diff --git a/AUTHORS.md b/AUTHORS.md
index 56f3aceb1c..3d3d07094a 100644
--- a/AUTHORS.md
+++ b/AUTHORS.md
@@ -157,4 +157,10 @@
 * [waffshappen](mailto:44290023+waffshappen@users.noreply.github.com)
 * [wizdude](mailto:wizdude@users.noreply.github.com)
 * [zero77](mailto:zero77@users.noreply.github.com)
-* [Éloi Rivard](mailto:eloi.rivard@aquilenet.fr)
\ No newline at end of file
+* [Éloi Rivard](mailto:eloi.rivard@aquilenet.fr)
+* [Marco Nassabain](mailto:marco.nassabain@hotmail.com)
+* [Nicolas Wendling](mailto:nicolas.wendling1011@gmail.com)
+* [Jimmy Huynh](mailto:natorisaki@gmail.com)
+* [Aurélien David](mailto:dav.aurelien@gmail.com)
+* [Hamza Elhaddad](mailto:elhaddadhamza49@gmail.com)
+* [Ilyes Chergui-Malih](mailto:ilyes.chergui.malih@outlook.fr)
\ No newline at end of file
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 358a199cbf..5fff081c88 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -25,6 +25,11 @@ The format is almost based on [Keep a Changelog](https://keepachangelog.com/en/1
 - Search: Add folder search (#1215)
 - Improve test coverage (#1263)
 - Allow directly adding a feed without going through the discovery process (#1265)
+- Implemented sharing news items between nextcloud users (#1191)
+- Updated the news items table in DB to include sharer data (#1191)
+- Added route for sharing news items (#1191)
+- Added share data in news items serialization (#1191)
+- Added tests for the news items share feature (#1191)
 
 ### Fixed
 - Do not show deleted feeds in item list (#1214)
diff --git a/appinfo/routes.php b/appinfo/routes.php
index a50f4a5b7e..b938d4fb51 100644
--- a/appinfo/routes.php
+++ b/appinfo/routes.php
@@ -52,6 +52,7 @@
 ['name' => 'item#read', 'url' => '/items/{itemId}/read', 'verb' => 'POST'],
 ['name' => 'item#read_multiple', 'url' => '/items/read/multiple', 'verb' => 'POST'],
 ['name' => 'item#star', 'url' => '/items/{feedId}/{guidHash}/star', 'verb' => 'POST'],
+['name' => 'item#share', 'url' => '/items/{itemId}/share/{shareRecipientId}', 'verb' => 'POST'],
 
 // export
 ['name' => 'export#opml', 'url' => '/export/opml', 'verb' => 'GET'],
diff --git a/lib/Controller/ItemController.php b/lib/Controller/ItemController.php
index 85f67ef7a9..4d2050e63e 100644
--- a/lib/Controller/ItemController.php
+++ b/lib/Controller/ItemController.php
@@ -24,6 +24,7 @@
 use \OCA\News\Service\Exceptions\ServiceException;
 use \OCA\News\Service\Exceptions\ServiceNotFoundException;
 use \OCA\News\Service\ItemServiceV2;
+use \OCA\News\Service\ShareService;
 use OCP\IUserSession;
 
 /**
@@ -43,6 +44,10 @@ class ItemController extends Controller
      * @var FeedServiceV2
      */
     private $feedService;
+    /**
+     * @var ShareService
+     */
+    private $shareService;
     /**
      * @var IConfig
      */
@@ -52,12 +57,14 @@ public function __construct(
         IRequest $request,
         FeedServiceV2 $feedService,
         ItemServiceV2 $itemService,
+        ShareService $shareService,
         IConfig $settings,
         ?IUserSession $userSession
     ) {
         parent::__construct($request, $userSession);
         $this->itemService = $itemService;
         $this->feedService = $feedService;
+        $this->shareService = $shareService;
         $this->settings = $settings;
     }
 
@@ -169,7 +176,8 @@ public function index(
                     );
                     break;
             }
-            $return['items'] = $items;
+            // Map sharer display names onto shared items
+            $return['items'] = $this->shareService->mapSharedByDisplayNames($items);
 
