fix bug where $eval on undefined throws error

Author: mhevery

src/Scope.js

@@ -130,26 +130,28 @@ function createScope(parent, services, existing) {
     $set: bind(instance, setter, instance),
 
     $eval: function $eval(exp) {
-      if (exp === undefined) {
+      var type = typeof exp;
+      if (type == 'undefined') {
         for ( var i = 0, iSize = evalLists.sorted.length; i < iSize; i++) {
           for ( var queue = evalLists.sorted[i],
               jSize = queue.length,
               j= 0; j < jSize; j++) {
             instance.$tryEval(queue[j].fn, queue[j].handler);
           }
         }
-      } else if (typeof exp === 'function'){
+      } else if (type === 'function') {
         return exp.call(instance);
-      } else {
+      } else  if (type === 'string') {
         return expressionCompile(exp).call(instance);
       }
     },
 
     $tryEval: function (expression, exceptionHandler) {
+      var type = typeof expression;
       try {
-        if (typeof expression == 'function') {
+        if (type == 'function') {
           return expression.call(instance);
-        } else {
+        } else if (type == 'string'){
           return expressionCompile(expression).call(instance);
         }
       } catch (e) {

test/ScopeSpec.js

@@ -21,27 +21,36 @@ describe('scope/model', function(){
   });
 
   describe('$eval', function(){
+    var model;
+
+    beforeEach(function(){model = createScope();});
+
     it('should eval function with correct this', function(){
-      var model = createScope();
       model.$eval(function(){
         this.name = 'works';
       });
       expect(model.name).toEqual('works');
     });
 
     it('should eval expression with correct this', function(){
-      var model = createScope();
       model.$eval('name="works"');
       expect(model.name).toEqual('works');
     });
 
     it('should do nothing on empty string and not update view', function(){
-      var model = createScope();
       var onEval = jasmine.createSpy('onEval');
       model.$onEval(onEval);
       model.$eval('');
       expect(onEval).wasNotCalled();
     });
+
+    it('should ignore none string/function', function(){
+      model.$eval(null);
+      model.$eval({});
+      model.$tryEval(null);
+      model.$tryEval({});
+    });
+
   });
 
   describe('$watch', function(){