htop: let htop program use its default settings

Don't generate the `htoprc` when using default settings to use the defaults of
the htop program.

Rename the test for this case to 'empty-settings'.

modules/programs/htop.nix

@@ -96,55 +96,7 @@ in {
 
     settings = mkOption {
       type = types.attrs;
-      default = {
-        account_guest_in_cpu_meter = false;
-        color_scheme = 0;
-        cpu_count_from_zero = false;
-        delay = 15;
-        detailed_cpu_time = false;
-        enable_mouse = true;
-        fields = with fields; [
-          PID
-          USER
-          PRIORITY
-          NICE
-          M_SIZE
-          M_RESIDENT
-          M_SHARE
-          STATE
-          PERCENT_CPU
-          PERCENT_MEM
-          TIME
-          COMM
-        ];
-        header_margin = true;
-        hide_kernel_threads = true;
-        hide_threads = false;
-        hide_userland_threads = false;
-        highlight_base_name = false;
-        highlight_megabytes = true;
-        highlight_threads = true;
-        shadow_other_users = false;
-        show_cpu_frequency = false;
-        show_cpu_usage = false;
-        show_program_path = true;
-        show_thread_names = false;
-        sort_direction = 1;
-        sort_key = fields.PERCENT_CPU;
-        tree_view = false;
-        update_process_names = false;
-        vim_mode = false;
-      } // (leftMeters [
-        (bar "AllCPUs2")
-        (bar "Memory")
-        (bar "Swap")
-        (text "Zram")
-      ]) // (rightMeters [
-        (text "Tasks")
-        (text "LoadAverage")
-        (text "Uptime")
-        (text "Systemd")
-      ]);
+      default = { };
       example = literalExample ''
         {
           color_scheme = 6;
@@ -193,7 +145,8 @@ in {
 
     home.packages = [ pkgs.htop ];
 
-    xdg.configFile."htop/htoprc".text =
-      concatStringsSep "\n" (mapAttrsToList formatOption cfg.settings);
+    xdg.configFile."htop/htoprc" = mkIf (cfg.settings != { }) {
+      text = concatStringsSep "\n" (mapAttrsToList formatOption cfg.settings);
+    };
   };
 }

tests/modules/programs/htop/default.nix

@@ -1,4 +1,4 @@
 {
-  htop-default-settings = ./default-settings.nix;
+  htop-empty-settings = ./empty-settings.nix;
   htop-example-settings = ./example-settings.nix;
 }

tests/modules/programs/htop/empty-settings.nix

@@ -7,7 +7,7 @@ with lib;
     programs.htop.enable = true;
 
     nmt.script = ''
-      assertFileExists home-files/.config/htop/htoprc
+      assertPathNotExists home-files/.config/htop
     '';
   };
 }