Fix None filtering, scope serialization, and Assignment RHS scoping

src/openscad_parser/ast/builder.py

@@ -475,14 +475,16 @@ def visit_module_definition(self, node, children):
         # Flatten nested statement lists. Include all statements (assignments,
         # function/module declarations, module instantiations) so scope build
         # can hoist declarations and attach scopes to every node.
+        # Filter out None values that may result from visit_statement() returning
+        # None for statement nodes with no children.
         flattened = []
         stack = list(statement)
         while stack:
             item = stack.pop(0)
             if isinstance(item, list):
                 stack = item + stack
-                continue
-            flattened.append(item)
+            elif item is not None:
+                flattened.append(item)
         return ModuleDeclaration(name=name, parameters=parameters, children=flattened, position=self._get_node_position(node))
 
     def visit_function_definition(self, node, children):

src/openscad_parser/ast/nodes.py

@@ -368,6 +368,11 @@ def __str__(self):
     def build_scope(self, parent_scope: "Scope") -> None:
         self.scope = parent_scope
         self.name.build_scope(parent_scope)
+        # Function literal bodies are closures that resolve variables lazily at
+        # call time, so the RHS always uses parent_scope (the full scope including
+        # the variable being assigned). This correctly handles recursive function
+        # literals and expressions containing function literals
+        # (e.g. `a = b ? function(x,n) a(...) : function(x,n) a(...)`).
         self.expr.build_scope(parent_scope)
 
 

src/openscad_parser/ast/serialization.py

@@ -210,9 +210,10 @@ def _serialize_node(node: ASTNode, include_position: bool) -> dict[str, Any]:
     if include_position:
         result["_position"] = _serialize_position(node.position)
 
-    # Get all fields from the dataclass (excluding 'position' which we handle specially)
+    # Get all fields from the dataclass (excluding 'position' which we handle specially,
+    # and 'scope' which is runtime metadata not suitable for serialization)
     for field in dataclasses.fields(node):
-        if field.name == "position":
+        if field.name in ("position", "scope"):
             continue
         value = getattr(node, field.name)
         result[field.name] = _serialize_value(value, include_position)

tests/test_scope.py

@@ -498,6 +498,21 @@ def test_function_literal_in_expression(self):
         fl = pc.left  # type: ignore
         assert fl.body.scope.lookup_variable("a") is not None  # type: ignore
 
+    def test_function_literal_in_ternary_rhs_sees_assigned_variable(self):
+        """Function literals in a ternary RHS should see the variable being assigned."""
+        ast = getASTfromString("a = b ? function(x, n) a(x + n, n - 1) : function(x, n) a(x * n, n - 1);")
+        assert ast is not None and isinstance(ast, list)
+        build_scopes(ast)
+        assignment = ast[0]
+        ternary = assignment.expr  # type: ignore
+        true_fl = ternary.true_expr  # type: ignore
+        false_fl = ternary.false_expr  # type: ignore
+        assert isinstance(true_fl, FunctionLiteral)
+        assert isinstance(false_fl, FunctionLiteral)
+        # Both function bodies should see 'a' for recursion
+        assert true_fl.body.scope.lookup_variable("a") is not None  # type: ignore
+        assert false_fl.body.scope.lookup_variable("a") is not None  # type: ignore
+
 
 class TestModularCallChildren:
     """Test that module call children get their own scope."""