updae test spec

README.md

@@ -21,11 +21,23 @@ $ npm install --save is-native
 ```js
 var isNative = require('is-native');
 
+var obj = { a: 1 };
+var arr = [1, 2, 3];
+
+isNative(obj.valueOf); // => true
+isNative(arr.push);    // => true
 isNative(Math.min);    // => true
 isNative(console.log); // => true
 
 isNative(function () { console.log(123); });              
 // => false
+
+isNative();          // => false
+isNative(obj);       // => false
+isNative(arr);       // => false
+isNative(/x/);       // => false
+isNative(new Date);  // => false
+isNative(new Error); // => false
 ```
 
 

index.js

@@ -5,9 +5,12 @@ var toSource = require('to-source-code');
 
 function isObject(value) {
 
-  var type = typeof value;
+  if (!value) {
+    return false;
+  }
 
-  return !!value && (type === 'object' || type === 'function');
+  var type = typeof value;
+  return type === 'object' || type === 'function';
 }
 
 // Checks if `value` is a host object in IE < 9.
@@ -17,7 +20,6 @@ function isHostObject(value) {
   // despite having improperly defined `toString` methods.
 
   var result = false;
-
   if (!isNil(value) && typeof value.toString !== 'function') {
     try {
       result = ('' + value) !== '';
@@ -27,9 +29,7 @@ function isHostObject(value) {
 }
 
 function isFunction(value) {
-
   var tag = isObject(value) ? Object.prototype.toString.call(value) : '';
-
   return tag === '[object Function]' || tag === '[object GeneratorFunction]';
 }
 
@@ -40,23 +40,23 @@ module.exports = function (value) {
     return false;
   }
 
-  var pattern;
-
   if (isFunction(value) || isHostObject(value)) {
 
-    var toString       = Function.prototype.toString;
+    var fnToString     = Function.prototype.toString;
     var hasOwnProperty = Object.prototype.hasOwnProperty;
-    var reRegExpChar   = /[\\^$.*+?()[\]{}|]/g;
 
-    pattern = new RegExp('^' +
-      toString.call(hasOwnProperty)
-        .replace(reRegExpChar, '\\$&')
+    var reIsNative = new RegExp('^' +
+      fnToString
+        .call(hasOwnProperty)
+        .replace(/[\\^$.*+?()[\]{}|]/g, '\\$&')
         .replace(/hasOwnProperty|(function).*?(?=\\\()| for .+?(?=\\\])/g, '$1.*?') + '$'
     );
-  } else {
-    // detect host constructors (Safari).
-    pattern = /^\[object .+?Constructor\]$/;
+
+    return reIsNative.test(toSource(value));
   }
 
-  return pattern.test(toSource(value));
+  // used to detect host constructors (Safari > 4; really typed array specific)
+  var reIsHostCtor = /^\[object .+?Constructor\]$/;
+
+  return reIsHostCtor.test(toSource(value));
 };

test/spec/index.js

@@ -1,14 +1,21 @@
-'use strict';
-
 var expect = require('chai').expect;
 
-
 describe('is-native', function () {
 
   var isNative = require('../../');
 
-  it('common test', function () {
+  it('should return `true` for native methods', function () {
+
+    var obj = { a: 1 };
+    var arr = [1, 2, 3];
+
+    expect(isNative(obj.valueOf)).to.be.true;
+    expect(isNative(arr.push)).to.be.true;
     expect(isNative(Math.min)).to.be.true;
+  });
+
+  it('should return `false` for non-native methods', function () {
+
     expect(isNative(function () {})).to.be.false;
 
     expect(isNative()).to.be.false;
@@ -17,8 +24,11 @@ describe('is-native', function () {
     expect(isNative('abc')).to.be.false;
     expect(isNative(void 0)).to.be.false;
     expect(isNative(true)).to.be.false;
-    expect(isNative({})).to.be.false;
-    expect(isNative([])).to.be.false;
+    expect(isNative({ a: 1 })).to.be.false;
+    expect(isNative([1, 2, 3])).to.be.false;
     expect(isNative(NaN)).to.be.false;
+    expect(isNative(/x/)).to.be.false;
+    expect(isNative(new Date)).to.be.false;
+    expect(isNative(new Error)).to.be.false;
   });
 });