From fb515d205b694b9c1132c7a9e7e812241b9ea047 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Matej=20Jane=C5=BEi=C4=8D?= <janezic.mj@gmail.com>
Date: Fri, 20 Feb 2026 18:00:58 +0100
Subject: [PATCH] feat: switch to nixfmt and add pre-commit hook

---
 .pre-commit-config.yaml |  6 ++++++
 flake.nix               | 25 ++++++++++++++++++-------
 treefmt.toml            |  4 ----
 3 files changed, 24 insertions(+), 11 deletions(-)
 create mode 100644 .pre-commit-config.yaml
 delete mode 100644 treefmt.toml

diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
new file mode 100644
index 0000000..7a6d52b
--- /dev/null
+++ b/.pre-commit-config.yaml
@@ -0,0 +1,6 @@
+repos:
+  - repo: https://github.com/nixos/nixfmt
+    rev: v1.2.0
+    hooks:
+      - id: nixfmt-nix
+        args: [--, --check]
diff --git a/flake.nix b/flake.nix
index 2501278..cd43cbf 100644
--- a/flake.nix
+++ b/flake.nix
@@ -94,11 +94,22 @@
         lib = nixpkgs.lib;
       } { };
     }
-    // flake-utils.lib.eachDefaultSystem (system: {
-      packages = import ./packages {
-        inherit my-lib;
-        lib = nixpkgs.lib;
-      } (inputs // { inherit system; });
-      formatter = nixpkgs.legacyPackages.${system}.nixfmt-rfc-style;
-    });
+    // flake-utils.lib.eachDefaultSystem (
+      system:
+      let
+        pkgs = nixpkgs.legacyPackages.${system};
+      in
+      {
+        packages = import ./packages {
+          inherit my-lib;
+          lib = nixpkgs.lib;
+        } (inputs // { inherit system; });
+
+        formatter = pkgs.nixfmt-tree;
+
+        devShells.default = pkgs.mkShell {
+          packages = [ pkgs.pre-commit ];
+        };
+      }
+    );
 }
diff --git a/treefmt.toml b/treefmt.toml
deleted file mode 100644
index d838b92..0000000
--- a/treefmt.toml
+++ /dev/null
@@ -1,4 +0,0 @@
-[formatter.nix]
-command = "nix"
-options = ["fmt"]
-includes = [ "*.nix" ]