fix(zone.bind): throw an error if arg is not a function

Author: mhevery

lib/core.js

@@ -58,6 +58,9 @@ Zone.prototype = {
   },
 
   bind: function (fn, skipEnqueue) {
+    if (typeof fn !== 'function') {
+      throw new Error('Expecting function got: ' + fn);
+    }
     skipEnqueue || this.enqueueTask(fn);
     var zone = this.isRootZone() ? this : this.fork();
     return function zoneBoundFn() {

test/zone.spec.js

@@ -163,6 +163,13 @@ describe('Zone', function () {
         });
       });
     });
+
+
+    it('should throw if argument is not a function', function () {
+      expect(function () {
+        zone.bind(11);
+      }).toThrowError('Expecting function got: 11');
+    });
   });