diff --git a/build/psalm-baseline.xml b/build/psalm-baseline.xml
index 0b8a0c0b8a3..b16a8d1e342 100644
--- a/build/psalm-baseline.xml
+++ b/build/psalm-baseline.xml
@@ -4306,4 +4306,13 @@
       <code><![CDATA[getAppValue]]></code>
     </DeprecatedMethod>
   </file>
+  <file src="tests/lib/TestCase.php">
+    <DeprecatedMethod>
+      <code><![CDATA[$container]]></code>
+    </DeprecatedMethod>
+    <InternalMethod>
+      <code><![CDATA[lockFile]]></code>
+      <code><![CDATA[unlockFile]]></code>
+    </InternalMethod>
+  </file>
 </files>
diff --git a/lib/public/Comments/ICommentsManager.php b/lib/public/Comments/ICommentsManager.php
index 1be8c73a336..651734ea1ff 100644
--- a/lib/public/Comments/ICommentsManager.php
+++ b/lib/public/Comments/ICommentsManager.php
@@ -438,6 +438,7 @@ interface ICommentsManager {
 	 * to consumers of the comments infrastructure
 	 *
 	 * @param \Closure $closure
+	 * @return void
 	 * @since 11.0.0
 	 */
 	public function registerEventHandler(\Closure $closure);
@@ -447,6 +448,7 @@ interface ICommentsManager {
 	 *
 	 * @param string $type
 	 * @param \Closure $closure
+	 * @return void
 	 * @throws \OutOfBoundsException
 	 * @since 11.0.0
 	 *
diff --git a/psalm.xml b/psalm.xml
index f3b66f4f6e4..61fc300f101 100644
--- a/psalm.xml
+++ b/psalm.xml
@@ -54,6 +54,7 @@
 		<directory name="core"/>
 		<directory name="lib"/>
 		<directory name="ocs"/>
+		<directory name="tests/lib/Comments"/>
 		<directory name="ocs-provider"/>
 		<file name="cron.php"/>
 		<file name="index.php"/>
@@ -61,6 +62,7 @@
 		<file name="remote.php"/>
 		<file name="status.php"/>
 		<file name="version.php"/>
+		<file name="tests/lib/TestCase.php"/>
 		<ignoreFiles>
 			<directory name="apps/**/composer"/>
 			<directory name="apps/**/tests"/>
@@ -71,6 +73,7 @@
 	</projectFiles>
 	<extraFiles>
 		<directory name="3rdparty"/>
+		<directory name="vendor-bin/phpunit/vendor/phpunit"/>
 	</extraFiles>
 	<stubs>
 		<file name="build/stubs/apcu.php"/>
diff --git a/tests/lib/Comments/CommentTest.php b/tests/lib/Comments/CommentTest.php
index 4a320666c83..670ccc69e12 100644
--- a/tests/lib/Comments/CommentTest.php
+++ b/tests/lib/Comments/CommentTest.php
@@ -11,6 +11,7 @@ use OC\Comments\Comment;
 use OCP\Comments\IComment;
 use OCP\Comments\IllegalIDChangeException;
 use OCP\Comments\MessageTooLongException;
+use PHPUnit\Framework\Attributes\DataProvider;
 use Test\TestCase;
 
 class CommentTest extends TestCase {
@@ -96,7 +97,7 @@ class CommentTest extends TestCase {
 		];
 	}
 
-	#[\PHPUnit\Framework\Attributes\DataProvider('simpleSetterProvider')]
+	#[DataProvider(methodName: 'simpleSetterProvider')]
 	public function testSimpleSetterInvalidInput($field, $input): void {
 		$this->expectException(\InvalidArgumentException::class);
 
@@ -119,7 +120,7 @@ class CommentTest extends TestCase {
 		];
 	}
 
-	#[\PHPUnit\Framework\Attributes\DataProvider('roleSetterProvider')]
+	#[DataProvider(methodName: 'roleSetterProvider')]
 	public function testSetRoleInvalidInput($role, $type, $id): void {
 		$this->expectException(\InvalidArgumentException::class);
 
