Javascript implementation of an insert value method for hashtables

Hashtable insert value

HashTable.prototype.add = function(key, value) {
  var index = key.hashCode();
  var tuple = [key, value];
  var bucket = this._storage.get(index);
  if (bucket) { 
    for (var i = 0; i < bucket.length; i++) {  
      if (bucket[i][0] === key) {
        bucket[i][1] = value;
      } else {
        bucket.push(tuple);
      }
    } 
  } else {
    this._storage.set(index, [tuple]);
  } 
};

There is a bug in this code, when a bucket is found at given index you iterate over bucket check for current key, if you find a key than you update value and keep iterating over bucket and if key is not found you push tuple in array and keep iterating, for each iteration if no key is found tuple will be pushed to array...
It should be like this.

HashTable.prototype.add = function(key, value) {
  var index = key.hashCode();
  var tuple = [key, value];
  var bucket = this._storage.get(index);
  if (bucket) {
    for (var i = 0; i < bucket.length; i++) {
      if (bucket[i][0] === key) {
        bucket[i][1] = value;
        return;
      }
    }
    bucket.push(tuple);
  } else {
    this._storage.set(index, [tuple]);
  } 
};