             // this gets thrown if there are no items
             // in that case just return an empty array
@@ -229,7 +237,8 @@ public function newItems(int $type, int $id, $lastModified = 0): array
             $return['newestItemId'] = $this->itemService->newest($this->getUserId())->getId();
             $return['feeds'] = $this->feedService->findAllForUser($this->getUserId());
             $return['starred'] = count($this->itemService->starred($this->getUserId()));
-            $return['items'] = $items;
+            // Map sharer display names onto shared items
+            $return['items'] = $this->shareService->mapSharedByDisplayNames($items);
 
             // this gets thrown if there are no items
             // in that case just return an empty array
@@ -318,4 +327,26 @@ public function readMultiple(array $itemIds): void
             }
         }
     }
+
+
+    /**
+     * @NoAdminRequired
+     *
+     * @param int $itemId              Item to share
+     * @param string $shareRecipientId User to share the item with
+     */
+    public function share(int $itemId, string $shareRecipientId)
+    {
+        try {
+            $this->shareService->shareItemWithUser(
+                $this->getUserId(),
+                $itemId,
+                $shareRecipientId
+            );
+        } catch (ServiceNotFoundException $ex) {
+            return $this->error($ex, Http::STATUS_NOT_FOUND);
+        }
+
+        return [];
+    }
 }
diff --git a/lib/Db/Item.php b/lib/Db/Item.php
index 221fb8627d..2ead77066c 100644
--- a/lib/Db/Item.php
+++ b/lib/Db/Item.php
@@ -67,6 +67,10 @@ class Item extends Entity implements IAPI, \JsonSerializable
     protected $starred = false;
     /** @var string|null */
     protected $categoriesJson;
+    /** @var string|null */
+    protected $sharedBy;
+    /** @var string|null */
+    protected $sharedByDisplayName;
 
     public function __construct()
     {
@@ -90,6 +94,33 @@ public function __construct()
         $this->addType('unread', 'boolean');
         $this->addType('starred', 'boolean');
         $this->addType('categoriesJson', 'string');
+        $this->addType('sharedBy', 'string');
+    }
+
+    public function __clone()
+    {
+        $this->resetUpdatedFields();
+        $this->markFieldUpdated('contentHash');
+        $this->markFieldUpdated('guidHash');
+        $this->markFieldUpdated('guid');
+        $this->markFieldUpdated('url');
+        $this->markFieldUpdated('title');
+        $this->markFieldUpdated('author');
+        $this->markFieldUpdated('pubDate');
+        $this->markFieldUpdated('body');
+        $this->markFieldUpdated('enclosureMime');
+        $this->markFieldUpdated('enclosureLink');
+        $this->markFieldUpdated('mediaThumbnail');
+        $this->markFieldUpdated('mediaDescription');
+        $this->markFieldUpdated('feedId');
+        $this->markFieldUpdated('lastModified');
+        $this->markFieldUpdated('searchIndex');
+        $this->markFieldUpdated('rtl');
+        $this->markFieldUpdated('fingerprint');
+        $this->markFieldUpdated('unread');
+        $this->markFieldUpdated('starred');
+        $this->markFieldUpdated('categoriesJson');
+        $this->markFieldUpdated('sharedBy');
     }
 
     /**
@@ -285,6 +316,16 @@ public function isUnread(): bool
         return $this->unread;
     }
 
+    public function getSharedBy(): ?string
+    {
+        return $this->sharedBy;
+    }
+
+    public function getSharedByDisplayName(): ?string
+    {
+        return $this->sharedByDisplayName;
+    }
+
     /**
      * @return null|string
      */
@@ -327,7 +368,9 @@ public function jsonSerialize(): array
             'rtl' => $this->getRtl(),
             'intro' => $this->getIntro(),
             'fingerprint' => $this->getFingerprint(),
-            'categories' => $this->getCategories()
+            'categories' => $this->getCategories(),
+            'sharedBy' => $this->getSharedBy(),
+            'sharedByDisplayName' => $this->getSharedByDisplayName()
         ];
     }
 
@@ -509,6 +552,25 @@ public function setTitle(string $title = null): self
         return $this;
     }
 
