Function boolean

packages/svelte/src/compiler/validate-options.js:296–303

* @param {boolean | undefined} fallback * @returns {Validator}

(fallback)

 * @returns {Validator}
 */
function boolean(fallback) {
	return validator(fallback, (input, keypath) => {
		if (typeof input !== 'boolean') {
			throw_error(`${keypath} should be true or false, if specified`);
		}
		return input;
	});
}

/**
 * @param {Array<boolean | string | number>} options