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30-seconds-of-code/snippets/coalesceFactory.md
Mathias Bynens f2e5e26af3 Avoid confusing prototype methods for static methods
Correct: `Array.from()` (it’s a static method)
Incorrect: `Array.join()` (doesn’t exist; it’s a prototype method)

This patch uses the common `#` syntax to denote `.prototype.`.
2018-09-28 15:44:12 -04:00

521 B

coalesceFactory

Returns a customized coalesce function that returns the first argument that returns true from the provided argument validation function.

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

const coalesceFactory = valid => (...args) => args.find(valid);
const customCoalesce = coalesceFactory(_ => ![null, undefined, '', NaN].includes(_));
customCoalesce(undefined, null, NaN, '', 'Waldo'); // "Waldo"