Fix Node creation crash when using plain object as options (#1424)

When a plain object (e.g., `{ enableRosout: false }`) is passed as options instead of a `NodeOptions` instance, `options.parameterOverrides` is `undefined`, causing `TypeError: Cannot read properties of undefined (reading 'length')`.

Added `Node._normalizeOptions()` to merge plain objects with `NodeOptions.defaultOptions` defaults using nullish coalescing (`??`), ensuring all documented defaults are preserved for unspecified fields while respecting explicitly set values (including `false`).

**Files:**
- `lib/node.js` — added `static _normalizeOptions()`, called at the top of `_init()`
- `test/test-node.js` — added tests for node creation with plain object options and empty object options

Fix: #1423

Author: minggangw

lib/node.js

@@ -97,7 +97,30 @@ class Node extends rclnodejs.ShadowNode {
     );
   }
 
+  static _normalizeOptions(options) {
+    if (options instanceof NodeOptions) {
+      return options;
+    }
+    const defaults = NodeOptions.defaultOptions;
+    return {
+      startParameterServices:
+        options.startParameterServices ?? defaults.startParameterServices,
+      parameterOverrides:
+        options.parameterOverrides ?? defaults.parameterOverrides,
+      automaticallyDeclareParametersFromOverrides:
+        options.automaticallyDeclareParametersFromOverrides ??
+        defaults.automaticallyDeclareParametersFromOverrides,
+      startTypeDescriptionService:
+        options.startTypeDescriptionService ??
+        defaults.startTypeDescriptionService,
+      enableRosout: options.enableRosout ?? defaults.enableRosout,
+      rosoutQos: options.rosoutQos ?? defaults.rosoutQos,
+    };
+  }
+
   _init(name, namespace, options, context, args, useGlobalArguments) {
+    options = Node._normalizeOptions(options);
+
     this.handle = rclnodejs.createNode(
       name,
       namespace,

test/test-node.js

@@ -143,6 +143,25 @@ describe('rclnodejs node test suite', function () {
         );
       });
     });
+
+    it('Create a node with a plain object as options', function () {
+      const node = new rclnodejs.Node('plain_opts_node', '/ns', undefined, {
+        enableRosout: false,
+      });
+      assert.strictEqual(node.name(), 'plain_opts_node');
+      node.destroy();
+    });
+
+    it('Create a node with options missing parameterOverrides', function () {
+      const node = new rclnodejs.Node(
+        'partial_opts_node',
+        '/ns',
+        undefined,
+        {}
+      );
+      assert.strictEqual(node.name(), 'partial_opts_node');
+      node.destroy();
+    });
   });
 });