create dummy serial ports for the systemd service

nix/module.nix

@@ -12,7 +12,7 @@ in {
     enable = mkEnableOption "pi-air-quality-monitor";
     package = mkOption {
       type = types.package;
-      default = self.packages.${pkgs.system}.pi-air-quality-monitor;
+      default = self.packages.${pkgs.system}.air-quality-monitor;
     };
 
     openFirewall = mkOption {

nix/packages/air-quality-monitor.nix

@@ -0,0 +1,63 @@
+{
+  self,
+  lib,
+  python3Packages,
+  makeWrapper,
+  python3,
+  ...
+}: let
+  pname = "pi_air_quality_monitor";
+  version = "0.0.1";
+in
+  python3Packages.buildPythonApplication {
+    inherit pname version;
+    format = "other";
+
+    src = self + /src;
+
+    pythonPath = with python3Packages; [
+      pyserial
+      flask
+      redis
+      ipython
+      apscheduler
+      flask-cors
+      (
+        buildPythonPackage rec {
+          pname = "python-aqi";
+          version = "0.6.1";
+          src = fetchPypi {
+            inherit pname version;
+            hash = "sha256-FBoDoP7UiIDchwbKV7A/MPqRq2DpMwR0v5yaj7m5YCA=";
+          };
+        }
+      )
+    ];
+
+    nativeBuildInputs = [makeWrapper];
+    installFlags = ["prefix=$(out/bin)"];
+
+    postUnpack = ''
+      mkdir -p $out/bin
+      cp -rvf $src/* $out
+    '';
+
+    preFixup = ''
+      buildPythonPath "$pythonPath"
+      gappsWrapperArgs+=(
+        --prefix PYTHONPATH : "$program_PYTHONPATH"
+      )
+      makeWrapper ${lib.getExe python3} $out/bin/${pname} \
+          --add-flags $out/app.py \
+          --prefix PYTHONPATH : "$program_PYTHONPATH" \
+          --chdir $out/bin
+    '';
+
+    meta = {
+      description = "An air quality monitoring service with a Raspberry Pi and a SDS011 sensor. ";
+      homepage = "https://github.com/rydercalmdown/pi_air_quality_monitor";
+      mainProgram = pname;
+      platforms = ["aarch64-linux" "x86_64-linux"];
+      maintainers = with lib.maintainers; [NotAShelf];
+    };
+  }

nix/packages/dummy-serial.nix

@@ -0,0 +1,30 @@
+{
+  stdenv,
+  fetchFromGitHub,
+  ...
+}:
+stdenv.mkDerivation {
+  pname = "dummy-serial";
+  version = "0.1.0";
+
+  src = fetchFromGitHub {
+    owner = "notashelf";
+    repo = "dummy-serial";
+    rev = "v0.1.0";
+    hash = "sha256-+zXA5Ko8ikgkmkm1eyx2VMQQjp61osSpq4K+d9WEqq8=";
+  };
+
+  makeFlags = ["TARGET=main"];
+
+  installPhase = ''
+    runHook preInstall
+    mkdir -p $out/bin
+    cp -rvf main $out/bin/dummy-serial
+    runHook postInstall
+  '';
+
+  meta = {
+    description = "Create dummy serial ports through PseudoTTYs";
+    mainProgram = "dummy-serial";
+  };
+}

nix/tests/checks/basic.nix

@@ -1,9 +1,11 @@
 {
   nixosTest,
   self,
+  self',
+  lib,
   ...
 }: let
-  serialPort = "/dev/ttyS0";
+  serialPort = "/dev/pts/2";
 in
   nixosTest {
     name = "basic";
@@ -50,24 +52,25 @@ in
     testScript = ''
       server.start()
 
-      server.wait_for_unit("default.target")
+      server.wait_for_unit("network.target")
       log.info("Checking if configured serial port exists")
-      server.succeed("ls -lah ${serialPort}")
+      serialPort = server.succeed("${lib.getExe self'.packages.dummy-serial} --quiet")
+
+      if any(serialPort):
+        log.info("Serial port exists!")
+      else:
+        log.info("Serial port does not exist")
 
       log.info("Check if unit is running correctly")
       server.wait_for_unit("pi-air-quality-monitor.service")
-      server.succeed("systemctl status pi-air-quality-monitor.service | grep 'Active: active (running)' >&2")
-      server.fail("journalctl -u pi-air-quality-monitor.service | grep 'RuntimeError'")
-
-      log.info("Showing units content")
-      server.succeed("systemctl status pi-air-quality-monitor.service >&2")
-      server.succeed("systemctl cat pi-air-quality-monitor.service >&2")
+      server.succeed("systemctl status pi-air-quality-monitor.service | grep 'Active: active (running)'")
+      server.fail("journalctl -xeu pi-air-quality-monitor.service | grep 'RuntimeError'")
 
       log.info("Checking if service is accessible locally")
-      server.succeed("nc -vz localhost 8080")
+      server.succeed("curl --fail http://localhost:8080 | grep 'Air'")
 
       client.start()
-      client.wait_for_unit("default.target")
+      client.wait_for_unit("network.target")
       client.succeed("nc -vz server 8080")
     '';
   }

nix/tests/default.nix

@@ -19,7 +19,7 @@
     packages.test = self'.checks.basic.driverInteractive;
 
     checks = {
-      basic = callPackage ./checks/basic.nix {inherit self;};
+      basic = callPackage ./checks/basic.nix {inherit self self';};
       default = self'.checks.basic;
     };
   };