pimekata.js

primes = function(number){
  divisor = 2;

  while (divisor<number)
  {
    if (number % divisor == 0) return [divisor].concat(primes(number/divisor));
    divisor = divisor + 1;
  }

  if (number == 1) return [];

  return [number];
};
describe("primes", function(){
  it("1 is empty", function(){
    expect(primes(1)).toEqual([]);
  });
  it("2 is 2", function(){
    expect(primes(2)).toEqual([2]);
  });
  it("3 is 3", function(){
    expect(primes(3)).toEqual([3]);
  });
  it("4 is 2,2", function(){
    expect(primes(4)).toEqual([2,2]);
  });
  it("5 is 5", function(){
    expect(primes(5)).toEqual([5]);
  });
  it("6 is 2,3", function(){
    expect(primes(6)).toEqual([2,3]);
  });
  it("7 is 7", function(){
    expect(primes(7)).toEqual([7]);
  });
  it("8 is 2,2,2", function(){
    expect(primes(8)).toEqual([2,2,2]);
  });
  it("9 is 3,3", function(){
    expect(primes(9)).toEqual([3,3]);
  });
});