index.js

var isEmpty = require('is-empty');

try {
  var typeOf = require('type');
} catch (e) {
  var typeOf = require('component-type');
}


/**
 * Types.
 */

var types = [
  'arguments',
  'array',
  'boolean',
  'date',
  'element',
  'function',
  'null',
  'number',
  'object',
  'regexp',
  'string',
  'undefined'
];


/**
 * Expose type checkers.
 *
 * @param {Mixed} value
 * @return {Boolean}
 */

for (var i = 0, type; type = types[i]; i++) exports[type] = generate(type);


/**
 * Add alias for `function` for old browsers.
 */

exports.fn = exports['function'];


/**
 * Expose `empty` check.
 */

exports.empty = isEmpty;


/**
 * Expose `nan` check.
 */

exports.nan = function (val) {
  return exports.number(val) && val != val;
};


/**
 * Generate a type checker.
 *
 * @param {String} type
 * @return {Function}
 */

function generate (type) {
  return function (value) {
    return type === typeOf(value);
  };
}