information about the changes in Firefox 62 that will affect developers. Firefox 62 was released on September 5, 2018.
Changes for web developers
Developer tools
- The Shape Path Editor is now available by default — see Edit Shape Paths in CSS for more information.
- You can now split the Rules view out into its own pane, separate from the other tabs on the CSS pane. See Page inspector 3-pane mode for more details.
- The Grid inspector has updated features, and all new documentation — see CSS Grid Inspector: Examine grid layouts.
- You now have four options for the location of the Developer Tools. In addition to the default location on the bottom of the window, you can choose to locate the tools on either the left or right sides of the main window or in a separate window (Firefox bug 1192642).
- A close button has been added to the split console toolbar.
- If the option to "Select an iframe as the currently targeted document" is checked, the icon will appear in the toolbar while the Settings tab is displayed, even if the current page doesn't include any iframes (Firefox bug 1456069).
- The Network Monitor's Cookies tab now shows the cookie
samesite
attribute (Firefox bug 1452715). - Responsive design mode now works inside container tabs (Firefox bug 1306975).
- When CORS errors occur and are reported on the console, Firefox now provides a link to the corresponding page in our CORS error documentation (Firefox bug 1475391).
- Create a screenshot of the current page (with an optional filename) from the Console tab (Firefox bug 1464461) using the following command:
wherebash
:screenshot <filename.png> --fullpage
<filename.png>
is the desired filename. The file will be saved to your downloads folder. The--fullpage
parameter is optional, but if included, it will save the full web page. This option also adds-fullpage
to the name of the file. For a list of all options available for this command, enter::screenshot --help
Removals
- The Developer Toolbar/GCLI (accessed with
Shift
+F2
), has been removed from Firefox (Firefox bug 1461970). Both the Developer Toolbar UI and the GCLI upstream library have become unmaintained, some of its features are broken (some ever since e10s), it is blocking theunsafeSetInnerHTML
work, usage numbers are very low, alternatives exist for the most used commands.
HTML
No changes.
CSS
:-moz-selection
has been unprefixed to::selection
(Firefox bug 509958).x
is now supported as a unit for the<resolution>
type (Firefox bug 1460655).shape-margin
,shape-outside
, andshape-image-threshold
are now enabled by default (Firefox bug 1457297).
Removals
- All XUL
display
values with the exception of-moz-box
and-moz-inline-box
have been removed from non-XUL documents in Firefox bug 1288572.
SVG
No changes.
JavaScript
- The
WebAssembly.Global()
constructor is now supported, along with global variables in WebAssembly (Firefox bug 1464656). - The
Array.prototype.flat()
andArray.prototype.flatMap()
methods are now enabled by default (Firefox bug 1435813). - The
import.meta
property has been implemented to expose context-specific metadata to a JavaScript module (Firefox bug 1427610). - JavaScript string literals may now directly contain the U+2028 LINE SEPARATOR and U+2029 PARAGRAPH SEPARATOR characters. As a consequence,
JSON
syntax is now a subset of JavaScript literal syntax (see Firefox bug 1435828 and the TC39 proposal json-superset). - For out-of-bounds typed array indexes,
Reflect.defineProperty()
andReflect.set()
will now returnfalse
instead oftrue
(Firefox bug 1308735).
Removals
- The
DOMPoint
andDOMPointReadOnly
constructors no longer support an input parameter of typeDOMPointInit
; the values of the properties must be specified using thex
,y
,z
, andw
parameters (Firefox bug 1186265). - The
URL.createObjectURL()
method no longer supports creating object URLs to represent aMediaStream
. This capability has been obsolete for some time, since you can now setHTMLMediaElement.srcObject
to theMediaStream
directly (Firefox bug 1454889).
APIs
New APIs
- The Speech Synthesis API (Text-to-Speech) is now enabled by default on Firefox for Android (Firefox bug 1463496).
DOM
- The
DOMPointReadOnly
interface now supports the static functionDOMPointReadOnly.fromPoint()
, which creates a new point object from a dictionary that's compatible withDOMPointInit
, which includes anyDOMPoint
object. This function is also available onDOMPoint
(Firefox bug 1186265). - For compatibility purposes, the
Event.srcElement
property is now supported. It is an alias forEvent.target
(Firefox bug 453968). Navigator.registerProtocolHandler()
now must only be called from a secure context (Firefox bug 1460506).- The
Navigator.registerContentHandler()
method has been disabled by default in preparation for being removed entirely, as it's been obsolete for some time (Firefox bug 1460481). - The
DataTransfer()
constructor has been implemented (Firefox bug 1351193). Document.domain
can no longer returnnull
(Firefox bug 819475). If the domain cannot be identified, thendomain
returns an empty string instead ofnull
.- Added the
console.timeLog()
method to display the current value of a console timer while continuing to track the time (Firefox bug 1458466). - Added
console.countReset()
to reset a console counter value (Firefox bug 1459279).
