least factor with switch-catch

factor.js

function leastFactor(n) {
  switch (false) {
    case !(n === 0):
      return 0;
    case !(n % 1 || n * n < 2):
      return 1;
    case !(n % 2 === 0):
      return 2;
    case !(n % 3 === 0):
      return 3;
    case !(n % 5 === 0):
      return 5;
  }

  var m = Math.sqrt(n);
  for (var i = 7; i <= m; i += 30) {
    switch (false) {
      case !(n % i === 0):
        return i;
      case !(n % (i + 4) === 0):
        return i + 4;
      case !(n % (i + 6) === 0):
        return i + 6;
      case !(n % (i + 10) === 0):
        return i + 10;
      case !(n % (i + 12) === 0):
        return i + 12;
      case !(n % (i + 16) === 0):
        return i + 16;
      case !(n % (i + 22) === 0):
        return i + 22;
      case !(n % (i + 24) === 0):
        return i + 24;
    }
  }
  return n;
}