@@ -204,13 +205,7 @@ class CommentTest extends TestCase {
 		];
 	}
 
-	/**
-	 *
-	 * @param string $message
-	 * @param array $expectedMentions
-	 * @param ?string $author
-	 */
-	#[\PHPUnit\Framework\Attributes\DataProvider('mentionsProvider')]
+	#[DataProvider(methodName: 'mentionsProvider')]
 	public function testMentions(string $message, array $expectedMentions, ?string $author = null): void {
 		$comment = new Comment();
 		$comment->setMessage($message);
diff --git a/tests/lib/Comments/FakeManager.php b/tests/lib/Comments/FakeManager.php
index ebee6519992..518e4801d0b 100644
--- a/tests/lib/Comments/FakeManager.php
+++ b/tests/lib/Comments/FakeManager.php
@@ -16,10 +16,12 @@ use OCP\IUser;
  * Class FakeManager
  */
 class FakeManager implements ICommentsManager {
-	public function get($id) {
+	public function get($id): IComment {
+		throw new \Exception('Not implemented');
 	}
 
-	public function getTree($id, $limit = 0, $offset = 0) {
+	public function getTree($id, $limit = 0, $offset = 0): array {
+		return ['comment' => new Comment(), 'replies' => []];
 	}
 
 	public function getForObject(
@@ -28,7 +30,8 @@ class FakeManager implements ICommentsManager {
 		$limit = 0,
 		$offset = 0,
 		?\DateTime $notOlderThan = null,
-	) {
+	): array {
+		return [];
 	}
 
 	public function getForObjectSince(
@@ -57,6 +60,7 @@ class FakeManager implements ICommentsManager {
 	}
 
 	public function getNumberOfCommentsForObject($objectType, $objectId, ?\DateTime $notOlderThan = null, $verb = ''): int {
+		return 0;
 	}
 
 	public function getNumberOfCommentsForObjects(string $objectType, array $objectIds, ?\DateTime $notOlderThan = null, string $verb = ''): array {
@@ -67,10 +71,12 @@ class FakeManager implements ICommentsManager {
 		return [];
 	}
 
-	public function create($actorType, $actorId, $objectType, $objectId) {
+	public function create($actorType, $actorId, $objectType, $objectId): IComment {
+		return new Comment();
 	}
 
-	public function delete($id) {
+	public function delete($id): bool {
+		return false;
 	}
 
 	public function getReactionComment(int $parentId, string $actorType, string $actorId, string $reaction): IComment {
@@ -89,47 +95,52 @@ class FakeManager implements ICommentsManager {
 		return false;
 	}
 
-	public function save(IComment $comment) {
+	public function save(IComment $comment): bool {
+		return false;
 	}
 
-	public function deleteReferencesOfActor($actorType, $actorId) {
+	public function deleteReferencesOfActor($actorType, $actorId): bool {
+		return false;
 	}
 
-	public function deleteCommentsAtObject($objectType, $objectId) {
+	public function deleteCommentsAtObject($objectType, $objectId): bool {
+		return false;
 	}
 
-	public function setReadMark($objectType, $objectId, \DateTime $dateTime, IUser $user) {
+	public function setReadMark($objectType, $objectId, \DateTime $dateTime, IUser $user): bool {
+		return false;
 	}
 
-	public function getReadMark($objectType, $objectId, IUser $user) {
+	public function getReadMark($objectType, $objectId, IUser $user): bool {
+		return false;
 	}
 
-	public function deleteReadMarksFromUser(IUser $user) {
+	public function deleteReadMarksFromUser(IUser $user): bool {
+		return false;
 	}
 
-	public function deleteReadMarksOnObject($objectType, $objectId) {
+	public function deleteReadMarksOnObject($objectType, $objectId): bool {
+		return false;
 	}
 
-	public function registerEventHandler(\Closure $closure) {
+	public function registerEventHandler(\Closure $closure): void {
 	}
 
-	public function registerDisplayNameResolver($type, \Closure $closure) {
+	public function registerDisplayNameResolver($type, \Closure $closure): void {
 	}
 
-	public function resolveDisplayName($type, $id) {
+	public function resolveDisplayName($type, $id): string {
+		return '';
 	}
 
