nix: Add linting

flake.nix

@@ -74,7 +74,7 @@
     };
 
     checks.${system} = import ./nix/checks {
-      inherit self system pkgs;
+      inherit self pkgs;
     };
   };
 }

nix/checks/default.nix

@@ -1,9 +1,9 @@
 {
   pkgs,
   self,
-  system,
 }: let
   callPackage = pkgs.lib.callPackageWith (pkgs // {inherit self;});
 in {
+  lintNix = callPackage ./lint-nix.nix {};
   openHomepage = callPackage ./open-homepage.nix {};
 }

nix/checks/lint-nix.nix

@@ -0,0 +1,27 @@
+{
+  self,
+  lib,
+  stdenv,
+  alejandra,
+  deadnix,
+  statix,
+}: let
+  inherit (lib) sourceFilesBySuffices;
+in
+  stdenv.mkDerivation {
+    dontPatch = true;
+    dontConfigure = true;
+    dontBuild = true;
+    dontInstall = true;
+    doCheck = true;
+
+    name = "lint-nix";
+    src = sourceFilesBySuffices self [".nix"];
+    checkInputs = [alejandra deadnix statix];
+    checkPhase = ''
+      mkdir -p $out
+      alejandra --check . | tee $out/alejandra.log
+      deadnix --fail | tee $out/deadnix.log
+      statix check | tee $out/statix.log
+    '';
+  }

nix/module.nix

@@ -7,7 +7,7 @@
   ...
 }: let
   inherit (lib) mkEnableOption mkIf mkOption;
-  inherit (lib.types) submodule str int;
+  inherit (lib.types) str int;
   inherit (lib.strings) escapeShellArgs;
   inherit (self.packages.${system}) server templates;