+    public function setSharedBy(string $sharedBy = null): self
+    {
+        if ($this->sharedBy !== $sharedBy) {
+            $this->sharedBy = $sharedBy;
+            $this->markFieldUpdated('sharedBy');
+        }
+
+        return $this;
+    }
+
+    public function setSharedByDisplayName(string $sharedByDisplayName = null): self
+    {
+        if ($this->sharedByDisplayName !== $sharedByDisplayName) {
+            $this->sharedByDisplayName = $sharedByDisplayName;
+        }
+
+        return $this;
+    }
+
     public function setUnread(bool $unread): self
     {
         if ($this->unread !== $unread) {
diff --git a/lib/Migration/Version150400Date20210318215425.php b/lib/Migration/Version150400Date20210318215425.php
new file mode 100644
index 0000000000..dbe5618bd5
--- /dev/null
+++ b/lib/Migration/Version150400Date20210318215425.php
@@ -0,0 +1,53 @@
+<?php
+
+declare(strict_types=1);
+
+namespace OCA\News\Migration;
+
+use Closure;
+use OCP\DB\ISchemaWrapper;
+use OCP\Migration\IOutput;
+use OCP\Migration\SimpleMigrationStep;
+
+/**
+ * Auto-generated migration step: Please modify to your needs!
+ */
+class Version150400Date20210318215425 extends SimpleMigrationStep {
+
+    /**
+     * @param IOutput $output
+     * @param Closure $schemaClosure The `\Closure` returns a `ISchemaWrapper`
+     * @param array $options
+     */
+    public function preSchemaChange(IOutput $output, Closure $schemaClosure, array $options): void {
+    }
+
+    /**
+     * @param IOutput $output
+     * @param Closure $schemaClosure The `\Closure` returns a `ISchemaWrapper`
+     * @param array $options
+     * @return null|ISchemaWrapper
+     */
+    public function changeSchema(IOutput $output, Closure $schemaClosure, array $options): ?ISchemaWrapper {
+        /** @var ISchemaWrapper $schema */
+        $schema = $schemaClosure();
+
+        if ($schema->hasTable('news_items')) {
+            $table = $schema->getTable('news_items');
+            $table->addColumn('shared_by', 'string', [
+                'notnull' => false,
+                'length' => 64
+            ]);
+        }
+
+        return $schema;
+    }
+
+    /**
+     * @param IOutput $output
+     * @param Closure $schemaClosure The `\Closure` returns a `ISchemaWrapper`
+     * @param array $options
+     */
+    public function postSchemaChange(IOutput $output, Closure $schemaClosure, array $options): void {
+    }
+}
diff --git a/lib/Service/ShareService.php b/lib/Service/ShareService.php
new file mode 100644
index 0000000000..17db4e53bb
--- /dev/null
+++ b/lib/Service/ShareService.php
@@ -0,0 +1,163 @@
+<?php
+/**
+ * Nextcloud - News
+ *
+ * This file is licensed under the Affero General Public License version 3 or
+ * later. See the COPYING file.
+ *
+ * @author    Marco Nassabain <marco.nassabain@hotmail.com>
+ */
+
+namespace OCA\News\Service;
+
+use \OCA\News\Db\Item;
+use \OCA\News\Db\Feed;
+
+use \Psr\Log\LoggerInterface;
+use OCP\IURLGenerator;
+use OCP\IUserManager;
+use \OCP\IL10N;
+
+use OCA\News\Service\Exceptions\ServiceNotFoundException;
+use OCP\AppFramework\Db\DoesNotExistException;
+
+/**
+ * Class ShareService
+ *
+ * @package OCA\News\Service
+ */
+class ShareService
+{
+    /**
+     * Items service.
+     *
+     * @var ItemServiceV2
+     */
+    protected $itemService;
+
+    /**
+     * Feeds service.
+     *
+     * @var FeedServiceV2
+     */
+    protected $feedService;
+
+    /**
+     * @var LoggerInterface
+     */
+    protected $logger;
+
+    /**
+     * @var IURLGenerator
+     */
+    private $urlGenerator;
+
+    /**
+     * @var IUserManager
+     */
+    private $userManager;
+
+    /**
+     * @var IL10N
+     */
+    private $l10n;
+
+    /**
+     * ShareService constructor
+     *
+     * @param FeedServiceV2   $feedService  Service for feeds
