Urlbar Top Sites Experiment Extension

This is the extension for the urlbar top sites add-on experiment. When installed, focusing Firefox's urlbar automatically opens the urlbar view and shows the top sites from your new-tab page. (Two caveats: The view does not automatically open when the current tab is the new-tab page itself since it already shows your top sites. It also doesn't open in private windows.)

Bug 1547279 is the meta bug that tracks this experiment.

Requirements

• Firefox 69b13 or newer
• Either a Mozilla-signed version of the add-on; or Firefox Nightly, Developer Edition, or any other Firefox build that gives privileges to temporarily installed add-ons (Beta does not). This add-on uses Mozilla-privileged APIs (browser.urlbar and browser.normandyAddonStudy)

Running

You can use web-ext or about:debugging. Both will load the add-on as a temporary add-on, so you'll need to use Firefox Nightly, Developer Edition, or any other Firefox build that gives privileges to temporarily installed add-ons.

Building

Use web-ext to build the add-on zip file.

Testing

The tests directory contains a browser chrome mochitest and a head.js. The head.js implements a simple framework for testing Normandy experiment add-on files.

The requirements above for running the add-on apply to testing it, too. You'll need either a Mozilla-signed version of the add-on; or Firefox Nightly, Developer Edition, or any other Firefox build that gives privileges to temporarily installed add-ons.

To run the test in a particular version of Firefox, you'll need to clone the repo from which your Firefox was built. If you're testing in Nightly 70, you'll need mozilla-central. If you're testing in Developer Edition 69 or Beta 69, you'll need mozilla-beta.

Then:

1. cd into your urlbar-top-sites-experiment clone.

2. Copy tests/* into srcdir/testing/extensions/, where srcdir is the top-level directory of your Firefox repo:

   $ cp -R tests/* srcdir/testing/extensions
   

3. Build the add-on zip file using web-ext as described above:

   $ web-ext build
   

   Or use a signed copy of the zip file.

4. Copy the zip file into srcdir/testing/extensions/tests/browser:

   $ cp web-ext-artifacts/urlbar_top_sites_experiment-1.0.0.zip srcdir/testing/extensions/tests/browser
   

5. Update EXPECTED_ADDON_SIGNED_STATE as necessary in srcdir/testing/extensions/tests/browser/browser_urlbarTopSitesExtension.js. If your zip file is unsigned, its value should be AddonManager.SIGNEDSTATE_MISSING. If it's signed, it should be AddonManager.SIGNEDSTATE_PRIVILEGED.

6. cd into your srcdir.

7. Run the test using mach:

   $ ./mach mochitest -f browser --appname <path to Firefox binary> testing/extensions/tests/browser/browser_urlbarTopSitesExtension.js
   

   If your Firefox repo itself contains the Firefox binary (because you ran mach build), you can omit the --appname argument.

   If mach doesn't find the test, remove your objdir, mach build, and try again from step 1. (There's got to be a better way…)

Linting

This project uses the linting rules from mozilla-central. From your urlbar-top-sites-experiment directory, run:

$ npm install
$ npx eslint .