types.js

/*!
 * Copyright (c) 2017-2023 Digital Bazaar, Inc. All rights reserved.
 */
'use strict';

const api = {};
module.exports = api;

/**
 * Returns true if the given value is an Array.
 *
 * @param v the value to check.
 *
 * @return true if the value is an Array, false if not.
 */
api.isArray = Array.isArray;

/**
 * Returns true if the given value is a Boolean.
 *
 * @param v the value to check.
 *
 * @return true if the value is a Boolean, false if not.
 */
api.isBoolean = v => (typeof v === 'boolean' ||
  Object.prototype.toString.call(v) === '[object Boolean]');

/**
 * Returns true if the given value is a double.
 *
 * @param v the value to check.
 *
 * @return true if the value is a double, false if not.
 */
api.isDouble = v => api.isNumber(v) &&
  (String(v).indexOf('.') !== -1 || Math.abs(v) >= 1e21);

/**
 * Returns true if the given value is an empty Object.
 *
 * @param v the value to check.
 *
 * @return true if the value is an empty Object, false if not.
 */
api.isEmptyObject = v => api.isObject(v) && Object.keys(v).length === 0;

/**
 * Returns true if the given value is a Number.
 *
 * @param v the value to check.
 *
 * @return true if the value is a Number, false if not.
 */
api.isNumber = v => (typeof v === 'number' ||
  Object.prototype.toString.call(v) === '[object Number]');

/**
 * Returns true if the given value is numeric.
 *
 * @param v the value to check.
 *
 * @return true if the value is numeric, false if not.
 */
api.isNumeric = v => !isNaN(parseFloat(v)) && isFinite(v);

/**
 * Returns true if the given value is an Object.
 *
 * @param v the value to check.
 *
 * @return true if the value is an Object, false if not.
 */
api.isObject = v => v !== null && typeof v === 'object' && !Array.isArray(v);

/**
 * Returns true if the given value is a String.
 *
 * @param v the value to check.
 *
 * @return true if the value is a String, false if not.
 */
api.isString = v => (typeof v === 'string' ||
  Object.prototype.toString.call(v) === '[object String]');

/**
 * Returns true if the given value is undefined.
 *
 * @param v the value to check.
 *
 * @return true if the value is undefined, false if not.
 */
api.isUndefined = v => typeof v === 'undefined';