no-newtab-refs-outside-newtab

Prevents the use of chrome://newtab or resource://newtab URIs from code outside of the newtab codebase. This is because as of Firefox 142, newtab can be updated out-of-band from the rest of the browser. This linting rule aims to prevent accidental dependencies from being created against a moving newtab target. If external code _must_ depend or call into newtab code, please consult with the newtab team before adding an exception.

Allowed locations:

  • browser/extensions/newtab/

  • browser/components/newtab/

  • browser/modules/AboutNewTab.sys.mjs

  • browser/actors/AboutNewTabChild.sys.mjs

Examples of incorrect code for this rule:

// In toolkit/components/places/PlacesUtils.sys.mjs:
ChromeUtils.importESModule("resource://newtab/lib/TopSitesFeed.sys.mjs")

// In browser/components/urlbar/UrlbarProviderTopSites.sys.mjs:
const { ActivityStream } = ChromeUtils.importESModule("resource://newtab/lib/ActivityStream.sys.mjs")

// In browser/base/content/browser.js:
ChromeUtils.defineESModuleGetters(lazy, {
  "NewTabMessaging": "resource://newtab/lib/NewTabMessaging.sys.mjs"
})

// In browser/components/sessionstore/SessionStore.sys.mjs:
Services.wm.getMostRecentWindow("chrome://newtab/content/newtab.xhtml")

// In toolkit/modules/ResetProfile.sys.mjs:
fetch("resource://newtab/data/content/activity-stream.bundle.js")