Is a string balanced? [Javascript]

is-balanced.js

function isBalanced(string) {
  var balanced = true;
  var parts = string.split('');
  var openBraces = /{|\[|\(/;
  var closeBraces = /}|\]|\)/;
  var stack = [];
  
  for (var i = 0; i < parts.length; i++) {    
    if (parts[i].match(openBraces)) {
      stack.push(parts[i]);
    } else if (parts[i].match(closeBraces)) {
      var lastChar = stack[stack.length - 1];
      if (parts[i] === '}' && lastChar !== '{') {
        balanced = false;
      } else if (parts[i] === ']' && lastChar !== '[') {
        balanced = false;
      } else if (parts[i] === ')' && lastChar !== '(') {
        balanced = false;
      } else {
        stack.pop();
      }
    }
  }
  return balanced;
}

isBalanced('{[()]}'); // => true
isBalanced('{[{}][()]}'); // => true

isBalanced('{]}'); // => false
isBalanced(')({}}'); // => false

Bug found!

isBalanced('{{}'); // => Returns true but should be false

You have to check whether the stack is empty at the end.