cups-pdf: add vm test

nixos/tests/all-tests.nix

@@ -151,6 +151,7 @@ in {
   coturn = handleTest ./coturn.nix {};
   couchdb = handleTest ./couchdb.nix {};
   cri-o = handleTestOn ["aarch64-linux" "x86_64-linux"] ./cri-o.nix {};
+  cups-pdf = handleTest ./cups-pdf.nix {};
   custom-ca = handleTest ./custom-ca.nix {};
   croc = handleTest ./croc.nix {};
   deluge = handleTest ./deluge.nix {};

nixos/tests/cups-pdf.nix

@@ -0,0 +1,40 @@
+import ./make-test-python.nix ({ lib, pkgs, ... }: {
+  name = "cups-pdf";
+
+  nodes.machine = { pkgs, ... }: {
+    imports = [ ./common/user-account.nix ];
+    environment.systemPackages = [ pkgs.poppler_utils ];
+    fonts.fonts = [ pkgs.dejavu_fonts ];  # yields more OCR-able pdf
+    services.printing.cups-pdf.enable = true;
+    services.printing.cups-pdf.instances = {
+      opt = {};
+      noopt.installPrinter = false;
+    };
+    hardware.printers.ensurePrinters = [{
+      name = "noopt";
+      model = "CUPS-PDF_noopt.ppd";
+      deviceUri = "cups-pdf:/noopt";
+    }];
+  };
+
+  # we cannot check the files with pdftotext, due to
+  # https://github.com/alexivkin/CUPS-PDF-to-PDF/issues/7
+  # we need `imagemagickBig` as it has ghostscript support
+
+  testScript = ''
+    from subprocess import run
+    machine.wait_for_unit("cups.service")
+    for name in ("opt", "noopt"):
+        text = f"test text {name}".upper()
+        machine.wait_until_succeeds(f"lpstat -v {name}")
+        machine.succeed(f"su - alice -c 'echo -e \"\n  {text}\" | lp -d {name}'")
+        # wait until the pdf files are completely produced and readable by alice
+        machine.wait_until_succeeds(f"su - alice -c 'pdfinfo /var/spool/cups-pdf-{name}/users/alice/*.pdf'")
+        machine.succeed(f"cp /var/spool/cups-pdf-{name}/users/alice/*.pdf /tmp/{name}.pdf")
+        machine.copy_from_vm(f"/tmp/{name}.pdf", "")
+        run(f"${pkgs.imagemagickBig}/bin/convert -density 300 $out/{name}.pdf $out/{name}.jpeg", shell=True, check=True)
+        assert text.encode() in run(f"${lib.getExe pkgs.tesseract} $out/{name}.jpeg stdout", shell=True, check=True, capture_output=True).stdout
+  '';
+
+  meta.maintainers = [ lib.maintainers.yarny ];
+})

pkgs/misc/cups/drivers/cups-pdf-to-pdf/default.nix

@@ -3,6 +3,7 @@
 , fetchFromGitHub
 , cups
 , coreutils
+, nixosTests
 }:
 
 stdenv.mkDerivation rec {
@@ -40,6 +41,8 @@ stdenv.mkDerivation rec {
     runHook postInstall
   '';
 
+  passthru.tests.vmtest = nixosTests.cups-pdf;
+
   meta = with lib; {
     description = "A CUPS backend that turns print jobs into searchable PDF files";
     homepage = "https://github.com/alexivkin/CUPS-PDF-to-PDF";