Inventory/tests: add more eval smoke tests

lib/inventory/build-inventory/default.nix

@@ -98,7 +98,12 @@ let
             roleModules = builtins.map (
               role:
               let
-                path = clan-core.clanModules.${serviceName} + "/roles/${role}.nix";
+                # Check the module exists
+                module =
+                  clan-core.clanModules.${serviceName}
+                    or (throw "ClanModule not found: '${serviceName}'. Make sure the module is added in the 'clanModules' attribute of clan-core.");
+
+                path = module + "/roles/${role}.nix";
               in
               if builtins.pathExists path then
                 path

lib/inventory/flake-module.nix

@@ -17,13 +17,6 @@ in
       ...
     }:
     let
-      inventory = (
-        import ./build-inventory {
-          clan-core = self;
-          inherit lib;
-        }
-      );
-
       getSchema = import ./interface-to-schema.nix { inherit lib self; };
 
       # The schema for the inventory, without default values, from the module system.
@@ -125,7 +118,7 @@ in
 
       # Run: nix-unit --extra-experimental-features flakes --flake .#legacyPackages.x86_64-linux.evalTests
       legacyPackages.evalTests-inventory = import ./tests {
-        inherit inventory;
+        inherit lib;
         clan-core = self;
       };
 

lib/inventory/tests/default.nix

@@ -1,5 +1,12 @@
-{ inventory, clan-core, ... }:
+{ clan-core, lib, ... }:
 let
+  inventory = (
+    import ../build-inventory {
+
+      inherit lib clan-core;
+    }
+  );
+
   inherit (inventory) buildInventory;
 in
 {
@@ -120,6 +127,30 @@ in
       };
     };
 
+  test_inventory_module_doesnt_exist =
+    let
+      configs = buildInventory {
+        directory = ./.;
+        inventory = {
+          services = {
+            fanatasy.instance_1 = {
+              roles.default.machines = [ "machine_1" ];
+            };
+          };
+          machines = {
+            "machine_1" = { };
+          };
+        };
+      };
+    in
+    {
+      expr = configs;
+      expectedError = {
+        type = "ThrownError";
+        msg = "ClanModule not found*";
+      };
+    };
+
   test_inventory_role_doesnt_exist =
     let
       configs = buildInventory {