Node.js Built-in Test Runner

const assert = require("assert");

function isPalindrome(s) {
  const clean = s.toLowerCase().replace(/[^a-z0-9]/g, "");
  return clean === [...clean].reverse().join("");
}

const cases = [
  ["racecar", true],
  ["A man, a plan, a canal: Panama", true],
  ["hello", false],
];

for (const [input, expected] of cases) {
  assert.strictEqual(isPalindrome(input), expected);
  console.log("pass:", input);
}

assert.deepStrictEqual({ a: [1, 2] }, { a: [1, 2] });
assert.throws(() => JSON.parse("{bad"), SyntaxError);
console.log("all assertions passed");

pass: racecar
pass: A man, a plan, a canal: Panama
pass: hello
all assertions passed