A.gd

extends Node
class_name A

func name_func():
	return "foo"


func say_hello():
	name = name_func()
	print("Hello " + name)

B.gd

extends A
class_name B

func name_func():
	return "bar"

node.gd

extends Node


# Called when the node enters the scene tree for the first time.
func _ready():
	var test = B.new()
	test.say_hello()


# Called every frame. 'delta' is the elapsed time since the previous frame.
func _process(delta):
	pass

When I run this (root node is a Node with node.gd as the script), it prints Hello bar