Merge pull request #278131 from symphorien/sane_test

  sabnzbd = handleTest ./sabnzbd.nix {};

  samba = handleTest ./samba.nix {};

  samba-wsdd = handleTest ./samba-wsdd.nix {};

  sane = handleTest ./sane.nix {};

  sanoid = handleTest ./sanoid.nix {};

  scaphandre = handleTest ./scaphandre.nix {};

  schleuder = handleTest ./schleuder.nix {};

import ./make-test-python.nix ({ pkgs, ... }:

/*

  SANE NixOS test

  ===============

  SANE is intrisically tied to hardware, so testing it is not straightforward.

  However:

  - a fake webcam can be created with v4l2loopback

  - sane has a backend (v4l) to use a webcam as a scanner

  This test creates a webcam /dev/video0, streams a still image with some text

  through this webcam, uses SANE to scan from the webcam, and uses OCR to check

  that the expected text was scanned.

*/

let

  text = "66263666188646651519653683416";

  fontsConf = pkgs.makeFontsConf {

    fontDirectories = [

      pkgs.dejavu_fonts.minimal

    ];

  };

  # an image with black on white text spelling "${text}"

  # for some reason, the test fails if it's jpg instead of png

  # the font is quite large to make OCR easier

  image = pkgs.runCommand "image.png"

    {

      # only imagemagickBig can render text

      nativeBuildInputs = [ pkgs.imagemagickBig ];

      FONTCONFIG_FILE = fontsConf;

    } ''

    magick -pointsize 100 label:${text} $out

  '';

in

{

  name = "sane";

  nodes.machine = { pkgs, config, ... }: {

    boot = {

      # create /dev/video0 as a fake webcam whose content is filled by ffmpeg

      extraModprobeConfig = ''

        options v4l2loopback devices=1 max_buffers=2 exclusive_caps=1 card_label=VirtualCam

      '';

      kernelModules = [ "v4l2loopback" ];

      extraModulePackages = [ config.boot.kernelPackages.v4l2loopback ];

    };

    systemd.services.fake-webcam = {

      wantedBy = [ "multi-user.target" ];

      description = "fill /dev/video0 with ${image}";

      /* HACK: /dev/video0 is a v4l2 only device, it misses one single v4l1

      ioctl, VIDIOCSPICT. But sane only supports v4l1, so it will log that this

      ioctl failed, and assume that the pixel format is Y8 (gray). So we tell

      ffmpeg to produce this pixel format.

      */

      serviceConfig.ExecStart = [ "${pkgs.ffmpeg}/bin/ffmpeg -framerate 30 -re -stream_loop -1 -i ${image} -f v4l2 -pix_fmt gray /dev/video0" ];

    };

    hardware.sane.enable = true;

    system.extraDependencies = [ image ];

    environment.systemPackages = [

      pkgs.fswebcam

      pkgs.tesseract

      pkgs.v4l-utils

    ];

    environment.variables.SANE_DEBUG_V4L = "128";

  };

  testScript = ''

    start_all()

    machine.wait_for_unit("fake-webcam.service")

    # the device only appears when ffmpeg starts producing frames

    machine.wait_until_succeeds("scanimage -L | grep /dev/video0")

    machine.succeed("scanimage -L >&2")

    with subtest("debugging: /dev/video0 works"):

      machine.succeed("v4l2-ctl --all >&2")

      machine.succeed("fswebcam --no-banner /tmp/webcam.jpg")

      machine.copy_from_vm("/tmp/webcam.jpg", "webcam")

    # scan with the webcam

    machine.succeed("scanimage -o /tmp/scan.png >&2")

    machine.copy_from_vm("/tmp/scan.png", "scan")

    # the image should contain "${text}"

    output = machine.succeed("tesseract /tmp/scan.png -")

    print(output)

    assert "${text}" in output, f"expected text ${text} was not found, OCR found {output!r}"

  '';

})

, avahi, libgphoto2, libieee1284, libjpeg, libpng, libtiff, libusb1, libv4l, net-snmp

, curl, systemd, libxml2, poppler, gawk

, sane-drivers

, nixosTests

# List of { src name backend } attibute sets - see installFirmware below:

, extraFirmware ? []

  # https://github.com/NixOS/nixpkgs/issues/224569

  enableParallelInstalling = false;

  passthru.tests = {

    inherit (nixosTests) sane;

  };

  meta = with lib; {

    description = "SANE (Scanner Access Now Easy) backends";

    longDescription = ''