nixos-configs/modules/home-manager/firefox/default.nix

{ pkgs, lib, ... }:
let
  firefoxAddons = import ./addons.nix pkgs lib;
  firefoxSettings = {
    "browser.aboutConfig.showWarning" = false;
    "browser.toolbars.bookmarks.visibility" = "always";
    "browser.tabs.firefox-view" = false;
    "browser.shell.checkDefaultBrowser" = false;
    "browser.translations.automaticallyPopup" = false;
    "signon.rememberSignons" = false;
    "media.webspeech.synth.dont_notify_on_error" = true;
    "browser.gesture.swipe.left" = false;
    "browser.gesture.swipe.right" = false;
    "browser.newtabpage.activity-stream.showSponsored" = false;
    "browser.newtabpage.activity-stream.showSponsoredTopSites" = false;
  };
in
{
  config = {
    programs.firefox = {
      enable = true;
      profiles = {
        default = {
          id = 0;
          isDefault = true;
          settings = firefoxSettings;
          extensions = firefoxAddons;
        };
      };
    };
  };
}