+     * @param ItemServiceV2   $itemService  Service to manage items
+     * @param IURLGenerator   $urlGenerator URL Generator
+     * @param IUserManager    $userManager  User Manager
+     * @param IL10N           $l10n         Localization interface
+     * @param LoggerInterface $logger       Logger
+     */
+    public function __construct(
+        FeedServiceV2 $feedService,
+        ItemServiceV2 $itemService,
+        IURLGenerator $urlGenerator,
+        IUserManager $userManager,
+        IL10N $l10n,
+        LoggerInterface $logger
+    ) {
+        $this->itemService  = $itemService;
+        $this->feedService  = $feedService;
+        $this->urlGenerator = $urlGenerator;
+        $this->userManager  = $userManager;
+        $this->l10n         = $l10n;
+        $this->logger       = $logger;
+    }
+
+    /**
+     * Share an item with a user
+     *
+     * @param string $userId           ID of user sharing the item
+     * @param int    $itemId           Item ID
+     * @param string $shareRecipientId ID of user to share with
+     *
+     * Sharing by copying - the item is duplicated, and the 'sharedBy'
+     * field is filled accordingly.
+     * The item is then placed in a dummy feed reserved for items
+     * shared with the user
+     *
+     * @return Item Shared item
+     * @throws ServiceNotFoundException|ServiceConflictException
+     */
+    public function shareItemWithUser(string $userId, int $itemId, string $shareRecipientId)
+    {
+        // Find item to share
+        $item = $this->itemService->find($userId, $itemId);
+
+        // Duplicate item & initialize fields
+        $sharedItem = clone $item;
+        $sharedItem->setId(null);
+        $sharedItem->setUnread(true);
+        $sharedItem->setStarred(false);
+        $sharedItem->setSharedBy($userId);
+
+        // Get 'shared with me' dummy feed
+        $feedUrl = $this->urlGenerator->getBaseUrl() . '/news/sharedwithme';
+        $feed = $this->feedService->findByUrl($shareRecipientId, $feedUrl);
+        if (is_null($feed)) {
+            $feed = new Feed();
+            $feed->setUserId($shareRecipientId)
+                 ->setUrlHash(md5($feedUrl))
+                 ->setLink($feedUrl)
+                 ->setUrl($feedUrl)
+                 ->setTitle($this->l10n->t('Shared with me'))
+                 ->setAdded(time())
+                 ->setFolderId(null)
+                 ->setPreventUpdate(true);
+
+            $feed = $this->feedService->insert($feed);
+        }
+
+        $sharedItem->setFeedId($feed->getId());
+
+        return $this->itemService->insertOrUpdate($sharedItem);
+    }
+
+    /**
+     * Map sharers display names to shared items.
+     *
+     * Loops through an array of news items. For all shared items, the function
+     * fetches the sharers display name and adds it into the item.
+     *
+     * @param Item[]  Array containing items that are shared or not
+     * @return Item[]
+     */
+    public function mapSharedByDisplayNames(array $items): array
+    {
+        foreach ($items as $item) {
+            $sharedBy = $item->getSharedBy();
+            if (!is_null($sharedBy)) {
+                $user = $this->userManager->get($sharedBy);
+                if (!is_null($user)) {
+                    $item->setSharedByDisplayName($user->getDisplayName());
+                }
+            }
+        }
+
+        return $items;
+    }
+}
diff --git a/tests/Unit/Controller/ItemControllerTest.php b/tests/Unit/Controller/ItemControllerTest.php
index c64cd93300..33488a338e 100644
--- a/tests/Unit/Controller/ItemControllerTest.php
+++ b/tests/Unit/Controller/ItemControllerTest.php
@@ -16,6 +16,7 @@
 use OCA\News\Controller\ItemController;
 use OCA\News\Service\FeedServiceV2;
 use OCA\News\Service\ItemServiceV2;
+use OCA\News\Service\ShareService;
 use \OCP\AppFramework\Http;
 
