From b31197716ed31f9bcbafdcfd1c4b5ff6fd344856 Mon Sep 17 00:00:00 2001
From: Yoann Beaugnon <yoann@beaugnon.com>
Date: Sat, 3 Feb 2024 19:08:54 +0100
Subject: [PATCH] Add treefmt-nix with nixpkgs-fmt for formatting

---
 flake.lock | 23 ++++++++++++++++++++++-
 flake.nix  | 12 +++++++++++-
 2 files changed, 33 insertions(+), 2 deletions(-)

diff --git a/flake.lock b/flake.lock
index eadee78..12a41a0 100644
--- a/flake.lock
+++ b/flake.lock
@@ -55,7 +55,28 @@
     "root": {
       "inputs": {
         "flake-parts": "flake-parts",
-        "nixpkgs": "nixpkgs"
+        "nixpkgs": "nixpkgs",
+        "treefmt-nix": "treefmt-nix"
+      }
+    },
+    "treefmt-nix": {
+      "inputs": {
+        "nixpkgs": [
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1706462057,
+        "narHash": "sha256-7dG1D4iqqt0bEbBqUWk6lZiSqqwwAO0Hd1L5opVyhNM=",
+        "owner": "numtide",
+        "repo": "treefmt-nix",
+        "rev": "c6153c2a3ff4c38d231e3ae99af29b87f1df5901",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "treefmt-nix",
+        "type": "github"
       }
     }
   },
diff --git a/flake.nix b/flake.nix
index eeb4d70..56c0a1d 100644
--- a/flake.nix
+++ b/flake.nix
@@ -4,16 +4,26 @@
   inputs = {
     nixpkgs.url = "github:NixOS/nixpkgs/nixos-23.11";
     flake-parts.url = "github:hercules-ci/flake-parts";
+    treefmt-nix.url = "github:numtide/treefmt-nix"; # Formatter
+    treefmt-nix.inputs.nixpkgs.follows = "nixpkgs";
   };
 
   outputs = inputs @ { self, nixpkgs, flake-parts, ... }:
     flake-parts.lib.mkFlake { inherit inputs; } {
+      imports = [
+        inputs.treefmt-nix.flakeModule
+      ];
 
       systems = [ "x86_64-linux" ];
 
       flake = { };
 
-      perSystem = { config, ... }: { };
+      perSystem = { config, ... }: {
+        treefmt = {
+          projectRootFile = "flake.nix";
+          programs.nixpkgs-fmt.enable = true;
+        };
+      };
     };
 
 }