polybar: don't generate config if no options are set (#3383)

* polybar: don't generate config if no options are set

* polybar: add h7x4 as maintainer

.github/CODEOWNERS

@@ -263,6 +263,9 @@ Makefile                                              @thiagokokada
 /modules/programs/pls.nix                             @arjan-s
 /tests/modules/programs/pls                           @arjan-s
 
+/modules/programs/polybar.nix                         @h7x4
+/tests/modules/programs/polybar                       @h7x4
+
 /modules/programs/powerline-go.nix                    @DamienCassou
 
 /modules/programs/pubs.nix                            @loicreynier

modules/services/polybar.nix

@@ -1,10 +1,11 @@
-{ config, lib, pkgs, ... }:
+{ config, options, lib, pkgs, ... }:
 
 with lib;
 
 let
 
   cfg = config.services.polybar;
+  opt = options.services.polybar;
 
   eitherStrBoolIntList = with types;
     either str (either bool (either int (listOf str)));
@@ -198,15 +199,19 @@ in {
         lib.platforms.linux)
     ];
 
+    meta.maintainers = with maintainers; [ h7x4 ];
+
     home.packages = [ cfg.package ];
-    xdg.configFile."polybar/config.ini".source = configFile;
+    xdg.configFile."polybar/config.ini" = let
+      isDeclarativeConfig = cfg.settings != opt.settings.default || cfg.config
+        != opt.config.default || cfg.extraConfig != opt.extraConfig.default;
+    in mkIf isDeclarativeConfig { source = configFile; };
 
     systemd.user.services.polybar = {
       Unit = {
         Description = "Polybar status bar";
         PartOf = [ "tray.target" ];
-        X-Restart-Triggers =
-          [ "${config.xdg.configFile."polybar/config.ini".source}" ];
+        X-Restart-Triggers = [ "${config.xdg.configHome}/polybar/config.ini" ];
       };
 
       Service = {

tests/modules/services/polybar/basic-configuration.nix

@@ -47,7 +47,7 @@
       serviceFile=home-files/.config/systemd/user/polybar.service
 
       assertFileExists $serviceFile
-      assertFileRegex $serviceFile 'X-Restart-Triggers=.*polybar\.conf'
+      assertFileRegex $serviceFile 'X-Restart-Triggers=.*/.config/polybar/config.ini'
       assertFileRegex $serviceFile 'ExecStart=.*/bin/polybar-start'
 
       assertFileExists home-files/.config/polybar/config.ini

tests/modules/services/polybar/default.nix

@@ -1 +1,4 @@
-{ polybar-basic-configuration = ./basic-configuration.nix; }
+{
+  polybar-basic-configuration = ./basic-configuration.nix;
+  polybar-empty-configuration = ./empty-configuration.nix;
+}

tests/modules/services/polybar/empty-configuration.nix

@@ -0,0 +1,21 @@
+{ config, pkgs, ... }:
+
+{
+  config = {
+    services.polybar = {
+      enable = true;
+      package = config.lib.test.mkStubPackage { };
+      script = "polybar bar &";
+    };
+
+    nmt.script = ''
+      serviceFile=home-files/.config/systemd/user/polybar.service
+
+      assertFileExists $serviceFile
+      assertFileRegex $serviceFile 'X-Restart-Triggers=.*/.config/polybar/config.ini'
+      assertFileRegex $serviceFile 'ExecStart=.*/bin/polybar-start'
+
+      assertPathNotExists home-files/.config/polybar/config.ini
+    '';
+  };
+}