DOM events
No changes.
Service workers
No changes.
Media, Web Audio, and WebRTC
- The
"media.autoplay.enabled"
preference now controls automatic playback of both audio and video media, instead of just video media (Firefox bug 1413098). - The
ChannelSplitterNode
has been fixed to correctly default to having 6 channels with thechannelInterpretation
set to"discrete"
and thechannelCountMode
set to"explicit"
, as per the specification (Firefox bug 1456265).
Removals
- The
userproximity
anddeviceproximity
events, as well as theUserProximityEvent
andDeviceProximityEvent
interfaces, have been disabled by default behind thedevice.sensors.proximity.enabled
preference (Firefox bug 1462308). - The
devicelight
event of typeDeviceLightEvent
has been disabled by default behind thedevice.sensors.ambientLight.enabled
preference (Firefox bug 1462308). - The
DOMSubtreeModified
andDOMAttrModified
mutation events are no longer thrown when thestyle
attribute is changed via the CSSOM (Firefox bug 1460295. - Support for
CSSStyleDeclaration.getPropertyCSSValue()
has been removed (Firefox bug 1408301). - Support for
CSSValue
,CSSPrimitiveValue
, andCSSValueList
has been removed (Firefox bug 1459871). window.getComputedStyle()
no longer returnsnull
when called on aWindow
which has no presentation (Firefox bug 1467722).
HTTP
Removals
- The deprecated CSP
referrer
directive has been removed. Please use theReferrer-Policy
header instead (Firefox bug 1302449).
Security
No changes.
Plugins
No changes.
WebDriver conformance (Marionette)
New features
- Command
WebDriver:ElementSendKeys
has been made WebDriver conforming for file uploads (Firefox bug 1448792). - User prompts as raised by
beforeunload
events are automatically dismissed forWebDriver:Get
,WebDriver:Back
,WebDriver:Forward
,WebDriver:Refresh
, andWebDriver:Close
commands (Firefox bug 1434872). WebDriver:PerformActions
forCtrl
+Click
synthesizes acontextmenu
event (Firefox bug 1421323).
API changes
- Removed obsolete endpoints including
getWindowPosition
,setWindowPosition
,getWindowSize
, andsetWindowSize
(Firefox bug 1348145). - WebDriver commands which return success with data
null
now return an empty dictionary (Firefox bug 1461463).
Bug fixes
WebDriver:ExecuteScript
caused cyclic reference error for WebElement collections (Firefox bug 1447977).- Dispatching a
pointerMove
orpause
action primitive could cause a hang, and the command to never send a reply (Firefox bug 1467743, Firefox bug 1447449).
Other
No changes.
Changes for add-on developers
API changes
- Added the
webRequest.getSecurityInfo()
API to examine details of TLS connections (Firefox bug 1322748). - Added the
browserSettings.newTabPosition
to customize where new tabs open (Firefox bug 1344749). windowTypes
has been deprecated inwindows.get()
,windows.getCurrent()
, andwindows.getLastFocused()
(Firefox bug 1419132).- It's now possible to modify a browser action on a per-window basis (Firefox bug 1419893).
Manifest changes
- New
open_at_install
property of thesidebar_action
manifest key enables extensions to control whether their sidebars should open automatically on install or not (Firefox bug 1460910). - Changes to the
browser_style
property of various manifest keys:- In
page_action
andbrowser_action
it defaults tofalse
. - In
sidebar_action
andoptions_ui
it defaults totrue
.
- In
Theme changes
- New
tab_background_separator
property of thetheme
manifest key enables extensions to change the color of the tab separator (Firefox bug 1459455).
Removals
- Support for unpacked sideloaded extensions has been removed (Firefox bug 1385057).
- The warning about
browser_style
displayed when temporarily loading an extension for testing is no longer displayed (Firefox bug 1404724).
Older versions
- Firefox 61 for developers
- Firefox 60 for developers
- Firefox 59 for developers
- Firefox 58 for developers
- Firefox 57 for developers
- Firefox 56 for developers
- Firefox 55 for developers
- Firefox 54 for developers
- Firefox 53 for developers
- Firefox 52 for developers
- Firefox 51 for developers
- Firefox 50 for developers
- Firefox 49 for developers
- Firefox 48 for developers
- Firefox 47 for developers
- Firefox 46 for developers
- Firefox 45 for developers
- Firefox 44 for developers
- Firefox 43 for developers
- Firefox 42 for developers
- Firefox 41 for developers
- Firefox 40 for developers
- Firefox 39 for developers
- Firefox 38 for developers
- Firefox 37 for developers
- Firefox 36 for developers
- Firefox 35 for developers
- Firefox 34 for developers
- Firefox 33 for developers
- Firefox 32 for developers
- Firefox 31 for developers