rofi: add "plugins" option (#2117)

* rofi: add support to plugins

* rofi: update package example

Co-authored-by: Sumner Evans <me@sumnerevans.com>

* rofi: Format package example

* rofi: Fix tests

Rofi will not try to install plugins using override when tests overlay
actual rofi package with empty scirpt

* rofi: Refactor

Co-authored-by: Sumner Evans <me@sumnerevans.com>

modules/programs/rofi.nix

@@ -207,6 +207,15 @@ in {
       '';
     };
 
+    plugins = mkOption {
+      default = [ ];
+      type = types.listOf types.package;
+      description = ''
+        List of rofi plugins to be installed.
+      '';
+      example = literalExample "[ pkgs.rofi-calc ]";
+    };
+
     width = mkOption {
       default = null;
       type = types.nullOr types.int;
@@ -405,7 +414,14 @@ in {
       inherit value;
     };
 
-    home.packages = [ cfg.package ];
+    home.packages = let
+      rofiWithPlugins = cfg.package.override
+        (old: rec { plugins = (old.plugins or [ ]) ++ cfg.plugins; });
+      rofiPackage = if builtins.hasAttr "override" cfg.package then
+        rofiWithPlugins
+      else
+        cfg.package;
+    in [ rofiPackage ];
 
     home.file."${cfg.configPath}".text = toRasi {
       configuration = ({