kanshi: Add test to check service when settings are unset

tests/modules/services/kanshi/default.nix

@@ -4,4 +4,5 @@ lib.optionalAttrs pkgs.stdenv.hostPlatform.isLinux {
   kanshi-basic-configuration = ./basic-configuration.nix;
   kanshi-new-configuration = ./new-configuration.nix;
   kanshi-alias-assertion = ./alias-assertion.nix;
+  kanshi-empty-settings = ./empty-settings.nix;
 }

tests/modules/services/kanshi/empty-settings.nix

@@ -0,0 +1,18 @@
+{ config, ... }:
+{
+  config = {
+    services.kanshi = {
+      enable = true;
+      package = config.lib.test.mkStubPackage { };
+    };
+
+    nmt.script = ''
+      serviceFile=home-files/.config/systemd/user/kanshi.service
+
+      assertFileExists $serviceFile
+      assertFileContent \
+        $(normalizeStorePaths $serviceFile) \
+        ${./empty-settings.service}
+    '';
+  };
+}

tests/modules/services/kanshi/empty-settings.service

@@ -0,0 +1,16 @@
+[Install]
+WantedBy=graphical-session.target
+
+[Service]
+ExecReload=/nix/store/00000000000000000000000000000000-dummy/bin/kanshictl reload
+ExecStart=/nix/store/00000000000000000000000000000000-dummy/bin/kanshi
+Restart=always
+Type=simple
+
+[Unit]
+After=graphical-session.target
+ConditionEnvironment=WAYLAND_DISPLAY
+Description=Dynamic output configuration
+Documentation=man:kanshi(1)
+PartOf=graphical-session.target
+Requires=graphical-session.target