sharp/lib/is.js

'use strict';

/**
 * Is this value defined and not null?
 * @private
 */
const defined = function (val) {
  return typeof val !== 'undefined' && val !== null;
};

/**
 * Is this value an object?
 * @private
 */
const object = function (val) {
  return typeof val === 'object';
};

/**
 * Is this value a function?
 * @private
 */
const fn = function (val) {
  return typeof val === 'function';
};

/**
 * Is this value a boolean?
 * @private
 */
const bool = function (val) {
  return typeof val === 'boolean';
};

/**
 * Is this value a Buffer object?
 * @private
 */
const buffer = function (val) {
  return object(val) && val instanceof Buffer;
};

/**
 * Is this value a non-empty string?
 * @private
 */
const string = function (val) {
  return typeof val === 'string' && val.length > 0;
};

/**
 * Is this value a real number?
 * @private
 */
const number = function (val) {
  return typeof val === 'number' && !Number.isNaN(val);
};

/**
 * Is this value an integer?
 * @private
 */
const integer = function (val) {
  return number(val) && val % 1 === 0;
};

/**
 * Is this value within an inclusive given range?
 * @private
 */
const inRange = function (val, min, max) {
  return val >= min && val <= max;
};

/**
 * Is this value within the elements of an array?
 * @private
 */
const inArray = function (val, list) {
  return list.indexOf(val) !== -1;
};

module.exports = {
  defined: defined,
  object: object,
  fn: fn,
  bool: bool,
  buffer: buffer,
  string: string,
  number: number,
  integer: integer,
  inRange: inRange,
  inArray: inArray
};