fix(typeahead): fixed waitTime functionality

Closes #573

src/typeahead/test/typeahead.spec.js

@@ -183,6 +183,41 @@ describe('typeahead tests', function () {
       $timeout.flush();
       expect(element).toBeOpenWithActive(1, 0);
     }));
+
+    it('should cancel old timeouts when something is typed within waitTime', inject(function ($timeout) {
+      var values = [];
+      $scope.loadMatches = function(viewValue) {
+        values.push(viewValue);
+        return $scope.source;
+      };
+      var element = prepareInputEl("<div><input ng-model='result' typeahead='item for item in loadMatches($viewValue) | filter:$viewValue' typeahead-wait-ms='200'></div>");
+      changeInputValueTo(element, 'first');
+      changeInputValueTo(element, 'second');
+
+      $timeout.flush();
+
+      expect(values).not.toContain('first');
+    }));
+
+    it('should allow timeouts when something is typed after waitTime has passed', inject(function ($timeout) {
+      var values = [];
+
+      $scope.loadMatches = function(viewValue) {
+        values.push(viewValue);
+        return $scope.source;
+      };
+      var element = prepareInputEl("<div><input ng-model='result' typeahead='item for item in loadMatches($viewValue) | filter:$viewValue' typeahead-wait-ms='200'></div>");
+
+      changeInputValueTo(element, 'first');
+      $timeout.flush();
+
+      expect(values).toContain('first');
+
+      changeInputValueTo(element, 'second');
+      $timeout.flush();
+
+      expect(values).toContain('second');
+    }));
   });
 
   describe('selecting a match', function () {

src/typeahead/typeahead.js

@@ -133,19 +133,20 @@ angular.module('ui.bootstrap.typeahead', ['ui.bootstrap.position'])
       //we need to propagate user's query so we can higlight matches
       scope.query = undefined;
 
+      //Declare the timeout promise var outside the function scope so that stacked calls can be cancelled later 
+      var timeoutPromise;
+
       //plug into $parsers pipeline to open a typeahead on view changes initiated from DOM
       //$parsers kick-in on all the changes coming from the view as well as manually triggered by $setViewValue
       modelCtrl.$parsers.push(function (inputValue) {
 
-        var timeoutId;
-
         resetMatches();
         if (inputValue && inputValue.length >= minSearch) {
           if (waitTime > 0) {
-            if (timeoutId) {
-              $timeout.cancel(timeoutId);//cancel previous timeout
+            if (timeoutPromise) {
+              $timeout.cancel(timeoutPromise);//cancel previous timeout
             }
-            timeoutId = $timeout(function () {
+            timeoutPromise = $timeout(function () {
               getMatchesAsync(inputValue);
             }, waitTime);
           } else {