qrcode: apply guideline checklist

Signed-off-by: lucasew <lucas59356@gmail.com>
Assisted-by: Grok (xAI) via grok-cli

pkgs/by-name/qr/qrcode/package.nix

@@ -3,9 +3,10 @@
   stdenv,
   fetchFromGitHub,
   unstableGitUpdater,
+  testers,
 }:
 
-stdenv.mkDerivation {
+stdenv.mkDerivation (finalAttrs: {
   pname = "qrcode";
   version = "0-unstable-2025-04-29";
 
@@ -16,25 +17,38 @@ stdenv.mkDerivation {
     hash = "sha256-WQeZB8G9Nm68mYmLr0ksZdFDcQxF54X0yJxigJZWvMo=";
   };
 
+  strictDeps = true;
+  enableParallelBuilding = true;
+
   makeFlags = [ "CC=${stdenv.cc.targetPrefix}cc" ];
 
+  # Upstream Makefile has no install target.
   installPhase = ''
-    mkdir -p "$out"/{bin,share/doc/qrcode}
-    cp qrcode "$out/bin"
-    cp DOCUMENTATION LICENCE "$out/share/doc/qrcode"
+    runHook preInstall
+    install -Dm755 qrcode -t "$out/bin"
+    install -Dm644 DOCUMENTATION LICENCE -t "$out/share/doc/qrcode"
+    runHook postInstall
   '';
 
-  passthru.updateScript = unstableGitUpdater { };
+  passthru = {
+    updateScript = unstableGitUpdater { };
+    tests.version = testers.testVersion {
+      package = finalAttrs.finalPackage;
+      # Upstream exits non-zero even on successful -V.
+      command = "{ qrcode -V || true; }";
+      version = "0.1";
+    };
+  };
 
   meta = {
-    description = "Small QR-code tool";
+    description = "QR-code encoder and decoder";
     homepage = "https://github.com/qsantos/qrcode";
     license = lib.licenses.gpl3Plus;
     maintainers = with lib.maintainers; [
       raskin
       lucasew
     ];
-    platforms = with lib.platforms; unix;
+    platforms = lib.platforms.unix;
     mainProgram = "qrcode";
   };
-}
+})