Edit in JSFiddle

const bracketValidation = (input) => {
   const openers = ["{", "[", "("];
   const closers = ["}", "]", ")"];
   const match = {
     "}": "{",
     "]": "[",
     ")": "("
   };
   let lastOpener = [];
   for (let i = 0; i < input.length; i++) {
     if (openers.includes(input[i])) {
       lastOpener.push(input[i]);
     }
     if (closers.includes(input[i])) {
       const last = lastOpener.pop();
       if (last !== match[input[i]]) {
         return false;
       }
     }
   }
   return lastOpener.length == 0;
 }
 const testCode = (codeoutput, correctoutput) => {
  console.log("actual", codeoutput, "expected", correctoutput);
}

testCode(bracketValidation(""), true);
testCode(bracketValidation("{{{}}}"), true);
testCode(bracketValidation("{{{}}}]"), false);