-	public function getNumberOfUnreadCommentsForFolder($folderId, IUser $user) {
+	public function getNumberOfUnreadCommentsForFolder($folderId, IUser $user): array {
+		return [];
 	}
 
 	public function getNumberOfUnreadCommentsForObjects(string $objectType, array $objectIds, IUser $user, $verb = ''): array {
 		return [];
 	}
 
-
-	public function getActorsInTree($id) {
-	}
-
 	public function load(): void {
 	}
 
diff --git a/tests/lib/Comments/ManagerTest.php b/tests/lib/Comments/ManagerTest.php
index d88e062a8ec..d0cb1e00fe8 100644
--- a/tests/lib/Comments/ManagerTest.php
+++ b/tests/lib/Comments/ManagerTest.php
@@ -26,18 +26,19 @@ use OCP\IInitialStateService;
 use OCP\IUser;
 use OCP\IUserManager;
 use OCP\Server;
+use PHPUnit\Framework\Attributes\DataProvider;
+use PHPUnit\Framework\Attributes\Group;
+use PHPUnit\Framework\MockObject\MockObject;
 use Psr\Log\LoggerInterface;
 use Test\TestCase;
 
 /**
  * Class ManagerTest
  */
-#[\PHPUnit\Framework\Attributes\Group('DB')]
+#[Group(name: 'DB')]
 class ManagerTest extends TestCase {
-	/** @var IDBConnection */
-	private $connection;
-	/** @var \PHPUnit\Framework\MockObject\MockObject|IRootFolder */
-	private $rootFolder;
+	private IDBConnection $connection;
+	private IRootFolder&MockObject $rootFolder;
 
 	protected function setUp(): void {
 		parent::setUp();
@@ -45,13 +46,15 @@ class ManagerTest extends TestCase {
 		$this->connection = Server::get(IDBConnection::class);
 		$this->rootFolder = $this->createMock(IRootFolder::class);
 
+		/** @psalm-suppress DeprecatedMethod */
 		$sql = $this->connection->getDatabasePlatform()->getTruncateTableSQL('`*PREFIX*comments`');
 		$this->connection->prepare($sql)->execute();
+		/** @psalm-suppress DeprecatedMethod */
 		$sql = $this->connection->getDatabasePlatform()->getTruncateTableSQL('`*PREFIX*reactions`');
 		$this->connection->prepare($sql)->execute();
 	}
 
-	protected function addDatabaseEntry($parentId, $topmostParentId, $creationDT = null, $latestChildDT = null, $objectId = null, $expireDate = null) {
+	protected function addDatabaseEntry(?string $parentId, ?string $topmostParentId, ?\DateTimeInterface $creationDT = null, ?\DateTimeInterface $latestChildDT = null, $objectId = null, ?\DateTimeInterface $expireDate = null): string {
 		$creationDT ??= new \DateTime();
 		$latestChildDT ??= new \DateTime('yesterday');
 		$objectId ??= 'file64';
@@ -77,10 +80,11 @@ class ManagerTest extends TestCase {
 			])
 			->executeStatement();
 
-		return $qb->getLastInsertId();
+		return (string)$qb->getLastInsertId();
 	}
 
-	protected function getManager() {
+	protected function getManager(): Manager {
+		/** @psalm-suppress DeprecatedInterface No way around at the moment */
 		return new Manager(
 			$this->connection,
 			$this->createMock(LoggerInterface::class),
@@ -115,7 +119,7 @@ class ManagerTest extends TestCase {
 		$creationDT = new \DateTime('yesterday');
 		$latestChildDT = new \DateTime();
 
-		$qb = Server::get(IDBConnection::class)->getQueryBuilder();
+		$qb = $this->connection->getQueryBuilder();
 		$qb
 			->insert('comments')
 			->values([
@@ -155,7 +159,6 @@ class ManagerTest extends TestCase {
 		$this->assertEquals(['last_edit_actor_id' => 'admin'], $comment->getMetaData());
 	}
 
-
 	public function testGetTreeNotFound(): void {
 		$this->expectException(NotFoundException::class);
 
@@ -163,7 +166,6 @@ class ManagerTest extends TestCase {
 		$manager->getTree('22');
 	}
 
-
 	public function testGetTreeNotFoundInvalidIpnut(): void {
 		$this->expectException(\InvalidArgumentException::class);
 
