Validate the order of parenthese in an expression

const brackets = ["(", ")"];

/**
 * validates the order of parenthese in a string
 * @param {*} type string 
 * @returns boolean otherwise `throws an error`
 */
const checkSyntax = (str) => {
  if (typeof str !== "string") return false;

  //check if both of the brackets dont exists
  if (str.indexOf(brackets[0]) === -1 && str.indexOf(brackets[1]) === -1)
    return true;

  // check if one of the brackets exists.
  if (
    (str.indexOf(brackets[0]) === -1 && str.indexOf(brackets[1]) !== -1) ||
    (str.indexOf(brackets[1]) === -1 && str.indexOf(brackets[0]) !== -1)
  )
    throw new Error(
      `Syntax error: ${str[str.length - 1]} at index ${[str.length - 1]}`
    );

  //check if ) is at index 0  or ( is a last index throw otherwise skip
  if (str[0] === brackets[1] || str[str.length - 1] === brackets[0])
    throw new Error(`Error ==> index ${[str.length - 1]}`);

  //Here we now check for validity
  let stack = [];

  for (let i = 0; i < str.length; i++) {

    if (str[i] === brackets[0]) {
      stack.push(str[i]);
      continue;
    }

    if (str[i] === brackets[1]) {

      //if we are trying to pop an empty stack []
      if (!stack.length) throw new Error(`Error : not in order ${i}`);

      stack.pop(str[i]);

      //if the stack is not empty and i is on the last iteration then throw otherwise skip
      if (stack.length !== 0 && i === str.length - 1)
        throw new Error(
          `Syntax Error : stack is not empty i.e stack length = [${stack.length}]`
        );

      continue;
    }
  }

  return true;
};

console.log(checkSyntax("((()))()()()")); //true