gistfile1.txt

/**
 * @param {number[]} nums
 * @return {number[]}
 */
var productExceptSelf = function(nums) {
  let products = [];
  let product = 1;
  nums.forEach((num, i) => {
    products[i] = product;
    product *= num;
  });
  product = 1;
  for (let i = nums.length - 1; i >= 0; i--) {
    products[i] *= product;
    product *= nums[i];
  }
  return products;
};

class Tests {
  constructor () {
    this.passed = 0;
    this.failed = 0;
  }
  test (val1, val2, name) {
    if (JSON.stringify(val1) === JSON.stringify(val2)) {
      this.passed++;
    } else {
      this.failed++;
      console.error('Failed: ' + name + ', expected ' + val1 + ' to equal ' + val2);
    }
  }
  report () {
    console.log('Passed ' + this.passed + ' tests');
    console.log('Failed ' + this.failed + ' tests');
  }
  run () {
    this.test(productExceptSelf([1, 2, 3]), [6, 3, 2], 'foo');
    this.test(productExceptSelf([2, 3, 4]), [12, 8, 6], 'foo');
    this.test(productExceptSelf([2, 3, 4, 0]), [0, 0, 0, 24], 'foo');
    this.test(productExceptSelf([1, 3, 4, 0]), [0, 0, 0, 12], 'foo');
    this.test(productExceptSelf([24, 31, 5, 13, 7, 433]), [6107465, 4728360, 29315832, 11275320, 20939880, 338520], 'foo');
    this.test(productExceptSelf([-3, 6, -2, 5, 5, 7]), [-2100, 1050, -3150, 1260, 1260, 900], 'Should handle negative numbers');
    this.report();
  }
}

new Tests().run();