swaync: add module

Co-authored-by: Ryan Horiguchi <rhoriguchi@users.noreply.github.com>

tests/default.nix

@@ -260,6 +260,7 @@ in import nmtSrc {
     ./modules/services/screen-locker
     ./modules/services/signaturepdf
     ./modules/services/swayidle
+    ./modules/services/swaync
     ./modules/services/swayosd
     ./modules/services/sxhkd
     ./modules/services/syncthing/linux

tests/modules/services/swaync/default.nix

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

tests/modules/services/swaync/swaync.nix

@@ -0,0 +1,35 @@
+{ config, ... }:
+
+{
+  services.swaync = {
+    enable = true;
+    package = config.lib.test.mkStubPackage {
+      name = "swaync";
+      outPath = "@swaync@";
+    };
+  };
+
+  nmt.script = ''
+    assertFileContent \
+      home-files/.config/systemd/user/swaync.service \
+      ${
+        builtins.toFile "swaync.service" ''
+          [Install]
+          WantedBy=graphical-session.target
+
+          [Service]
+          BusName=org.freedesktop.Notifications
+          ExecStart=@swaync@/bin/swaync
+          Restart=on-failure
+          Type=dbus
+
+          [Unit]
+          After=graphical-session-pre.target
+          ConditionEnvironment=WAYLAND_DISPLAY
+          Description=Swaync notification daemon
+          Documentation=https://github.com/ErikReider/SwayNotificationCenter
+          PartOf=graphical-session.target
+        ''
+      }
+  '';
+}