nixos/auto-cpufreq: init vm test (#350507)

nixos/tests/all-tests.nix

···
   audiobookshelf = handleTest ./audiobookshelf.nix {};
   auth-mysql = handleTest ./auth-mysql.nix {};
   authelia = handleTest ./authelia.nix {};
+  auto-cpufreq = handleTest ./auto-cpufreq.nix {};
   avahi = handleTest ./avahi.nix {};
   avahi-with-resolved = handleTest ./avahi.nix { networkd = true; };
   ayatana-indicators = runTest ./ayatana-indicators.nix;

nixos/tests/auto-cpufreq.nix

···
+import ./make-test-python.nix (
+  { pkgs, ... }:
+
+  {
+    name = "auto-cpufreq-server";
+
+    nodes = {
+      machine =
+        { pkgs, ... }:
+        {
+          # service will still start but since vm inside qemu cpufreq adjustments
+          # cannot be made. This will resource in the following error but the service
+          # remains up:
+          #   ERROR:
+          #   Couldn't find any of the necessary scaling governors.
+          services.auto-cpufreq = {
+            enable = true;
+            settings = {
+              charger = {
+                turbo = "auto";
+              };
+            };
+          };
+        };
+    };
+
+    testScript = ''
+      machine.start()
+      machine.wait_for_unit("auto-cpufreq.service")
+      machine.succeed("auto-cpufreq --force reset")
+    '';
+  }
+)

pkgs/by-name/au/auto-cpufreq/package.nix

···
   wrapGAppsHook3,
   gtk3,
   getent,
+  nixosTests,
 }:
 python3Packages.buildPythonPackage rec {
   pname = "auto-cpufreq";
···
     mkdir -p $out/share/polkit-1/actions
     cp scripts/org.auto-cpufreq.pkexec.policy $out/share/polkit-1/actions
   '';
+
+  passthru.tests = {
+    inherit (nixosTests) auto-cpufreq;
+  };
 
   meta = {
     mainProgram = "auto-cpufreq";