add treefmt

flake.lock

@@ -68,10 +68,28 @@
         "type": "github"
       }
     },
+    "nixpkgs_3": {
+      "locked": {
+        "lastModified": 1745377448,
+        "narHash": "sha256-jhZDfXVKdD7TSEGgzFJQvEEZ2K65UMiqW5YJ2aIqxMA=",
+        "owner": "nixos",
+        "repo": "nixpkgs",
+        "rev": "507b63021ada5fee621b6ca371c4fca9ca46f52c",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nixos",
+        "ref": "nixpkgs-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
     "root": {
       "inputs": {
         "deploy-rs": "deploy-rs",
-        "nixpkgs": "nixpkgs_2"
+        "nixpkgs": "nixpkgs_2",
+        "systems": "systems_2",
+        "treefmt-nix": "treefmt-nix"
       }
     },
     "systems": {
@@ -89,6 +107,38 @@
         "type": "github"
       }
     },
+    "systems_2": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "id": "systems",
+        "type": "indirect"
+      }
+    },
+    "treefmt-nix": {
+      "inputs": {
+        "nixpkgs": "nixpkgs_3"
+      },
+      "locked": {
+        "lastModified": 1746216483,
+        "narHash": "sha256-4h3s1L/kKqt3gMDcVfN8/4v2jqHrgLIe4qok4ApH5x4=",
+        "owner": "numtide",
+        "repo": "treefmt-nix",
+        "rev": "29ec5026372e0dec56f890e50dbe4f45930320fd",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "treefmt-nix",
+        "type": "github"
+      }
+    },
     "utils": {
       "inputs": {
         "systems": "systems"

flake.nix

@@ -3,17 +3,15 @@
   inputs = {
     nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
 		deploy-rs.url = "github:serokell/deploy-rs";
+    treefmt-nix.url = "github:numtide/treefmt-nix";
 	};
 
-	outputs = { self, nixpkgs, deploy-rs }: let
-		systems = [ "x86_64-linux" "aarch64-linux" "aarch64-darwin" "x86_64-darwin" ];
-		forAllSystems = function:
-			nixpkgs.lib.genAttrs systems (system: function (
-				import nixpkgs {
-					inherit system;
-					config.allowUnfree = true;
-				}
-			));
+	outputs = { self, nixpkgs, deploy-rs, systems, treefmt-nix }: let
+		# systems = [ "x86_64-linux" "aarch64-linux" "aarch64-darwin" "x86_64-darwin" ];
+		forAllSystems = fn:
+			nixpkgs.lib.genAttrs (import systems) (system: fn nixpkgs.legacyPackages.${system});
+
+    treefmtEval = forAllSystems (pkgs: treefmt-nix.lib.evalModule pkgs ./treefmt.nix);
 
 	in {
 		apps = forAllSystems (pkgs: {
@@ -44,6 +42,12 @@
 			};
 		};
 
+    formatter = forAllSystems (pkgs: treefmtEval.${pkgs.system}.config.build.wrapper);
+
+    checks = forAllSystems (pkgs: {
+      formatting = treefmtEval.${pkgs.system}.config.build.check self;
+    });
+
 		devShells = forAllSystems (pkgs: {
 			default = pkgs.mkShell {
 				packages = with pkgs; [

treefmt.nix

@@ -0,0 +1,6 @@
+{ pkgs, ... }:
+{
+  projectRootFile = "flake.nix";
+  programs.nixfmt.enable = true;
+  programs.prettier.enable = true;
+}