 use \OCA\News\Db\Item;
@@ -46,6 +47,10 @@ class ItemControllerTest extends TestCase
      * @var \PHPUnit\Framework\MockObject\MockObject|FeedServiceV2
      */
     private $feedService;
+    /**
+     * @var \PHPUnit\Framework\MockObject\MockObject|ShareService
+     */
+    private $shareService;
     /**
      * @var \PHPUnit\Framework\MockObject\MockObject|IRequest
      */
@@ -79,6 +84,10 @@ public function setUp(): void
         $this->getMockBuilder(FeedServiceV2::class)
             ->disableOriginalConstructor()
             ->getMock();
+        $this->shareService =
+        $this->getMockBuilder(ShareService::class)
+            ->disableOriginalConstructor()
+            ->getMock();
         $this->request = $this->getMockBuilder(IRequest::class)
             ->disableOriginalConstructor()
             ->getMock();
@@ -95,6 +104,7 @@ public function setUp(): void
             $this->request,
             $this->feedService,
             $this->itemService,
+            $this->shareService,
             $this->settings,
             $this->userSession
         );
@@ -128,6 +138,33 @@ public function testReadDoesNotExist()
     }
 
 
+    public function testShare()
+    {
+        $this->shareService->expects($this->once())
+            ->method('shareItemWithUser')
+            ->with('user', 4, 'test');
+
+        $this->controller->share(4, 'test');
+    }
+
+
+    public function testShareDoesNotExist()
+    {
+        $msg = 'hi';
+
+        $this->shareService->expects($this->once())
+            ->method('shareItemWithUser')
+            ->with('user', 4, 'test')
+            ->will($this->throwException(new ServiceNotFoundException($msg)));
+
+        $response = $this->controller->share(4, 'test');
+        $params = json_decode($response->render(), true);
+
+        $this->assertEquals($response->getStatus(), Http::STATUS_NOT_FOUND);
+        $this->assertEquals($msg, $params['message']);
+    }
+
+
     public function testReadMultiple()
     {
         $this->itemService->expects($this->exactly(2))
@@ -256,6 +293,11 @@ public function testIndexForFeed()
             ->with('user', 2, 3, 0, false, false, [])
             ->will($this->returnValue($result['items']));
 
+        $this->shareService->expects($this->once())
+            ->method('mapSharedByDisplayNames')
+            ->with($result['items'])
+            ->will($this->returnValue($result['items']));
+
         $response = $this->controller->index(ListType::FEED, 2, 3);
         $this->assertEquals($result, $response);
     }
@@ -293,6 +335,11 @@ public function testIndexForFolder()
             ->with('user', 2, 3, 0, false, false, [])
             ->will($this->returnValue($result['items']));
 
+        $this->shareService->expects($this->once())
+            ->method('mapSharedByDisplayNames')
+            ->with($result['items'])
+            ->will($this->returnValue($result['items']));
+
         $response = $this->controller->index(ListType::FOLDER, 2, 3);
         $this->assertEquals($result, $response);
     }
@@ -330,6 +377,11 @@ public function testIndexForOther()
             ->with('user', 2, 3, 0, false, [])
             ->will($this->returnValue($result['items']));
 
+        $this->shareService->expects($this->once())
+            ->method('mapSharedByDisplayNames')
+            ->with($result['items'])
+            ->will($this->returnValue($result['items']));
+
         $response = $this->controller->index(ListType::STARRED, 2, 3);
         $this->assertEquals($result, $response);
     }
@@ -367,6 +419,11 @@ public function testIndexSearchFeed()
             ->with('user', 2, 3, 0, false, false, ['test', 'search'])
             ->will($this->returnValue($result['items']));
 
+        $this->shareService->expects($this->once())
+            ->method('mapSharedByDisplayNames')
+            ->with($result['items'])
+            ->will($this->returnValue($result['items']));
+
         $response = $this->controller->index(ListType::FEED, 2, 3, 0, null, null, 'test%20%20search%20');
         $this->assertEquals($result, $response);
     }
@@ -383,6 +440,11 @@ public function testItemsOffsetNotZero()
             ->with('user', 2, 3, 10, false, true)
             ->will($this->returnValue($result['items']));
 
+        $this->shareService->expects($this->once())
+            ->method('mapSharedByDisplayNames')
+            ->with($result['items'])
+            ->will($this->returnValue($result['items']));
+
         $this->feedService->expects($this->never())
             ->method('findAllForUser');
 
