fix(uiSelectController): invoke onRemove callback method for single select on clear selection

Closes #1225

Author: kuuurt13

src/uiSelectController.js

@@ -454,9 +454,15 @@ uis.controller('uiSelectCtrl',
   };
 
   ctrl.clear = function($event) {
+    var model = angular.copy(ctrl.ngModel.$modelValue);
+
     ctrl.select(null);
     $event.stopPropagation();
     $timeout(function() {
+      ctrl.onRemoveCallback($scope, {
+        $item: ctrl.items[ctrl.activeIndex],
+        $model: model
+      });
       ctrl.focusser[0].focus();
     }, 0, false);
   };

test/select.spec.js

@@ -1425,6 +1425,35 @@ describe('ui-select tests', function () {
 
   });
 
+  it('should invoke remove callback on remove for single select with allowClear enabled', function () {
+    scope.selection.selected = scope.people[5].name;
+
+    scope.onRemoveFn = function ($item, $model) {
+      scope.$item = $item;
+      scope.$model = $model;
+    };
+
+    var el = compileTemplate(
+      '<ui-select on-remove="onRemoveFn($item, $model)" ng-model="selection.selected"> \
+        <ui-select-match allow-clear="true" placeholder="Pick one...">{{$select.selected.name}}</ui-select-match> \
+        <ui-select-choices repeat="person.name as person in people | filter: $select.search"> \
+          <div ng-bind-html="person.name" | highlight: $select.search"></div> \
+          <div ng-bind-html="person.email | highlight: $select.search"></div> \
+        </ui-select-choices> \
+      </ui-select>'
+    );
+
+    expect(scope.$item).toBeFalsy();
+    expect(scope.$model).toBeFalsy();
+
+    el.find('.glyphicon.glyphicon-remove').click();
+    $timeout.flush();
+
+    expect(scope.$item).toBe(scope.people[5]);
+    expect(scope.$model).toBe('Samantha');
+
+  });
+
   it('should set $item & $model correctly when invoking callback on remove and no single prop. binding', function () {
 
     scope.onRemoveFn = function ($item, $model, $label) {