catastrophic backtracking

[preveen-stack]

const regex = /^(a+)+$/;

// Generate a string that triggers catastrophic backtracking
const input = 'aaaaaaaaaaaaaaaaaaaaa!';

if (regex.test(input)) {
  console.log('Matched!');
} else {
  console.log('No match.');
}

[preveen-stack]

const regex = /([a-z]+)+\d+/;

// Generate a string that triggers catastrophic backtracking
const input = 'aaaaaaaaaaaaaaaaaaaaa1';

if (regex.test(input)) {
  console.log('Matched!');
} else {
  console.log('No match.');