@@ -440,6 +502,11 @@ public function testNewItemsFeed()
             ->with('user', 2, 3, false)
             ->will($this->returnValue($result['items']));
 
+        $this->shareService->expects($this->once())
+            ->method('mapSharedByDisplayNames')
+            ->with($result['items'])
+            ->will($this->returnValue($result['items']));
+
         $response = $this->controller->newItems(ListType::FEED, 2, 3);
         $this->assertEquals($result, $response);
     }
@@ -480,6 +547,11 @@ public function testNewItemsFolder()
             ->with('user', 2, 3, false)
             ->will($this->returnValue($result['items']));
 
+        $this->shareService->expects($this->once())
+            ->method('mapSharedByDisplayNames')
+            ->with($result['items'])
+            ->will($this->returnValue($result['items']));
+
         $response = $this->controller->newItems(ListType::FOLDER, 2, 3);
         $this->assertEquals($result, $response);
     }
@@ -520,6 +592,11 @@ public function testNewItemsOther()
             ->with('user', 6, 3)
             ->will($this->returnValue($result['items']));
 
+        $this->shareService->expects($this->once())
+            ->method('mapSharedByDisplayNames')
+            ->with($result['items'])
+            ->will($this->returnValue($result['items']));
+
         $response = $this->controller->newItems(ListType::UNREAD, 2, 3);
         $this->assertEquals($result, $response);
     }
@@ -542,4 +619,4 @@ public function testGetNewItemsNoNewestItemsId()
     }
 
 
-}
\ No newline at end of file
+}
diff --git a/tests/Unit/Db/ItemTest.php b/tests/Unit/Db/ItemTest.php
index 4f9de59d3a..68b7b5ab8e 100644
--- a/tests/Unit/Db/ItemTest.php
+++ b/tests/Unit/Db/ItemTest.php
@@ -200,6 +200,8 @@ public function testJSONSerialize()
         $item->setStarred(true);
         $item->setLastModified(321);
         $item->setCategories(['food']);
+        $item->setSharedBy('jack');
+        $item->setSharedByDisplayName('Jack');
 
