Clean up and update flake

flake.nix

@@ -3,6 +3,7 @@
 
   inputs = {
     nixpkgs.url = "github:nixos/nixpkgs/nixos-22.05";
+    nix-filter.url = "github:numtide/nix-filter";
     npmlock2nix = {
       url = "github:nix-community/npmlock2nix";
       flake = false;
@@ -12,7 +13,7 @@
   outputs = {
     self,
     nixpkgs,
-    flake-utils,
+    nix-filter,
     npmlock2nix,
   }: let
     # At the moment, we only deploy to x86_64-linux. Update when we
@@ -27,7 +28,11 @@
   in {
     packages.${system} = rec {
       tlaternet-templates = pkgs.npmlock2nix.build {
-        src = self;
+        src = pkgs.lib.cleanSource self;
+
+        buildInputs = with pkgs; [
+          util-linux
+        ];
 
         installPhase = ''
           cp -r dist $out/
@@ -35,8 +40,6 @@
 
         node_modules_attrs = {
           buildInputs = with pkgs; [
-            elmPackages.elm
-
             pkg-config
             python3
             vips
@@ -50,11 +53,21 @@
 
     devShells.${system} = {
       default = pkgs.npmlock2nix.shell {
-        src = self;
+        src = nix-filter.lib {
+          root = self;
+          include = [
+            "package.json"
+            "package-lock.json"
+          ];
+        };
+
+        buildInputs = with pkgs.nodePackages; [
+          npm-check-updates
+          prettier
+        ];
+
         node_modules_attrs = {
           buildInputs = with pkgs; [
-            elmPackages.elm
-
             pkg-config
             python3
             vips