@@ -172,7 +174,7 @@ class ManagerTest extends TestCase {
 	}
 
 	public function testGetTree(): void {
-		$headId = $this->addDatabaseEntry(0, 0);
+		$headId = $this->addDatabaseEntry('0', '0');
 
 		$this->addDatabaseEntry($headId, $headId, new \DateTime('-3 hours'));
 		$this->addDatabaseEntry($headId, $headId, new \DateTime('-2 hours'));
@@ -184,7 +186,7 @@ class ManagerTest extends TestCase {
 		// Verifying the root comment
 		$this->assertArrayHasKey('comment', $tree);
 		$this->assertInstanceOf(IComment::class, $tree['comment']);
-		$this->assertSame((string)$headId, $tree['comment']->getId());
+		$this->assertSame($headId, $tree['comment']->getId());
 		$this->assertArrayHasKey('replies', $tree);
 		$this->assertCount(3, $tree['replies']);
 
@@ -198,7 +200,7 @@ class ManagerTest extends TestCase {
 	}
 
 	public function testGetTreeNoReplies(): void {
-		$id = $this->addDatabaseEntry(0, 0);
+		$id = $this->addDatabaseEntry('0', '0');
 
 		$manager = $this->getManager();
 		$tree = $manager->getTree($id);
@@ -206,13 +208,13 @@ class ManagerTest extends TestCase {
 		// Verifying the root comment
 		$this->assertArrayHasKey('comment', $tree);
 		$this->assertInstanceOf(IComment::class, $tree['comment']);
-		$this->assertSame((string)$id, $tree['comment']->getId());
+		$this->assertSame($id, $tree['comment']->getId());
 		$this->assertArrayHasKey('replies', $tree);
 		$this->assertCount(0, $tree['replies']);
 	}
 
 	public function testGetTreeWithLimitAndOffset(): void {
-		$headId = $this->addDatabaseEntry(0, 0);
+		$headId = $this->addDatabaseEntry('0', '0');
 
 		$this->addDatabaseEntry($headId, $headId, new \DateTime('-3 hours'));
 		$this->addDatabaseEntry($headId, $headId, new \DateTime('-2 hours'));
@@ -222,19 +224,19 @@ class ManagerTest extends TestCase {
 		$manager = $this->getManager();
 
 		for ($offset = 0; $offset < 3; $offset += 2) {
-			$tree = $manager->getTree((string)$headId, 2, $offset);
+			$tree = $manager->getTree($headId, 2, $offset);
 
 			// Verifying the root comment
 			$this->assertArrayHasKey('comment', $tree);
 			$this->assertInstanceOf(IComment::class, $tree['comment']);
-			$this->assertSame((string)$headId, $tree['comment']->getId());
+			$this->assertSame($headId, $tree['comment']->getId());
 			$this->assertArrayHasKey('replies', $tree);
 			$this->assertCount(2, $tree['replies']);
 
 			// one level deep
 			foreach ($tree['replies'] as $reply) {
 				$this->assertInstanceOf(IComment::class, $reply['comment']);
-				$this->assertSame((string)$idToVerify, $reply['comment']->getId());
+				$this->assertSame((string)$idToVerify, (string)$reply['comment']->getId());
 				$this->assertCount(0, $reply['replies']);
 				$idToVerify--;
 			}
@@ -242,7 +244,7 @@ class ManagerTest extends TestCase {
 	}
 
 	public function testGetForObject(): void {
-		$this->addDatabaseEntry(0, 0);
+		$this->addDatabaseEntry('0', '0');
 
 		$manager = $this->getManager();
 		$comments = $manager->getForObject('files', 'file64');
@@ -254,13 +256,13 @@ class ManagerTest extends TestCase {
 	}
 
