JS check is Prime Number

isPrimeNumber

function isPrime(number) {
    var start = 2, end = Math.sqrt(number);

    while (start <= end) {
        start++;
        if (number % start < 1)
            return false;
    }
    return number > 1;
}


// Test
eq(false, isPrime(1));
eq(true, isPrime(2));
eq(true, isPrime(3));
eq(true, isPrime(5));
eq(true, isPrime(7));
eq(true, isPrime(11));
eq(true, isPrime(13));
eq(true, isPrime(17));
eq(true, isPrime(23));
eq(true, isPrime(29));
eq(true, isPrime(31));
eq(true, isPrime(37));
eq(true, isPrime(41));


function eq(exp, val) {
  if (Array.isArray(exp) && Array.isArray(val)){
    if (exp.toString() !== val.toString()) {
      console.log('FATAL, array expected:`'+exp+'`\n              but was:`'+val+'`');
    }
  } else if (typeof exp === 'object' && typeof val === 'object') {
    if (JSON.stringify(exp) !== JSON.stringify(val)){
      console.log('FATAL, object expected:`'+JSON.stringify(exp)+'`\n               but was:`'+JSON.stringify(val)+'`');
    }
  } else {
    if (exp !== val){
      console.log('FATAL, expected:`'+exp+'`\n        but was:`'+val+'`');
    }
  }
}