packages: Add wrapper script for nixf-tidy

Now it's possible to use this package in the ci.

packages/nixf-tidy.nix

@@ -0,0 +1,83 @@
+{
+  lib,
+  stdenvNoCC,
+  writeTextFile,
+  makeWrapper,
+  git,
+  fd,
+  jq,
+  nixf,
+}:
+
+let
+  script = writeTextFile {
+    name = "nixf-tidy";
+    text = # fish
+      ''
+        #!/usr/bin/env fish
+
+        if test "$(git rev-parse --is-inside-work-tree)" != "true"
+          echo "Not inside a git directory. Aborting."
+          exit 1
+        end
+
+        echo "⚪ Checking for issues with nixf-tidy..."
+
+        set DID_ERROR 0
+
+        for FILE in **/*.nix
+          set RESULT $(cat "$FILE" | nixf-tidy --variable-lookup)
+
+          if test "$RESULT" != "[]"
+            echo "===================================="
+            echo "❌ nixd found issues in $FILE:"
+            echo "===================================="
+            echo "$RESULT" | jq ".[] | .message, .args, .range.lCur.line"
+
+            set DID_ERROR 1
+          else
+            echo "✅ $FILE"
+          end
+        end
+
+        exit $DID_ERROR
+      '';
+  };
+in
+stdenvNoCC.mkDerivation {
+  pname = "nixf-tidy";
+  version = "0.1.0";
+
+  dontUnpack = true;
+
+  nativeBuildInputs = [
+    makeWrapper
+  ];
+
+  installPhase = ''
+    runHook preInstall
+
+    install -Dm755 ${script} $out/bin/nixf-tidy
+
+    runHook postInstall
+  '';
+
+  postInstall = ''
+    wrapProgram $out/bin/nixf-tidy \
+      --prefix PATH ":" "${lib.makeBinPath [
+        git
+        fd
+        jq
+        nixf
+      ]}"
+  '';
+
+  meta = {
+    homepage = "https://github.com/nix-community/nixd/blob/main/libnixf/README.md#nixf-tidy";
+    description = "Dedicated tool tailored for linting Nix projects";
+    license = lib.licenses.lgpl3Plus;
+    maintainers = with lib.maintainers; [ donovanglover ];
+    mainProgram = "nixf-tidy";
+    platforms = lib.platforms.linux;
+  };
+}