feat(test): add simple submodule test

submodules.nix

@@ -67,7 +67,7 @@ let
       version = mkOption {
         description = "Module version";
         type = types.str;
-        default = "0.0.0";
+        default = null;
       };
 
       passthru = mkOption {

test/default.nix

@@ -16,6 +16,7 @@ with lib;
       testing.tests = [
         ./k8s/simple.nix
         ./k8s/deployment.nix
+        ./submodules/simple.nix
       ];
     }
   ];

test/submodules/simple.nix

@@ -0,0 +1,41 @@
+{ config, lib, kubenix, ... }:
+
+with lib;
+
+{
+  imports = [
+    kubenix.submodules
+  ];
+
+  test = {
+    name = "submodules/simple";
+    description = "Simple k8s submodule test";
+    assertions = [{
+      message = "Submodule name is set";
+      assertion = config.submodules.instances.empty.name == "empty";
+    } {
+      message = "Submodule version is set";
+      assertion = config.submodules.instances.empty.version == null;
+    } {
+      message = "Submodule config has submodule definition";
+      assertion = config.submodules.instances.empty.config.submodule.name == "empty";
+    } {
+      message = "Should have argument set";
+      assertion = config.submodules.instances.empty.config.args.value == "test";
+    }];
+  };
+
+  submodules.imports = [{
+    module = {
+      config.submodule.name = "empty";
+      options.args.value = mkOption {
+        description = "Submodule argument";
+        type = types.str;
+      };
+    };
+  }];
+
+  submodules.instances.empty = {
+    config.args.value = "test";
+  };
+}