fix(extractor): resolve arrow-function rest-param bindings via enclosing variable_declarator (#1331)

extractObjectRestParamBindingsWalk checked childForFieldName('name') on
every function node, but arrow_function and function_expression nodes have
no name field in the tree-sitter grammar — so const f = ({ ...rest }) => {}
always produced an undefined funcName and silently skipped the entire
parameter scan.

Fix: when childForFieldName('name') returns null and the parent node is a
variable_declarator, fall back to the declarator's own name field. This
mirrors the same pattern used in extractSpreadForOfWalk for arrow functions.

Closes the gap reported in the Greptile review (comment 3367102930).

Author: carlos-alm

src/extractors/javascript.ts

@@ -2070,7 +2070,14 @@ function extractObjectRestParamBindingsWalk(
     if (depth >= MAX_WALK_DEPTH) return;
     const t = node.type;
     if (t === 'function_declaration' || t === 'function_expression' || t === 'arrow_function') {
-      const nameNode = node.childForFieldName('name');
+      // `function_declaration` has a `name` field; `arrow_function` and
+      // `function_expression` do not — get the name from the enclosing
+      // `variable_declarator` instead (e.g. `const f3 = ({ ...rest }) => {}`).
+      const nameNode =
+        node.childForFieldName('name') ??
+        (node.parent?.type === 'variable_declarator'
+          ? node.parent.childForFieldName('name')
+          : null);
       const funcName = nameNode?.text;
       if (funcName) {
         const paramsNode =