 	public function testGetForObjectWithLimitAndOffset(): void {
-		$this->addDatabaseEntry(0, 0, new \DateTime('-6 hours'));
-		$this->addDatabaseEntry(0, 0, new \DateTime('-5 hours'));
-		$this->addDatabaseEntry(1, 1, new \DateTime('-4 hours'));
-		$this->addDatabaseEntry(0, 0, new \DateTime('-3 hours'));
-		$this->addDatabaseEntry(2, 2, new \DateTime('-2 hours'));
-		$this->addDatabaseEntry(2, 2, new \DateTime('-1 hours'));
-		$idToVerify = $this->addDatabaseEntry(3, 1, new \DateTime());
+		$this->addDatabaseEntry('0', '0', new \DateTime('-6 hours'));
+		$this->addDatabaseEntry('0', '0', new \DateTime('-5 hours'));
+		$this->addDatabaseEntry('1', '1', new \DateTime('-4 hours'));
+		$this->addDatabaseEntry('0', '0', new \DateTime('-3 hours'));
+		$this->addDatabaseEntry('2', '2', new \DateTime('-2 hours'));
+		$this->addDatabaseEntry('2', '2', new \DateTime('-1 hours'));
+		$idToVerify = $this->addDatabaseEntry('3', '1', new \DateTime());
 
 		$manager = $this->getManager();
 		$offset = 0;
@@ -279,27 +281,27 @@ class ManagerTest extends TestCase {
 	}
 
 	public function testGetForObjectWithDateTimeConstraint(): void {
-		$this->addDatabaseEntry(0, 0, new \DateTime('-6 hours'));
-		$this->addDatabaseEntry(0, 0, new \DateTime('-5 hours'));
-		$id1 = $this->addDatabaseEntry(0, 0, new \DateTime('-3 hours'));
-		$id2 = $this->addDatabaseEntry(2, 2, new \DateTime('-2 hours'));
+		$this->addDatabaseEntry('0', '0', new \DateTime('-6 hours'));
+		$this->addDatabaseEntry('0', '0', new \DateTime('-5 hours'));
+		$id1 = $this->addDatabaseEntry('0', '0', new \DateTime('-3 hours'));
+		$id2 = $this->addDatabaseEntry('2', '2', new \DateTime('-2 hours'));
 
 		$manager = $this->getManager();
 		$comments = $manager->getForObject('files', 'file64', 0, 0, new \DateTime('-4 hours'));
 
 		$this->assertCount(2, $comments);
-		$this->assertSame((string)$id2, $comments[0]->getId());
-		$this->assertSame((string)$id1, $comments[1]->getId());
+		$this->assertSame($id2, $comments[0]->getId());
+		$this->assertSame($id1, $comments[1]->getId());
 	}
 
 	public function testGetForObjectWithLimitAndOffsetAndDateTimeConstraint(): void {
-		$this->addDatabaseEntry(0, 0, new \DateTime('-7 hours'));
-		$this->addDatabaseEntry(0, 0, new \DateTime('-6 hours'));
-		$this->addDatabaseEntry(1, 1, new \DateTime('-5 hours'));
-		$this->addDatabaseEntry(0, 0, new \DateTime('-3 hours'));
-		$this->addDatabaseEntry(2, 2, new \DateTime('-2 hours'));
-		$this->addDatabaseEntry(2, 2, new \DateTime('-1 hours'));
-		$idToVerify = $this->addDatabaseEntry(3, 1, new \DateTime());
+		$this->addDatabaseEntry('0', '0', new \DateTime('-7 hours'));
+		$this->addDatabaseEntry('0', '0', new \DateTime('-6 hours'));
+		$this->addDatabaseEntry('1', '1', new \DateTime('-5 hours'));
+		$this->addDatabaseEntry('0', '0', new \DateTime('-3 hours'));
+		$this->addDatabaseEntry('2', '2', new \DateTime('-2 hours'));
+		$this->addDatabaseEntry('2', '2', new \DateTime('-1 hours'));
+		$idToVerify = $this->addDatabaseEntry('3', '1', new \DateTime());
 
 		$manager = $this->getManager();
 		$offset = 0;
@@ -320,7 +322,7 @@ class ManagerTest extends TestCase {
 
 	public function testGetNumberOfCommentsForObject(): void {
 		for ($i = 1; $i < 5; $i++) {
-			$this->addDatabaseEntry(0, 0);
+			$this->addDatabaseEntry('0', '0');
 		}
 
