sfxr-qt: add nixos test

nixos/tests/all-tests.nix

···
   seafile = handleTest ./seafile.nix {};
   searx = handleTest ./searx.nix {};
   service-runner = handleTest ./service-runner.nix {};
+  sfxr-qt = handleTest ./sfxr-qt.nix {};
   shadow = handleTest ./shadow.nix {};
   shadowsocks = handleTest ./shadowsocks {};
   shattered-pixel-dungeon = handleTest ./shattered-pixel-dungeon.nix {};

nixos/tests/sfxr-qt.nix

···
+import ./make-test-python.nix ({ pkgs, ... }: {
+  name = "sfxr-qt";
+  meta = with pkgs.lib.maintainers; {
+    maintainers = [ fgaz ];
+  };
+
+  machine = { config, pkgs, ... }: {
+    imports = [
+      ./common/x11.nix
+    ];
+
+    services.xserver.enable = true;
+    sound.enable = true;
+    environment.systemPackages = [ pkgs.sfxr-qt ];
+  };
+
+  enableOCR = true;
+
+  testScript =
+    ''
+      machine.wait_for_x()
+      # Add a dummy sound card, or the program won't start
+      machine.execute("modprobe snd-dummy")
+
+      machine.execute("sfxr-qt >&2 &")
+
+      machine.wait_for_window(r"sfxr")
+      machine.sleep(10)
+      machine.wait_for_text("requency")
+      machine.screenshot("screen")
+    '';
+})

pkgs/applications/audio/sfxr-qt/default.nix

···
 , SDL
 , python3
 , callPackage
+, nixosTests
 }:
 
 mkDerivation rec {
···
 
   passthru.tests = {
     export-square-wave = callPackage ./test-export-square-wave {};
+    sfxr-qt-starts = nixosTests.sfxr-qt;
   };
 
   meta = with lib; {