Fix JS optional-chained member expression.

languages/tree-sitter-stack-graphs-javascript/src/stack-graphs.tsg

@@ -3189,22 +3189,22 @@ inherit .containing_class_value
 ;; ##### Member Expressions
 
 (member_expression
-  (_)@object . (_)@property)@member_expr
-{
-
-    node member_push
-    node property_push
+  object:(_)@object
+  property:(_)@property
+)@member_expr {
+  node member_push
+  node property_push
 
   ; scopes flow into object then back out
   edge @object.before_scope -> @member_expr.before_scope
   edge @member_expr.after_scope -> @object.after_scope
 
   ; value is a member projection on the value of the object ie. a push then push dot
-    attr (member_push) push_symbol = "GUARD:MEMBER"
-    attr (property_push) node_reference = @property
-    edge property_push -> member_push
-    edge @member_expr.value -> property_push
-    edge member_push -> @object.value
+  attr (member_push) push_symbol = "GUARD:MEMBER"
+  attr (property_push) node_reference = @property
+  edge property_push -> member_push
+  edge @member_expr.value -> property_push
+  edge member_push -> @object.value
 
   ; (member_expression) nodes can occur in patterns
   node @member_expr.covalue

languages/tree-sitter-stack-graphs-javascript/test/expressions/member_expression.js

@@ -15,4 +15,9 @@ let x = 1;
 // Flow around
 
 /**/ x;
-//   ^ defined: 1
+//   ^ defined: 1
+
+// Optional chain
+
+/**/ x?.foo
+//   ^ defined: 1