ladybird/Userland/Libraries/LibJS/Tests/builtins/Object/Object.isExtensible.js
2021-01-12 12:17:46 +01:00

18 lines
624 B
JavaScript

test("basic functionality", () => {
expect(Object.isExtensible).toHaveLength(1);
expect(Object.isExtensible()).toBeFalse();
expect(Object.isExtensible(undefined)).toBeFalse();
expect(Object.isExtensible(null)).toBeFalse();
expect(Object.isExtensible(true)).toBeFalse();
expect(Object.isExtensible(6)).toBeFalse();
expect(Object.isExtensible("test")).toBeFalse();
let s = Symbol();
expect(Object.isExtensible(s)).toBeFalse();
let o = { foo: "foo" };
expect(Object.isExtensible(o)).toBeTrue();
Object.preventExtensions(o);
expect(Object.isExtensible(o)).toBeFalse();
});