 		$manager = $this->getManager();
@@ -351,11 +353,11 @@ class ManagerTest extends TestCase {
 		// 2 comments for 1112 with no read marker
 		// 1 comment for 1113 before read marker
 		// 1 comment for 1114 with no read marker
-		$this->addDatabaseEntry(0, 0, null, null, $fileIds[1]);
+		$this->addDatabaseEntry('0', '0', null, null, $fileIds[1]);
 		for ($i = 0; $i < 4; $i++) {
-			$this->addDatabaseEntry(0, 0, null, null, $fileIds[$i]);
+			$this->addDatabaseEntry('0', '0', null, null, $fileIds[$i]);
 		}
-		$this->addDatabaseEntry(0, 0, (new \DateTime())->modify('-2 days'), null, $fileIds[0]);
+		$this->addDatabaseEntry('0', '0', (new \DateTime())->modify('-2 days'), null, $fileIds[0]);
 		/** @var IUser|\PHPUnit\Framework\MockObject\MockObject $user */
 		$user = $this->createMock(IUser::class);
 		$user->expects($this->any())
@@ -375,24 +377,24 @@ class ManagerTest extends TestCase {
 		], $amount);
 	}
 
-	#[\PHPUnit\Framework\Attributes\DataProvider('dataGetForObjectSince')]
+	#[DataProvider(methodName: 'dataGetForObjectSince')]
 	public function testGetForObjectSince(?int $lastKnown, string $order, int $limit, int $resultFrom, int $resultTo): void {
 		$ids = [];
-		$ids[] = $this->addDatabaseEntry(0, 0);
-		$ids[] = $this->addDatabaseEntry(0, 0);
-		$ids[] = $this->addDatabaseEntry(0, 0);
-		$ids[] = $this->addDatabaseEntry(0, 0);
-		$ids[] = $this->addDatabaseEntry(0, 0);
+		$ids[] = $this->addDatabaseEntry('0', '0');
+		$ids[] = $this->addDatabaseEntry('0', '0');
+		$ids[] = $this->addDatabaseEntry('0', '0');
+		$ids[] = $this->addDatabaseEntry('0', '0');
+		$ids[] = $this->addDatabaseEntry('0', '0');
 
 		$manager = $this->getManager();
-		$comments = $manager->getForObjectSince('files', 'file64', ($lastKnown === null ? 0 : $ids[$lastKnown]), $order, $limit);
+		$comments = $manager->getForObjectSince('files', 'file64', ($lastKnown === null ? 0 : (int)$ids[$lastKnown]), $order, $limit);
 
 		$expected = array_slice($ids, $resultFrom, $resultTo - $resultFrom + 1);
 		if ($order === 'desc') {
 			$expected = array_reverse($expected);
 		}
 
-		$this->assertSame($expected, array_map(static fn (IComment $c): int => (int)$c->getId(), $comments));
+		$this->assertSame($expected, array_map(static fn (IComment $c): string => $c->getId(), $comments));
 	}
 
 	public static function dataGetForObjectSince(): array {
@@ -421,7 +423,7 @@ class ManagerTest extends TestCase {
 		];
 	}
 
-	#[\PHPUnit\Framework\Attributes\DataProvider('invalidCreateArgsProvider')]
+	#[DataProvider(methodName: 'invalidCreateArgsProvider')]
 	public function testCreateCommentInvalidArguments(string|int $aType, string|int $aId, string|int $oType, string|int $oId): void {
 		$this->expectException(\InvalidArgumentException::class);
 
@@ -458,7 +460,7 @@ class ManagerTest extends TestCase {
 		$done = $manager->delete('');
 		$this->assertFalse($done);
 
-		$id = (string)$this->addDatabaseEntry(0, 0);
+		$id = $this->addDatabaseEntry('0', '0');
 		$comment = $manager->get($id);
 		$this->assertInstanceOf(IComment::class, $comment);
 		$done = $manager->delete($id);
@@ -466,7 +468,7 @@ class ManagerTest extends TestCase {
 		$manager->get($id);
 	}
 
-	#[\PHPUnit\Framework\Attributes\DataProvider('providerTestSave')]
+	#[DataProvider(methodName: 'providerTestSave')]
 	public function testSave(string $message, string $actorId, string $verb, ?string $parentId, ?string $id = ''): IComment {
 		$manager = $this->getManager();
 		$comment = new Comment();
@@ -573,7 +575,7 @@ class ManagerTest extends TestCase {
 	}
 
 	public function testSaveAsChild(): void {
-		$id = (string)$this->addDatabaseEntry(0, 0);
+		$id = $this->addDatabaseEntry('0', '0');
 
