pasystray: add extraOptions

Allows a user to, for example, add the `-g` option.

Also add a basic test case.

tests/default.nix

@@ -223,6 +223,7 @@ import nmt {
     ./modules/services/pantalaimon
     ./modules/services/parcellite
     ./modules/services/pass-secret-service
+    ./modules/services/pasystray
     ./modules/services/pbgopy
     ./modules/services/picom
     ./modules/services/playerctld

tests/modules/services/pasystray/default.nix

@@ -0,0 +1 @@
+{ pasystray-service = ./service.nix; }

tests/modules/services/pasystray/expected.service

@@ -0,0 +1,13 @@
+[Install]
+WantedBy=graphical-session.target
+
+[Service]
+Environment=PATH=@paprefs@/bin:@pavucontrol@/bin
+ExecStart='@pasystray@/bin/pasystray' '-g'
+
+[Unit]
+After=graphical-session-pre.target
+After=tray.target
+Description=PulseAudio system tray
+PartOf=graphical-session.target
+Requires=tray.target

tests/modules/services/pasystray/service.nix

@@ -0,0 +1,19 @@
+{ ... }:
+
+{
+  services.pasystray = {
+    enable = true;
+    extraOptions = [ "-g" ];
+  };
+
+  test.stubs = {
+    pasystray = { };
+    paprefs = { };
+    pavucontrol = { };
+  };
+
+  nmt.script = ''
+    serviceFile=$(normalizeStorePaths home-files/.config/systemd/user/pasystray.service)
+    assertFileContent "$serviceFile" ${./expected.service}
+  '';
+}