ow/test/optional.ts

import test from 'ava';
import ow from '../source';

test('optional', t => {
	t.notThrows(() => {
		ow(1, ow.optional.number);
	});

	t.notThrows(() => {
		ow(undefined, ow.optional.number);
	});

	t.notThrows(() => {
		ow(undefined, ow.optional.string.minLength(3));
	});

	t.notThrows(() => {
		ow(undefined, ow.optional.any(ow.string, ow.number));
	});

	t.throws(() => {
		// tslint:disable-next-line
		ow(null, ow.optional.number);
	}, 'Expected argument to be of type `number` but received type `null`');

	t.throws(() => {
		ow('1' as any, ow.optional.number);
	}, 'Expected argument to be of type `number` but received type `string`');
});