Object.isSealed.js 774 B

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  1. test("length is 1", () => {
  2. expect(Object.isSealed).toHaveLength(1);
  3. });
  4. describe("normal behavior", () => {
  5. test("returns true for non-object argument", () => {
  6. expect(Object.isSealed(42)).toBeTrue();
  7. expect(Object.isSealed("foobar")).toBeTrue();
  8. });
  9. test("returns false for regular object", () => {
  10. const o = { foo: "bar" };
  11. expect(Object.isSealed(o)).toBeFalse();
  12. });
  13. test("returns true for sealed object", () => {
  14. const o = { foo: "bar" };
  15. Object.seal(o);
  16. expect(Object.isSealed(o)).toBeTrue();
  17. });
  18. test("returns true for non-extensible empty object", () => {
  19. const o = {};
  20. Object.preventExtensions(o);
  21. expect(Object.isSealed(o)).toBeTrue();
  22. });
  23. });