30-seconds-of-code/snippets/unwind.md

title, tags, expertise, author, cover, firstSeen

title	tags	expertise	author	cover	firstSeen
Unwind object	object	intermediate	chalarangelo	blog_images/waves-from-above.jpg	2022-04-18T05:00:00-04:00

Produces an array of objects from an object and one of its array-valued properties.

• Use object destructuring to exclude the key-value pair for the specified key from the object.
• Use Array.prototype.map() for the values of the given key to create an array of objects.
• Each object contains the original object's values, except for key which is mapped to its individual values.

const unwind = (key, obj) => {
  const { [key]: _, ...rest } = obj;
  return obj[key].map(val => ({ ...rest, [key]: val }));
};

unwind('b', { a: true, b: [1, 2] }); // [{ a: true, b: 1 }, { a: true, b: 2 }]