add treefmt-nix

flake.lock

@@ -695,7 +695,7 @@
     },
     "nim2nix_3": {
       "inputs": {
-        "nixpkgs": "nixpkgs_5"
+        "nixpkgs": "nixpkgs_6"
       },
       "locked": {
         "lastModified": 1725469705,
@@ -894,6 +894,22 @@
       }
     },
     "nixpkgs_5": {
+      "locked": {
+        "lastModified": 1735554305,
+        "narHash": "sha256-zExSA1i/b+1NMRhGGLtNfFGXgLtgo+dcuzHzaWA6w3Q=",
+        "owner": "nixos",
+        "repo": "nixpkgs",
+        "rev": "0e82ab234249d8eee3e8c91437802b32c74bb3fd",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nixos",
+        "ref": "nixpkgs-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "nixpkgs_6": {
       "locked": {
         "lastModified": 1724479785,
         "narHash": "sha256-pP3Azj5d6M5nmG68Fu4JqZmdGt4S4vqI5f8te+E/FTw=",
@@ -971,6 +987,7 @@
         "pixi": "pixi",
         "sops-nix": "sops-nix",
         "stable": "stable",
+        "treefmt-nix": "treefmt-nix_2",
         "tsm": "tsm",
         "utils": "utils"
       }
@@ -1129,6 +1146,24 @@
         "type": "github"
       }
     },
+    "treefmt-nix_2": {
+      "inputs": {
+        "nixpkgs": "nixpkgs_5"
+      },
+      "locked": {
+        "lastModified": 1736154270,
+        "narHash": "sha256-p2r8xhQZ3TYIEKBoiEhllKWQqWNJNoT9v64Vmg4q8Zw=",
+        "owner": "numtide",
+        "repo": "treefmt-nix",
+        "rev": "13c913f5deb3a5c08bb810efd89dc8cb24dd968b",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "treefmt-nix",
+        "type": "github"
+      }
+    },
     "tsm": {
       "inputs": {
         "nim2nix": "nim2nix_3",

flake.nix

@@ -7,6 +7,7 @@
     nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
     stable.url = "github:nixos/nixpkgs/nixos-24.05";
     my-nixpkgs.url = "github:daylinmorgan/nixpkgs/nixos-unstable";
+    treefmt-nix.url = "github:numtide/treefmt-nix";
 
     nixpkgs-wayland.url = "github:nix-community/nixpkgs-wayland";
     nixos-wsl.url = "github:nix-community/NixOS-WSL";

lib/default.nix

@@ -1,4 +1,9 @@
-inputs@{ nixpkgs, self, ... }:
+inputs@{
+  nixpkgs,
+  treefmt-nix,
+  self,
+  ...
+}:
 let
   lib = nixpkgs.lib.extend (import ./extended.nix inputs);
 
@@ -7,6 +12,9 @@ let
     genAttrs
     pkgFromSystem
     loadOverlays
+    enabled
+    listify
+    enableAttrs
     ;
 
   inherit (import ./find-modules.nix { inherit lib; }) findModulesList;
@@ -51,7 +59,7 @@ let
         default = oizys;
         oizys = pkgs.callPackage ../pkgs/oizys { };
         iso = mkIso.config.system.build.isoImage;
-        lix = pkgs.lix;
+        lix = pkgFromSystem pkgs.system "lix-module";
       }
       // (inheritFlakePkgs pkgs [
         "pixi"
@@ -77,7 +85,24 @@ let
         system = pkgs.system;
       }
     );
-    formatter = forAllSystems (pkgs: pkgs.nixfmt-rfc-style);
+    # formatter = forAllSystems (pkgs: pkgs.nixfmt-rfc-style);
+    formatter = forAllSystems (
+      pkgs:
+      (treefmt-nix.lib.evalModule pkgs (
+        { ... }:
+        {
+          projectRootFile = "flake.nix";
+          # don't warn me about missing formatters
+          settings.excludes = [
+            # likely to be nnl lockfiles
+            "pkgs/**/lock.json"
+            "hosts/**/secrets.yaml"
+          ];
+          settings.on-unmatched = "debug";
+          programs = "prettier|nixfmt" |> listify |> enableAttrs;
+        }
+      )).config.build.wrapper
+    );
   };
 in
 {