 		$manager = $this->getManager();
 
@@ -606,7 +608,7 @@ class ManagerTest extends TestCase {
 			];
 	}
 
-	#[\PHPUnit\Framework\Attributes\DataProvider('invalidActorArgsProvider')]
+	#[DataProvider(methodName: 'invalidActorArgsProvider')]
 	public function testDeleteReferencesOfActorInvalidInput(string|int $type, string|int $id): void {
 		$this->expectException(\InvalidArgumentException::class);
 
@@ -616,14 +618,14 @@ class ManagerTest extends TestCase {
 
 	public function testDeleteReferencesOfActor(): void {
 		$ids = [];
-		$ids[] = $this->addDatabaseEntry(0, 0);
-		$ids[] = $this->addDatabaseEntry(0, 0);
-		$ids[] = $this->addDatabaseEntry(0, 0);
+		$ids[] = $this->addDatabaseEntry('0', '0');
+		$ids[] = $this->addDatabaseEntry('0', '0');
+		$ids[] = $this->addDatabaseEntry('0', '0');
 
 		$manager = $this->getManager();
 
 		// just to make sure they are really set, with correct actor data
-		$comment = $manager->get((string)$ids[1]);
+		$comment = $manager->get($ids[1]);
 		$this->assertSame('users', $comment->getActorType());
 		$this->assertSame('alice', $comment->getActorId());
 
@@ -631,7 +633,7 @@ class ManagerTest extends TestCase {
 		$this->assertTrue($wasSuccessful);
 
 		foreach ($ids as $id) {
-			$comment = $manager->get((string)$id);
+			$comment = $manager->get($id);
 			$this->assertSame(ICommentsManager::DELETED_USER, $comment->getActorType());
 			$this->assertSame(ICommentsManager::DELETED_USER, $comment->getActorId());
 		}
@@ -671,7 +673,7 @@ class ManagerTest extends TestCase {
 			];
 	}
 
-	#[\PHPUnit\Framework\Attributes\DataProvider('invalidObjectArgsProvider')]
+	#[DataProvider(methodName: 'invalidObjectArgsProvider')]
 	public function testDeleteCommentsAtObjectInvalidInput(string|int $type, string|int $id): void {
 		$this->expectException(\InvalidArgumentException::class);
 
@@ -681,14 +683,14 @@ class ManagerTest extends TestCase {
 
 	public function testDeleteCommentsAtObject(): void {
 		$ids = [];
-		$ids[] = $this->addDatabaseEntry(0, 0);
-		$ids[] = $this->addDatabaseEntry(0, 0);
-		$ids[] = $this->addDatabaseEntry(0, 0);
+		$ids[] = $this->addDatabaseEntry('0', '0');
+		$ids[] = $this->addDatabaseEntry('0', '0');
+		$ids[] = $this->addDatabaseEntry('0', '0');
 
 		$manager = $this->getManager();
 
 		// just to make sure they are really set, with correct actor data
-		$comment = $manager->get((string)$ids[1]);
+		$comment = $manager->get($ids[1]);
 		$this->assertSame('files', $comment->getObjectType());
 		$this->assertSame('file64', $comment->getObjectId());
 
@@ -698,7 +700,7 @@ class ManagerTest extends TestCase {
 		$verified = 0;
 		foreach ($ids as $id) {
 			try {
-				$manager->get((string)$id);
+				$manager->get($id);
 			} catch (NotFoundException) {
 				$verified++;
 			}
@@ -713,13 +715,14 @@ class ManagerTest extends TestCase {
 
