fixup tests

modules/submodule.nix

@@ -0,0 +1,48 @@
+{ config, lib, ... }:
+
+with lib;
+{
+  imports = [ ./base.nix ];
+
+  options.submodule = {
+    name = mkOption {
+      description = "Module name";
+      type = types.str;
+    };
+
+    description = mkOption {
+      description = "Module description";
+      type = types.str;
+      default = "";
+    };
+
+    version = mkOption {
+      description = "Module version";
+      type = types.str;
+      default = "1.0.0";
+    };
+
+    tags = mkOption {
+      description = "List of submodule tags";
+      type = types.listOf types.str;
+      default = [ ];
+    };
+
+    exports = mkOption {
+      description = "Attribute set of functions to export";
+      type = types.attrs;
+      default = { };
+    };
+
+    passthru = mkOption {
+      description = "Attribute set to passthru";
+      type = types.attrs;
+      default = { };
+    };
+
+    args._empty = mkOption { };
+  };
+
+  config._module.args.args = config.submodule.args;
+  config._m.features = [ "submodule" ];
+}