Refactoring day1

node_modules/is-number/index.js

@@ -1,22 +1,18 @@
 /*!
  * is-number <https://github.com/jonschlinkert/is-number>
  *
- * Copyright (c) 2014-2015, Jon Schlinkert.
- * Licensed under the MIT License.
+ * Copyright (c) 2014-present, Jon Schlinkert.
+ * Released under the MIT License.
  */
 
 'use strict';
 
-var typeOf = require('kind-of');
-
-module.exports = function isNumber(num) {
-  var type = typeOf(num);
-
-  if (type === 'string') {
-    if (!num.trim()) return false;
-  } else if (type !== 'number') {
-    return false;
+module.exports = function(num) {
+  if (typeof num === 'number') {
+    return num - num === 0;
   }
-
-  return (num - num + 1) >= 0;
+  if (typeof num === 'string' && num.trim() !== '') {
+    return Number.isFinite ? Number.isFinite(+num) : isFinite(+num);
+  }
+  return false;
 };