         $this->assertEquals(
             [
@@ -223,7 +225,9 @@ public function testJSONSerialize()
             'rtl' => true,
             'intro' => 'this is a test',
             'fingerprint' => 'fingerprint',
-            'categories' => ['food']
+            'categories' => ['food'],
+            'sharedBy' => 'jack',
+            'sharedByDisplayName' => 'Jack'
             ], $item->jsonSerialize()
         );
     }
@@ -448,4 +452,19 @@ public function testSetCategoriesJson()
         $this->assertEquals(json_encode(['podcast', 'blog']), $item->getCategoriesJson());
         $this->assertArrayHasKey('categoriesJson', $item->getUpdatedFields());
     }
+
+    public function testSetSharedBy()
+    {
+        $item = new Item();
+        $item->setSharedBy('Hector');
+        $this->assertEquals('Hector', $item->getSharedBy());
+        $this->assertArrayHasKey('sharedBy', $item->getUpdatedFields());
+    }
+
+    public function testSetSharedByDisplayName()
+    {
+        $item = new Item();
+        $item->setSharedByDisplayName('Hector');
+        $this->assertEquals('Hector', $item->getSharedByDisplayName());
+    }
 }
diff --git a/tests/Unit/Service/ShareServiceTest.php b/tests/Unit/Service/ShareServiceTest.php
new file mode 100644
index 0000000000..d7c26a9181
--- /dev/null
+++ b/tests/Unit/Service/ShareServiceTest.php
@@ -0,0 +1,291 @@
+<?php
+/**
+ * Nextcloud - News
+ *
+ * This file is licensed under the Affero General Public License version 3 or
+ * later. See the COPYING file.
+ *
+ * @author    Marco Nassabain <marco.nassabain@hotmail.com>
+ */
+
+
+namespace OCA\News\Tests\Unit\Service;
+
+use FeedIo\Explorer;
+use FeedIo\Reader\ReadErrorException;
+
+use OC\L10N\L10N;
+use OCA\News\Service\Exceptions\ServiceConflictException;
+use OCA\News\Service\Exceptions\ServiceNotFoundException;
+use OCP\AppFramework\Db\DoesNotExistException;
+use OCA\News\Service\FeedServiceV2;
+use OCA\News\Service\ItemServiceV2;
+use OCA\News\Service\ShareService;
+use OCA\News\Utility\Time;
+
+use OCA\News\Db\Feed;
+use OCA\News\Db\Item;
+
+use OCP\IURLGenerator;
+use OCP\IUserManager;
+use OCP\IConfig;
+use OCP\IL10N;
+use OCP\IUser;
+
+use PHPUnit\Framework\MockObject\MockObject;
+use PHPUnit\Framework\TestCase;
+use Psr\Log\LoggerInterface;
+
+
+class ShareServiceTest extends TestCase
+{
+    /**
+     * @var MockObject|ItemServiceV2
+     */
+    private $itemService;
+
+    /**
+     * @var MockObject|FeedServiceV2
+     */
+    private $feedService;
+
+    /**
+     * @var MockObject|IURLGenerator
+     */
+    private $urlGenerator;
+
+    /**
+     * @var MockObject|IUserManager
+     */
+    private $userManager;
+
+    /**
+     * @var MockObject|IL10N
+     */
+    private $l10n;
+
+    /**
+     * @var MockObject|LoggerInterface
+     */
+    private $logger;
+
+    /** @var ShareService */
+    private $class;
+
+    /**
+     * @var string
+     */
+    private $uid;
+
+    /**
+     * @var string
+     */
+    private $recipient;
+
+    protected function setUp(): void
+    {
+        $this->logger = $this->getMockBuilder(LoggerInterface::class)
+            ->disableOriginalConstructor()
+            ->getMock();
+        $this->itemService = $this
+            ->getMockBuilder(ItemServiceV2::class)
+            ->disableOriginalConstructor()
+            ->getMock();
+        $this->feedService = $this
+            ->getMockBuilder(FeedServiceV2::class)
+            ->disableOriginalConstructor()
+            ->getMock();
+        $this->urlGenerator = $this
+            ->getMockBuilder(IURLGenerator::class)
+            ->disableOriginalConstructor()
+            ->getMock();
+        $this->userManager = $this
+            ->getMockBuilder(IUserManager::class)
+            ->disableOriginalConstructor()
+            ->getMock();
+        $this->l10n = $this->getMockBuilder(IL10N::class)
+            ->disableOriginalConstructor()
+            ->getMock();
+
+        $this->time = 333333;
+
+        $this->class = new ShareService(
+            $this->feedService,
+            $this->itemService,
+            $this->urlGenerator,
+            $this->userManager,
+            $this->l10n,
+            $this->logger
+        );
+
+        $this->uid = 'sender';
+        $this->recipient = 'recipient';
+    }
+
+    public function testShareItemWithUser()
+    {
+        $feedUrl = 'http://serverurl/news/sharedwithme';
+        $itemId = 3;
+
+        // Item to be shared
+        $item = new Item();
+        $item->setGuid('_guid_')
+            ->setGuidHash(md5('_guid_'))
+            ->setUrl('_url_')
+            ->setTitle('_title_')
+            ->setAuthor('_author_')
+            ->setUnread(0)
+            ->setStarred(1)
+            ->setFeedId(10);
+
+        // Shared item
+        $sharedItem = clone $item;
+        $sharedItem->setUnread(1)       // A newly shared item is unread, ...
+            ->setStarred(0)             // ... not starred, ...
+            ->setFeedId(100)            // ... placed in the 'Shared with me' feed, ...
