diff --git a/apps/files_sharing/tests/SharesUpdatedListenerTest.php b/apps/files_sharing/tests/SharesUpdatedListenerTest.php
new file mode 100644
index 00000000000..3e3211dae36
--- /dev/null
+++ b/apps/files_sharing/tests/SharesUpdatedListenerTest.php
@@ -0,0 +1,136 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+namespace OCA\Files_Sharing\Tests;
+
+use OCA\Files_Sharing\Config\ConfigLexicon;
+use OCA\Files_Sharing\Event\UserShareAccessUpdatedEvent;
+use OCA\Files_Sharing\Listener\SharesUpdatedListener;
+use OCA\Files_Sharing\ShareRecipientUpdater;
+use OCP\Config\IUserConfig;
+use OCP\IAppConfig;
+use OCP\IUser;
+use OCP\Share\Events\BeforeShareDeletedEvent;
+use OCP\Share\Events\ShareCreatedEvent;
+use OCP\Share\IManager;
+use OCP\Share\IShare;
+use PHPUnit\Framework\MockObject\MockObject;
+use Test\Mock\Config\MockAppConfig;
+use Test\Mock\Config\MockUserConfig;
+use Test\Traits\UserTrait;
+
+class SharesUpdatedListenerTest extends \Test\TestCase {
+	use UserTrait;
+
+	private SharesUpdatedListener $sharesUpdatedListener;
+	private ShareRecipientUpdater&MockObject $shareRecipientUpdater;
+	private IManager&MockObject $manager;
+	private IUserConfig $userConfig;
+	private IAppConfig $appConfig;
+
+	protected function setUp(): void {
+		parent::setUp();
+
+		$this->shareRecipientUpdater = $this->createMock(ShareRecipientUpdater::class);
+		$this->manager = $this->createMock(IManager::class);
+		$this->appConfig = new MockAppConfig([
+			ConfigLexicon::UPDATE_ALL_CUTOFF => -1,
+			ConfigLexicon::UPDATE_SINGLE_CUTOFF => -1,
+		]);
+		$this->userConfig = new MockUserConfig();
+		$this->sharesUpdatedListener = new SharesUpdatedListener(
+			$this->manager,
+			$this->shareRecipientUpdater,
+			$this->userConfig,
+			$this->appConfig,
+		);
+	}
+
+	public function testShareAdded() {
+		$share = $this->createMock(IShare::class);
+		$user1 = $this->createUser('user1', '');
+		$user2 = $this->createUser('user2', '');
+
+		$this->manager->method('getUsersForShare')
+			->willReturn([$user1, $user2]);
+
+		$event = new ShareCreatedEvent($share);
+
+		$this->shareRecipientUpdater
+			->expects($this->exactly(2))
+			->method('updateForShare')
+			->willReturnCallback(function (IUser $user, IShare $eventShare) use ($user1, $user2, $share) {
+				$this->assertContains($user, [$user1, $user2]);
+				$this->assertEquals($share, $eventShare);
+			});
+
+		$this->sharesUpdatedListener->handle($event);
+	}
+
+	public function testShareAddedFilterOwner() {
+		$share = $this->createMock(IShare::class);
+		$user1 = $this->createUser('user1', '');
+		$user2 = $this->createUser('user2', '');
+		$share->method('getSharedBy')
+			->willReturn($user1->getUID());
+
+		$this->manager->method('getUsersForShare')
+			->willReturn([$user1, $user2]);
+
+		$event = new ShareCreatedEvent($share);
+
+		$this->shareRecipientUpdater
+			->expects($this->exactly(1))
+			->method('updateForShare')
+			->willReturnCallback(function (IUser $user, IShare $eventShare) use ($user2, $share) {
+				$this->assertEquals($user, $user2);
+				$this->assertEquals($share, $eventShare);
+			});
+
+		$this->sharesUpdatedListener->handle($event);
+	}
+
+	public function testShareAccessUpdated() {
+		$user1 = $this->createUser('user1', '');
+		$user2 = $this->createUser('user2', '');
+
+		$event = new UserShareAccessUpdatedEvent([$user1, $user2]);
+
+		$this->shareRecipientUpdater
+			->expects($this->exactly(2))
+			->method('updateForUser')
+			->willReturnCallback(function (IUser $user, bool $verifyMountPoints = true, array $ignoreShares = []) use ($user1, $user2) {
+				$this->assertContains($user, [$user1, $user2]);
+				$this->assertEquals(true, $verifyMountPoints);
+				$this->assertEquals([], $ignoreShares);
+			});
+
+		$this->sharesUpdatedListener->handle($event);
+	}
+
+	public function testShareDeleted() {
+		$share = $this->createMock(IShare::class);
+		$user1 = $this->createUser('user1', '');
+		$user2 = $this->createUser('user2', '');
+
+		$this->manager->method('getUsersForShare')
+			->willReturn([$user1, $user2]);
+
+		$event = new BeforeShareDeletedEvent($share);
+
+		$this->shareRecipientUpdater
+			->expects($this->exactly(2))
+			->method('updateForUser')
+			->willReturnCallback(function (IUser $user, bool $verifyMountPoints = true, array $ignoreShares = []) use ($user1, $user2, $share) {
+				$this->assertContains($user, [$user1, $user2]);
+				$this->assertEquals(false, $verifyMountPoints);
+				$this->assertEquals([$share], $ignoreShares);
+			});
+
+		$this->sharesUpdatedListener->handle($event);
+	}
+}