/**
 * Check if a number is an Humber number.
 *
 * Humble numbers are positive integers which have
 * no prime factors > 7.
 *
 * Source: https://rosettacode.org/wiki/Humble_numbers
 *
 * @param n - The number to be checked,
 *            superior or equal to zero and up to 2**31 -1
 */
declare function isHumbleNumber(n: number): boolean;

it("should consider any prime number <=7 as humble", () => {
  expect(isHumbleNumber(2)).toBe(true);
  expect(isHumbleNumber(3)).toBe(true);
  expect(isHumbleNumber(5)).toBe(true);
  expect(isHumbleNumber(7)).toBe(true);
});

it("should consider any number <=7 as humble", () => {
  expect(isHumbleNumber(0)).toBe(true);
  expect(isHumbleNumber(1)).toBe(true);
  expect(isHumbleNumber(4)).toBe(true);
  expect(isHumbleNumber(6)).toBe(true);
});

it("should consider any compositite of 2, 3, 5 or 7 as humble", () => {
  expect(isHumbleNumber(2 * 2 * 2 * 2 * 2)).toBe(true);
  expect(isHumbleNumber(2 * 2 * 3 * 3 * 5 * 5 * 7 * 7)).toBe(true);
});

it("should consider number with prime factor >7 as non-humble", () => {
  expect(isHumbleNumber(11)).toBe(false);
  expect(isHumbleNumber(2 * 11)).toBe(false);
});