+            ->setSharedBy($this->uid);  // ... and contains the senders user ID
+
+        // Dummy feed 'Shared with me'
+        $feed = new Feed();
+        $feed->setId(100);
+        $feed->setUserId($this->recipient)
+            ->setUrl($feedUrl)
+            ->setLink($feedUrl)
+            ->setTitle('Shared with me')
+            ->setAdded($this->time)
+            ->setFolderId(null)
+            ->setPreventUpdate(true);
+
+
+        $this->itemService->expects($this->once())
+            ->method('find')
+            ->with($this->uid, $itemId)
+            ->will($this->returnValue($item));
+
+        $this->urlGenerator->expects($this->once())
+            ->method('getBaseUrl')
+            ->will($this->returnValue('http://serverurl'));
+
+        $this->feedService->expects($this->once())
+            ->method('findByUrl')
+            ->with($this->recipient, $feedUrl)
+            ->will($this->returnValue($feed));
+
+        // Here we test if the setters worked properly using 'with()'
+        $this->itemService->expects($this->once())
+            ->method('insertOrUpdate')
+            ->with($sharedItem)
+            ->will($this->returnValue($sharedItem));
+
+
+        $this->class->shareItemWithUser($this->uid, $itemId, $this->recipient);
+    }
+
+    public function testShareItemWithUserCreatesOwnFeedWhenNotFound()
+    {
+        $feedUrl = 'http://serverurl/news/sharedwithme';
+        $itemId = 3;
+
+        // Item to be shared
+        $item = new Item();
+        $item->setGuid('_guid_')
+            ->setGuidHash(md5('_guid_'))
+            ->setUrl('_url_')
+            ->setTitle('_title_')
+            ->setAuthor('_author_')
+            ->setUnread(0)
+            ->setStarred(1)
+            ->setFeedId(10);
+
+        // Shared item
+        $sharedItem = clone $item;
+        $sharedItem->setUnread(1)       // A newly shared item is unread, ...
+            ->setStarred(0)             // ... not starred, ...
+            ->setFeedId(100)            // ... placed in the 'Shared with me' feed, ...
+            ->setSharedBy($this->uid);  // ... and contains the senders user ID
+
+        // Dummy feed 'Shared with me'
+        $feed = new Feed();
+        $feed->setId(100);
+        $feed->setUserId($this->recipient)
+            ->setUrl($feedUrl)
+            ->setLink($feedUrl)
+            ->setTitle('Shared with me')
+            ->setAdded($this->time)
+            ->setFolderId(null)
+            ->setPreventUpdate(true);
+
+
+        $this->itemService->expects($this->once())
+            ->method('find')
+            ->with($this->uid, $itemId)
+            ->will($this->returnValue($item));
+
+        $this->urlGenerator->expects($this->once())
+            ->method('getBaseUrl')
+            ->will($this->returnValue('http://serverurl'));
+
+        $this->feedService->expects($this->once())
+            ->method('findByUrl')
+            ->with($this->recipient, $feedUrl)
+            ->will($this->returnValue(null));
+
+        $this->l10n->expects($this->once())
+            ->method('t')
+            ->with('Shared with me')
+            ->will($this->returnValue('Shared with me'));
+
+        $this->feedService->expects($this->once())
+            ->method('insert')
+            ->will($this->returnValue($feed));
+
+        // Here we test if the setters worked properly using 'with()'
+        $this->itemService->expects($this->once())
+            ->method('insertOrUpdate')
+            ->with($sharedItem)
+            ->will($this->returnValue($sharedItem));
+
+
+        $this->class->shareItemWithUser($this->uid, $itemId, $this->recipient);
+    }
+
+
+    public function testShareItemWithUserItemDoesNotExist()
+    {
+        $this->expectException(ServiceNotFoundException::class);
+        $this->itemService->expects($this->once())
+            ->method('find')
+            ->will($this->throwException(new ServiceNotFoundException('')));
+
+        $this->class->shareItemWithUser('sender', 1, 'recipient');
+    }
+
+
+    public function testMapSharedByDisplayNames()
+    {
+        $item1 = new Item();
+        $item1->setTitle('Item 1')
+              ->setSharedBy('sender');
+        $item2 = new Item();
+        $item2->setTitle('Item 2')
+              ->setSharedBy(null);
+
+        $items = [$item1, $item2];
+        $user = $this->getMockBuilder(IUser::class)
+                     ->getMock();
+
+        $this->userManager->expects($this->once())
+            ->method('get')
+            ->with('sender')
+            ->will($this->returnValue($user));
+
+        $user->expects($this->once())
+            ->method('getDisplayName')
+            ->will($this->returnValue('Mr. Sender'));
+
+        $result = $this->class->mapSharedByDisplayNames($items);
+
+        $this->assertEquals('Mr. Sender', $result[0]->getSharedByDisplayName());
+        $this->assertEquals(null, $result[1]->getSharedByDisplayName());
+    }
+}