Deep compare two objects in javascript

index.js

// https://www.30secondsofcode.org/articles/s/javascript-object-comparison
const equals = (a, b) => {
  if (a === b) return true;
  if (a instanceof Date && b instanceof Date)
    return a.getTime() === b.getTime();
  if (!a || !b || (typeof a !== 'object' && typeof b !== 'object'))
    return a === b;
  if (a.prototype !== b.prototype) return false;
  const keys = Object.keys(a);
  if (keys.length !== Object.keys(b).length) return false;
  return keys.every(k => equals(a[k], b[k]));
};