fix(typeahead): add support for ngModelOptions getterSetter

- Add support for getterSetter with ngModelOptions

src/typeahead/test/typeahead.spec.js

@@ -709,6 +709,19 @@ describe('typeahead tests', function () {
 
       expect($scope.test.typeahead.$error.parse).toBeUndefined();
     });
+
+    it('issue #3823 - should support ng-model-options getterSetter', function () {
+      function resultSetter(state) {
+        return state;
+      }
+      $scope.result = resultSetter;
+      var element = prepareInputEl('<div><input name="typeahead" ng-model="result" ng-model-options="{getterSetter: true}" typeahead="state as state.name for state in states | filter:$viewValue" typeahead-editable="false"></div>');
+
+      changeInputValueTo(element, 'Alaska');
+      triggerKeyDown(element, 13);
+
+      expect($scope.result).toBe(resultSetter);
+    });
   });
 
   describe('input formatting', function () {

src/typeahead/typeahead.js

@@ -35,9 +35,10 @@ angular.module('ui.bootstrap.typeahead', ['ui.bootstrap.position', 'ui.bootstrap
   var HOT_KEYS = [9, 13, 27, 38, 40];
 
   return {
-    require:'ngModel',
-    link:function (originalScope, element, attrs, modelCtrl) {
-
+    require:['ngModel', '^?ngModelOptions'],
+    link:function (originalScope, element, attrs, ctrls) {
+      var modelCtrl = ctrls[0];
+      var ngModelOptions = ctrls[1];
       //SUPPORTED ATTRIBUTES (OPTIONS)
 
       //minimal no of characters that needs to be entered before typeahead kicks-in
@@ -67,7 +68,16 @@ angular.module('ui.bootstrap.typeahead', ['ui.bootstrap.position', 'ui.bootstrap
       //INTERNAL VARIABLES
 
       //model setter executed upon match selection
-      var $setModelValue = $parse(attrs.ngModel).assign;
+      var parsedModel = $parse(attrs.ngModel);
+      var invokeModelSetter = $parse(attrs.ngModel + '($$$p)');
+      var $setModelValue = function(scope, newValue) {
+        if (angular.isFunction(parsedModel(originalScope)) &&
+          ngModelOptions && ngModelOptions.$options && ngModelOptions.$options.getterSetter) {
+          return invokeModelSetter(scope, {$$$p: newValue});
+        } else {
+          return parsedModel.assign(scope, newValue);
+        }
+      };
 
       //expressions used by typeahead
       var parserResult = typeaheadParser.parse(attrs.typeahead);