Invalid call Nonexistant function file_exists in base nil

Question

I've tried both node and control as the extends. Can anyone tell my why it seems file_exists doesn't seem to be there at all.

extends Node

onready var file = File.new()

func load_data(url) -> Dictionary:
if url == null: return {}
if !file.file_exists(url): return {}
file.open(url, File.READ)
var data:Dictionary = {}
data = parse_json(file.get_as_text())
file.close()
return data

func write_data(url:String, dict:Dictionary):
if url == null: return
file.open(url, File.WRITE)
file.store_line(to_json(dict))
file.close()

Comments

more info... I was originally tryiing to pass in a .bin file as the url. I don't know if that matters. The .bin file isn't seen by godot's filesystem. I've tried changing it to a .txt and a .dat nothing seems to take with 3.1. But the error seems to be with file not seeing fileexists anywhere not the filestring passed into it. Seems like if it was seeing fileexists it would just say false for not being able to see the file.

---

working code

extends Control

#onready var file = File.new()

func load_data(url) -> Dictionary:
var file = File.new()
if url == null: return {}
if !file.file_exists(url): return {}
file.open(url, File.READ)
var data:Dictionary = {}
data = parse_json(file.get_as_text())
file.close()
return data

func write_data(url:String, dict:Dictionary):
var file = File.new()
if url == null: return
file.open(url, File.WRITE)
file.store_line(to_json(dict))
file.close()