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

title, tags, expertise, cover, firstSeen, lastUpdated

title	tags	expertise	cover	firstSeen	lastUpdated
Argument coalescing factory	function,type	intermediate	blog_images/coffee-phone-tray.jpg	2017-12-18T12:15:36+02:00	2020-10-22T20:23:47+03:00

Customizes a coalesce function that returns the first argument which is true based on the given validator.

• Use Array.prototype.find() to return the first argument that returns true from the provided argument validation function, valid.

const coalesceFactory = valid => (...args) => args.find(valid);

const customCoalesce = coalesceFactory(
  v => ![null, undefined, '', NaN].includes(v)
);
customCoalesce(undefined, null, NaN, '', 'Waldo'); // 'Waldo'