fix(ui): "a.data.items is undefined" on first run

When enabling the app for the very first time and opening the view, a
toast notification pops up with the following message:

> TypeError: a.data.items is undefined

This is caused by a silenced exception in lib/Controller/ItemController.
Due to it, not a single key is set in the $return array.

Responses returned from such a controller will be serialized as JSON.
However, the returned value is no longer a key-value array, but an
(empty) list and the serializer will convert it to `[]` instead of `{}`
what it should've been.

Now it will return a dummy response containing all the keys but
empty values, causing the serializer to return an object.

Signed-off-by: Vincent Neubauer <[email protected]>

lib/Controller/ItemController.php

@@ -180,9 +180,14 @@ public function index(
             $return['items'] = $this->shareService->mapSharedByDisplayNames($items);
 
             // this gets thrown if there are no items
-            // in that case just return an empty array
+            // in that case just return an empty response
         } catch (ServiceException $ex) {
-            //NO-OP
+            return [
+                'items' => [],
+                'feeds' => [],
+                'newestItemId' => null,
+                'starred' => 0,
+            ];
         }
 
         return $return;

tests/Unit/Controller/ItemControllerTest.php

@@ -455,6 +455,13 @@ public function testItemsOffsetNotZero()
 
     public function testGetItemsNoNewestItemsId()
     {
+        $result = [
+            'items' => [],
+            'feeds' => [],
+            'newestItemId' => null,
+            'starred' => 0
+        ];
+
         $this->itemsApiExpects(2, ListType::FEED);
 
         $this->itemService->expects($this->once())
@@ -463,7 +470,7 @@ public function testGetItemsNoNewestItemsId()
             ->will($this->throwException(new ServiceNotFoundException('')));
 
         $response = $this->controller->index(ListType::FEED, 2, 3);
-        $this->assertEquals([], $response);
+        $this->assertEquals($result, $response);
     }