Screenshot of a new Firefox Profiler context menu option, particularly for viewing a source file called Interpreter.cpp.
Categories: News

A Variety of Improvements At January’s End – These Weeks in Firefox: Issue 131


Screenshot of the about:logins page before new UI changes, where login updates where simply displayed as text at the bottom of the page.

      • After:

Screenshot of the about:logins page after new UI changes, where a new timeline visual is now visible at the bottom of the page to indicate when a login was last updated.

  • Picture-in-Picture updates:
    • kpatenio updated the Dailymotion wrapper, so captions should appear again on the PiP window
    • kpatenio resolved issues where PiP touch events changed playback while toggling PiP
    • Niklas fixed the Netflix wrapper when seeking forward or backward and scrubbing
    • Niklas increased the seek bar slider clickable area, making it easier to select the scrubber with the mouse
  • The DevTools team have updated our main highlighters to use less aggressive styling when prefers-reduced-motion is enabled (bug)

A screenshot of the DevTools' new highlighter appearing on the Wikipedia landing page when a user enables the setting prefers-reduced-motion.

  • There is a new context menu option for opening source view in Firefox Profiler. Thanks to our contributor Krishna Ravishankar!

Screenshot of a new Firefox Profiler context menu option, particularly for viewing a source file called Interpreter.cpp.

Friends of the Firefox team


  • [mconley] Introducing Jonathan Epstein (jepstein) who is coming to us from the Rally team as a new Engineering Manager! Welcome!

Resolved bugs (excluding employees)

Volunteers that fixed more than one bug
  • CanadaHonk [:CanadaHonk]
  • Gregory Pappas [:gregp]
  • Jonas Jenwald [:Snuffleupagus]
  • kernp25
  • Oriol Brufau [:Oriol]
New contributors (🌟 = first patch)

Project Updates

Add-ons / Web Extensions

WebExtension APIs
  • Oriol Brufau contributed a fix to the “tabs.move” API method when used to move multiple tabs into a different browser window – Bug 1809364
  • Gregory Pappas contributed a new “matchDiacritics” option to the (Firefox-specific) find API – Bug 1680606
  • All manifest_version 3 extensions that want to use the “webRequest.filterResponseData” API method will have to request the new “webRequestFilterResponse” permission (in addition to the “webRequest” and “webRequestBlocking” permissions that were already needed to get access to this API in manifest_version 2 extensions) – Bug 1809235
  • declarativeNetRequest API:
    • Constants representing the values, used internally to enforce limits to the DNR rules that each extension is allowed to define and enable, are now exposed as declarativeNetRequest API namespace properties – Bug 1809721
    • Update JSONSchema and tests to explicitly cover the expected default value set for the DNR rule condition property “isUrlFilterCaseSensitive”, which should be false per consensus reached in the WECG (WebExtensions Community Group) – Bug 1811498
  • As part of tweaks that aim to reduce the number of changes needed to port a Chrome’s manifest_version 3 extension to Firefox, In Firefox >= 110 the optional “extension_ids” property part of the manifest_version 3 “web_accessible_resources” manifest property can be set to an empty array – Bug 1809431
WebExtensions Framework
  • Extensions button and panel:
    • Cleanups for the remaining bits of the legacy implementation (which also covered the removal of the pref) – Bug 1799009, Bug 1801540
    • Introduction of a new “Origin Controls” string to be shown to the users in the extensions panel when an extension has access to the currently active tab but limited to the current visit (which will only be valid while the tab is not navigated) – Bug 1805523

Developer Tools

  • Thanks to Tom for grouping CSP warnings in the console (bug)

A screenshot showcasing more descriptive Content Security Policy, alias CSP, warnings on the browser console.

  • Thanks to rpl for fixing dynamic updates of the extension storage in the Storage panel (bug)
  • Alex fixed a recent regression for the Browser Toolbox in parent process mode, where several panels would start breaking when doing a navigation in the Browser (bug)
  • Alex also fixed several issues in the Debugger for sources created using `new Function` (eg bug)
  • Nicolas fixed several bugs for the autocomplete in the Browser Toolbox / Console, which could happen when changing context in the context selector (bug and bug)
WebDriver BiDi
  • Thanks to :CanadaHonk for fixing bugs or adding missing features in our CDP implementation (bug, bug, bug, bug, bug)
  • Henrik updated events of the browsingContext module (eg `domContentLoaded`, `load`, …) to provide a timestamp, which can be useful to collect page performance data (bug)
  • Sasha updated our vendored Puppeteer to version 18.0.0, which now includes a shared test expectation file, which means less maintenance for us and a better test coverage for Firefox on puppeteer side (bug and bug).
  • We implemented the network.responseCompleted event (bug) and updated our example web-client for webdriver BiDi to provide a simplified version of a network monitor (

ESMification status

  • ESMified status:
    • browser: 46.1%
      • Dropped a little bit because we removed a large number of sys.mjs files we didn’t need any more.
    • toolkit: 38.3%
      • Bilal has been working on migrating various actors.
    • Total: 46.54% (up from 46.0%)
  • #esmification on Matrix
  • Migration Document (with a walkthrough!)

Lint, Docs and Workflow

Migration Improvements (CalState LA Project)


Performance Tools (aka Firefox Profiler)

  • Support zip files on windows. Thanks to our contributor Krishna Ravishankar!
  • Scroll item horizontally in the virtuallist, taking into account the fixed size.
  • Remove the “optimizations” field from the frame table. This should reduce our profile data size.
  • Allow pinning source code view files to specific git tags.
  • Enable screenshots on talos profiling jobs on treeherder.
  • Remove some Timestamp::Now calls when the profiler is not running.
  • Fix Firefox version inside the profile data.

Search and Navigation

Storybook / Reusable components

A screenshot of the about:addons page displaying details about an add-on called "Tree Style Tab" and showcasing moz-toggle components in use.

  • Bug 1809457 –  Our common stylesheet no longer conflicts with Storybook styles
  • Bug 1801927 – The “Learn more” links in the about:preferences#general tab have been updated to use `moz-support-link`
  • Bug 1803155 (Heading to autoland) – ./mach storybook install is going away in favor of automatically installing dependencies when ./mach storybook is run

One comment on “A Variety of Improvements At January’s End – These Weeks in Firefox: Issue 131”

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  1. Heo Jin Yeong wrote on

    I’m using Firefox browser well. I am using three browsers: Naver Whale, Microsoft Edge, and Firefox, and I am using one of the top three browsers recommended by the world. The release prefers beta or Nightly versions to the full version. Although it is not a stable version, I think the future of the Internet is to experience the browser and help the browser grow.


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