Categories: News

These Weeks in Firefox: Issue 42


  • New Onboarding experience in Firefox 62 currently only as an experiment.
    • The onboarding critters when first starting up Firefox

      Totally adorable onboarding critters (Scientific name: Totes Adorbs Familiaris)

  • The new about:policies helps administrators verify if they have configured policies correctly, learn more about the different policies, and resolve errors.

    • The new about:policies page, showing which policies are enabled by system administrators

      about:policies, coming soon!

  • About:performance UI is currently being updated, currently behind a pref more details in the bug 1477677
    • The new about:performance page showing a table of open tabs ordered by how much they're impacting system resource usage

      The new about:performance will show you what pages are draining your system resources

  • Doug Thayer pushed the ClientStorage work through the finish line! This should improve responsiveness and (maybe) power usage on macOS. This should also allow tab warming to ride to release on macOS!

Project Updates

Add-ons / Web Extensions

Browser Architecture

  • XUL/XBL Replacement Newsletter #6 posted.
  • Browser console is now loaded as a html document.
  • getElementsByAttribute[NS] now works on (chrome) HTML documents.
  • Added document.createXULElement. No namespace funkiness!
  • Working on a plan to either remove broadcaster/observers or support them in HTML.
  • Investigating feasibility of landing rkv as NPOTB so potential consumers can investigate it for suitability to their use cases (bug 1445451).


  • We are switching most ChromeUtils.import calls to be treated as explicit variable declarations by ESLint. This has the advantage of triggering no-unused-vars more often (especially in jsm files), to find unused imports.
    • This doesn’t work where modules.json lists a file as exporting two symbols (only one of them might be used, so we haven’t weeded them out yet).
    • The better form declarations of const {Foo} = ChromeUtils.import(“resource://foo.jsm”, {}); are already handled according to the variables.


Policy Engine

  • About:policies page (Bug 1472528) – Kanika Saini
    • Active Policies
      • Policies vary a lot
        • Some are just boolean values, for e.g DisableAppUpdate
        • Some are arrays of objects with keys and values, for e.g. Bookmarks
        • Some are objects which have keys and their values have arrays in a deeper level, for e.g Permissions
    • Documentation

      • Showing the built-in documentation in about:policies

        The documentation is built-in! Alright!

        Showing the schemas for some policies inside the about:policies built-in documentation

        Showing off the schema for some policies

      • Machine-only icon warns the administrator about such policies
      • Each policy row is a collapsible which on click expands to display more information about the policy, for e.g schema for the policy
    • Errors
      • Showing the error interface in about:policies, with some example errors in it.

        When things go wrong with policy management, error messages go here.

      • Error tab is only visible when there is an error
      • Gives a brief of the error relating to the Policy Engine only

Search and Navigation

Address Bar & Search


Test Pilot

  • Side View is a hit!
    • MAU graph:

      Showing a MAU graph of our Test Pilot users

      Side View seems to be pretty popular with our Test Pilot users.

    • Next for Side View: added to Shield queue
  • Screenshots
    • New annotations features shipped! Undo/Redo (Barry) & Text tool (Punam)
    • Current sprint is mostly server-focused:
      • Finishing the last few bugs on new features, minor release later this week
      • Starting work on a redesign with tighter FxA integration & better accessibility
        • Soon: work with Kimberly from accessibility team to add accessibility testing to our Selenium tests
    • Client updates:
      • Bootstrap removal work continues
        • Telemetry API for internal WebExtensions got R+, will be landing soon
      • Adding Barry and Punam as peers on the Firefox Screenshots module

Web Payments

  • Working through final bugs before WebPayments goes through user testing.
  • Prathiksha finished her internship last week. We are very grateful for her contributions!

One comment on “These Weeks in Firefox: Issue 42”

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  1. Jay wrote on

    Great work, love the stuff you are doing with about:policies and the new enterprise policies. 🤓 Keep it up!


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