fix(extractors): handle parameterized_arguments for ObjC protocol adoption (#1106)

The JS extractor was looking up 'protocol_qualifiers' which doesn't exist in
tree-sitter-objc v3 (the grammar wraps adopted protocols in
'parameterized_arguments' instead). As a result every '@interface Foo : NSObject
<Bar, Baz>' silently dropped its 'implements' relations on the JS side, while
the Rust extractor correctly extracted them. Mirror handle_class_interface in
crates/codegraph-core/src/extractors/objc.rs (parameterized_arguments + the
type_name > type_identifier nesting) and add a regression test.

Author: carlos-alm

src/extractors/objc.ts

@@ -114,13 +114,24 @@ function handleClassInterface(node: TreeSitterNode, ctx: ExtractorOutput): void
     ctx.classes.push({ name, extends: superclass.text, line: node.startPosition.row + 1 });
   }
 
-  // Protocols
-  const protocols = findChild(node, 'protocol_qualifiers');
+  // Adopted protocols. tree-sitter-objc v3 wraps the adopted-protocol list in
+  // `parameterized_arguments` (not `protocol_qualifiers`, which was the v2
+  // grammar shape). Each child is wrapped in `type_name > type_identifier`;
+  // fall back to a bare `identifier`/`type_identifier` for older grammars.
+  const protocols = findChild(node, 'parameterized_arguments');
   if (protocols) {
     for (let i = 0; i < protocols.childCount; i++) {
       const proto = protocols.child(i);
-      if (proto && proto.type === 'identifier') {
-        ctx.classes.push({ name, implements: proto.text, line: node.startPosition.row + 1 });
+      if (!proto) continue;
+      let protoName: string | null = null;
+      if (proto.type === 'type_name') {
+        const inner = findChild(proto, 'type_identifier') || findChild(proto, 'identifier');
+        if (inner) protoName = inner.text;
+      } else if (proto.type === 'identifier' || proto.type === 'type_identifier') {
+        protoName = proto.text;
+      }
+      if (protoName) {
+        ctx.classes.push({ name, implements: protoName, line: node.startPosition.row + 1 });
       }
     }
   }

tests/parsers/objc.test.ts

@@ -111,6 +111,25 @@ describe('Objective-C parser', () => {
     ]);
   });
 
+  it('extracts adopted protocols as implements relations', () => {
+    // tree-sitter-objc v3 wraps the adopted-protocol list in
+    // `parameterized_arguments` (not the legacy `protocol_qualifiers`). The
+    // JS extractor must mirror `handle_class_interface` in
+    // `crates/codegraph-core/src/extractors/objc.rs`, otherwise every
+    // `implements` relation for an ObjC class interface is silently dropped.
+    const symbols = parseObjC(`@interface Foo : NSObject <Bar, Baz>
+@end`);
+    expect(symbols.classes).toContainEqual(
+      expect.objectContaining({ name: 'Foo', extends: 'NSObject' }),
+    );
+    expect(symbols.classes).toContainEqual(
+      expect.objectContaining({ name: 'Foo', implements: 'Bar' }),
+    );
+    expect(symbols.classes).toContainEqual(
+      expect.objectContaining({ name: 'Foo', implements: 'Baz' }),
+    );
+  });
+
   it('extracts @property names nested under struct_declarator', () => {
     // The v3 grammar does not expose `name` as a named field on
     // `property_declaration`; the identifier nests under