isNaN.js 801 B

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  1. test("length is 1", () => {
  2. expect(isNaN).toHaveLength(1);
  3. });
  4. test("arguments that evaluate to false", () => {
  5. expect(isNaN(0)).toBeFalse();
  6. expect(isNaN(42)).toBeFalse();
  7. expect(isNaN("")).toBeFalse();
  8. expect(isNaN("0")).toBeFalse();
  9. expect(isNaN("42")).toBeFalse();
  10. expect(isNaN(true)).toBeFalse();
  11. expect(isNaN(false)).toBeFalse();
  12. expect(isNaN(null)).toBeFalse();
  13. expect(isNaN([])).toBeFalse();
  14. expect(isNaN(Infinity)).toBeFalse();
  15. expect(isNaN(-Infinity)).toBeFalse();
  16. });
  17. test("arguments that evaluate to true", () => {
  18. expect(isNaN()).toBeTrue();
  19. expect(isNaN(NaN)).toBeTrue();
  20. expect(isNaN(undefined)).toBeTrue();
  21. expect(isNaN("foo")).toBeTrue();
  22. expect(isNaN({})).toBeTrue();
  23. expect(isNaN([1, 2, 3])).toBeTrue();
  24. });