isArguments method

paulmillr · Feb 14, 2014 · 69857e9 · 69857e9
1 parent d2390a2
commit 69857e9
Showing 1 changed file with 16 additions and 0 deletions.
diff --git a/es6-shim.js b/es6-shim.js
@@ -82,6 +82,22 @@
       defineProperties(prototype, o);
     };
 
+    // taken directly from https://github.com/ljharb/is-arguments/blob/master/index.js
+    // can be replaced with require('is-arguments') if we ever use a build process instead
+    var isArguments = function isArguments(value) {
+      var str = _toString.call(value);
+      var isArguments = str === '[object Arguments]';
+      if (!isArguments) {
+        isArguments = str !== '[object Array]'
+          && value !== null
+          && typeof value === 'object'
+          && typeof value.length === 'number'
+          && value.length >= 0
+          && toString.call(value.callee) === '[object Function]';
+      }
+      return isArguments;
+    };
+
     var ES = {
       CheckObjectCoercible: function(x, optMessage) {
         if (x == null)