Expanded justfile to cover testing and updates

justfile

@@ -6,6 +6,7 @@ default:
 
 rebuild:
   #!/usr/bin/env bash
+  set -euxo pipefail
   HOSTNAME=$(hostname)
   if [ $HOSTNAME == "alastor" ]; then
     nh os switch . -- -vv --impure -j 4;
@@ -13,9 +14,9 @@ rebuild:
   fi
   nh os switch . -- -vv;
 
-
 beleth:
   #!/usr/bin/env bash
+  set -euxo pipefail
   arch=$(nix-instantiate --eval -E 'builtins.currentSystem')
   arch_sanitized=$(echo $arch | sed 's/^"//;s/"$//')
   if [ $arch_sanitized == "x86_64-linux" ]; then
@@ -24,3 +25,27 @@ beleth:
     exit
   fi
   @echo "Host arch needs to be 'x86_64-linux'! Aborting...";
+
+update:
+  nix flake update
+
+test target="":
+  #!/usr/bin/env bash 
+  set -euo pipefail
+  target={{target}}
+  configurations=$(nix flake show --json --all-systems --quiet | nix run nixpkgs#jq -- -r '.nixosConfigurations | keys[]')
+
+  if [ "$target" == "" ]; then
+    nix flake check;
+    exit
+  fi
+
+  for config in $configurations; do
+    if [ "$config" == "$target" ]; then
+      nix build .#nixosConfigurations.{{target}}.config.system.build.toplevel --dry-run --quiet &> /dev/null
+      echo "Target {{target}}'s configuration is valid!"; 
+      exit
+    fi
+  done
+
+  echo "Target '$target' does not exist in the NixOS configurations."