Argument coalescing factory

OSCC · JavaScript, Function, Type · Oct 22, 2020

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'

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