text: var Triangle = require('./pascals-triangle');
  
  describe('Triangle', function () {
    it('with one row', function () {
      expect(new Triangle(1).rows).toEqual([[1]]);
    });
  
    it('with two rows', function () {
      expect(new Triangle(2).rows).toEqual([[1], [1, 1]]);
    });
  
    it('with three rows', function () {
      expect(new Triangle(3).rows).toEqual([[1], [1, 1], [1, 2, 1]]);
    });
  
    it('last row', function () {
      expect(new Triangle(4).lastRow).toEqual([1, 3, 3, 1]);
    });
  
    it('fifth row', function () {
      expect(new Triangle(5).lastRow).toEqual([1, 4, 6, 4, 1]);
    });
  
    it('twentieth row', function () {
      var twentieth = [1, 19, 171, 969, 3876, 11628, 27132, 50388, 75582, 92378, 92378, 75582, 50388, 27132, 11628, 3876, 969, 171, 19, 1];
      expect(new Triangle(20).lastRow)
        .toEqual(twentieth);
    });
  });
  