chore: fix formatting and add treefmt

.envrc

@@ -1,3 +1,5 @@
+#!/bin/sh
+
 watch_file devshell.nix
 
 use flake

.github/workflows/nix-flake-check.yml

@@ -1,10 +1,8 @@
 name: Continuous Integration
-
 on:
   pull_request:
   push:
     branches: [main]
-
 jobs:
   checks:
     name: "Checks"

.github/workflows/nix-flake-update.yml

@@ -3,7 +3,6 @@ on:
   workflow_dispatch: # allows manual triggering
   schedule:
     - cron: '0 0 * * 0' # runs weekly on Sunday at 00:00
-
 jobs:
   lockfile:
     runs-on: ubuntu-latest

devshell.nix

@@ -24,7 +24,7 @@
       name = "format";
       help = "Format the project";
       command = ''
-        nixpkgs-fmt .
+        treefmt .
       '';
       category = "dev";
     }

nixos/configurations.nix

@@ -21,8 +21,7 @@ let
     nixpkgs.lib.nixosSystem {
       inherit system;
 
-      modules =
-        [
+      modules = [
         {
           nixpkgs.overlays = nixpkgs.lib.attrValues self.overlays;
         }

nixos/stolas/default.nix

@@ -1,4 +1,9 @@
-{ config, lib, pkgs, ... }:
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
 {
 
   imports = [

outputs.nix

@@ -5,12 +5,14 @@
   nixpkgs,
   agenix,
   devshell,
+  treefmt-nix,
   ...
 }@inputs:
 (flake-utils.lib.eachDefaultSystem (
   system:
   let
     pkgs = import nixpkgs { inherit system; };
+    treefmtEval = treefmt-nix.lib.evalModule pkgs ./treefmt.nix;
   in
   {
     devShells.default =
@@ -26,7 +28,7 @@
       in
       import ./devshell.nix { inherit pkgs extraModules; };
 
-    formatter = pkgs.nixfmt-tree;
+    formatter = treefmtEval.config.build.wrapper;
 
     packages = import ./pkgs { inherit pkgs; } // {
       installer-iso = self.nixosConfigurations.installer.config.system.build.isoImage;
@@ -34,7 +36,6 @@
   }
 ))
 // {
-
   hmModules = import ./home/modules.nix { lib = nixpkgs.lib; };
 
   nixosConfigurations = import ./nixos/configurations.nix inputs;

pkgs/default.nix

@@ -1,3 +1,4 @@
-{ pkgs }: {
+{ pkgs }:
+{
   citizen-cups = pkgs.callPackage ./citizen-cups.nix { };
 }

treefmt.nix

@@ -0,0 +1,8 @@
+{ pkgs, ... }:
+{
+  projectRootFile = "flake.nix";
+  programs.nixfmt.enable = true;
+  programs.shellcheck.enable = pkgs.hostPlatform.system != "riscv64-linux";
+  programs.shfmt.enable = pkgs.hostPlatform.system != "riscv64-linux";
+  programs.yamlfmt.enable = true;
+}