[JS] Balanced brackets

brackets.js

const BRACKETS = {
  "(": 1, 
  "[": 2, 
  "{": 3,
  ")": -1, 
  "]": -2,
  "}": -3,
};


function isBalanced(s) {
  const stack = [];
  for(const bracket of s) {
    const curBracketValue = BRACKETS[bracket];
    if(curBracketValue > 0) stack.push(curBracketValue);
    else {
      const lastOpeningBracketValue = stack.pop();
      if(curBracketValue + lastOpeningBracketValue !== 0) return false;
    }
  };
  return stack.length ? false : true;
}

// ---------------------------- Test ----------------------------------//
console.log(isBalanced("")); // true
console.log(isBalanced("{[(])}")); // false
console.log(isBalanced("{{[[(())]]}}")); // true