fix: Add formatter

.envrc

@@ -0,0 +1,2 @@
+# shellcheck shell=bash
+use nix

by-name/sz3/default.nix

@@ -24,8 +24,7 @@ stdenv.mkDerivation {
     pkg-config
   ];
 
-  buildInputs =
-    [
+  buildInputs = [
     zstd
     gsl
   ]

npins/sources.json

@@ -5,6 +5,19 @@
       "name": "nixos-unstable",
       "url": "https://releases.nixos.org/nixos/unstable/nixos-26.05pre1004030.64c08a7ca051/nixexprs.tar.xz",
       "hash": "sha256-NpH8iEQ5JHv/BtUuzTEXUMDxPLetCDzIv4OxL8H7Kps="
+    },
+    "treefmt-nix": {
+      "type": "Git",
+      "repository": {
+        "type": "GitHub",
+        "owner": "numtide",
+        "repo": "treefmt-nix"
+      },
+      "branch": "main",
+      "submodules": false,
+      "revision": "db947814a175b7ca6ded66e21383d938df01c227",
+      "url": "https://github.com/numtide/treefmt-nix/archive/db947814a175b7ca6ded66e21383d938df01c227.tar.gz",
+      "hash": "sha256-eynAfOmbmxJnkp7YewvCEbShNnnYJ9gLLqkzsYtBPeM="
     }
   },
   "version": 7

shell.nix

@@ -2,12 +2,14 @@
   sources ? import ./npins,
   pkgs ? import sources.nixpkgs { },
 }:
-
+let
+  treefmt = pkgs.callPackage ./tools/treefmt.nix { inherit sources; };
+in
 pkgs.mkShellNoCC {
   packages = [
     pkgs.npins
     pkgs.nix-init
-    pkgs.nixfmt-rfc-style
     pkgs.nix-update
+    treefmt
   ];
 }

tools/treefmt.nix

@@ -0,0 +1,22 @@
+{ pkgs, sources, ... }:
+let
+  treefmt-nix = import sources.treefmt-nix;
+in
+treefmt-nix.mkWrapper pkgs {
+  projectRootFile = ".git/config";
+  programs = {
+    nixfmt.enable = true;
+    deadnix.enable = true;
+    statix = {
+      enable = true;
+      disabled-lints = [
+        "manual_inherit_from"
+        "repeated_keys"
+      ];
+    };
+    shellcheck.enable = true;
+  };
+  settings.global.excludes = [
+    "npins/default.nix"
+  ];
+}