 	public function testDeleteCommentsExpiredAtObjectTypeAndId(): void {
 		$ids = [];
-		$ids[] = $this->addDatabaseEntry(0, 0, null, null, null, new \DateTime('+2 hours'));
-		$ids[] = $this->addDatabaseEntry(0, 0, null, null, null, new \DateTime('+2 hours'));
-		$ids[] = $this->addDatabaseEntry(0, 0, null, null, null, new \DateTime('+2 hours'));
-		$ids[] = $this->addDatabaseEntry(0, 0, null, null, null, new \DateTime('-2 hours'));
-		$ids[] = $this->addDatabaseEntry(0, 0, null, null, null, new \DateTime('-2 hours'));
-		$ids[] = $this->addDatabaseEntry(0, 0, null, null, null, new \DateTime('-2 hours'));
-
+		$ids[] = $this->addDatabaseEntry('0', '0', null, null, null, new \DateTime('+2 hours'));
+		$ids[] = $this->addDatabaseEntry('0', '0', null, null, null, new \DateTime('+2 hours'));
+		$ids[] = $this->addDatabaseEntry('0', '0', null, null, null, new \DateTime('+2 hours'));
+		$ids[] = $this->addDatabaseEntry('0', '0', null, null, null, new \DateTime('-2 hours'));
+		$ids[] = $this->addDatabaseEntry('0', '0', null, null, null, new \DateTime('-2 hours'));
+		$ids[] = $this->addDatabaseEntry('0', '0', null, null, null, new \DateTime('-2 hours'));
+
+		/** @psalm-suppress DeprecatedInterface No way around at the moment */
 		$manager = new Manager(
 			$this->connection,
 			$this->createMock(LoggerInterface::class),
@@ -732,7 +735,7 @@ class ManagerTest extends TestCase {
 		);
 
 		// just to make sure they are really set, with correct actor data
-		$comment = $manager->get((string)$ids[1]);
+		$comment = $manager->get($ids[1]);
 		$this->assertSame('files', $comment->getObjectType());
 		$this->assertSame('file64', $comment->getObjectId());
 
@@ -743,7 +746,7 @@ class ManagerTest extends TestCase {
 		$exists = 0;
 		foreach ($ids as $id) {
 			try {
-				$manager->get((string)$id);
+				$manager->get($id);
 				$exists++;
 			} catch (NotFoundException) {
 				$deleted++;
@@ -760,13 +763,14 @@ class ManagerTest extends TestCase {
 
 	public function testDeleteCommentsExpiredAtObjectType(): void {
 		$ids = [];
-		$ids[] = $this->addDatabaseEntry(0, 0, null, null, 'file1', new \DateTime('-2 hours'));
-		$ids[] = $this->addDatabaseEntry(0, 0, null, null, 'file2', new \DateTime('-2 hours'));
-		$ids[] = $this->addDatabaseEntry(0, 0, null, null, 'file3', new \DateTime('-2 hours'));
-		$ids[] = $this->addDatabaseEntry(0, 0, null, null, 'file3', new \DateTime());
-		$ids[] = $this->addDatabaseEntry(0, 0, null, null, 'file3', new \DateTime());
-		$ids[] = $this->addDatabaseEntry(0, 0, null, null, 'file3', new \DateTime());
-
+		$ids[] = $this->addDatabaseEntry('0', '0', null, null, 'file1', new \DateTime('-2 hours'));
+		$ids[] = $this->addDatabaseEntry('0', '0', null, null, 'file2', new \DateTime('-2 hours'));
+		$ids[] = $this->addDatabaseEntry('0', '0', null, null, 'file3', new \DateTime('-2 hours'));
+		$ids[] = $this->addDatabaseEntry('0', '0', null, null, 'file3', new \DateTime());
+		$ids[] = $this->addDatabaseEntry('0', '0', null, null, 'file3', new \DateTime());
+		$ids[] = $this->addDatabaseEntry('0', '0', null, null, 'file3', new \DateTime());
+
+		/** @psalm-suppress DeprecatedInterface No way around at the moment */
 		$manager = new Manager(
 			$this->connection,
 			$this->createMock(LoggerInterface::class),
@@ -785,7 +789,7 @@ class ManagerTest extends TestCase {
 		$exists = 0;
 		foreach ($ids as $id) {
 			try {
-				$manager->get((string)$id);
+				$manager->get($id);
 				$exists++;
 			} catch (NotFoundException) {
 				$deleted++;
@@ -838,7 +842,6 @@ class ManagerTest extends TestCase {
 	}
 
 	public function testReadMarkDeleteUser(): void {
-		/** @var IUser|\PHPUnit\Framework\MockObject\MockObject $user */
 		$user = $this->createMock(IUser::class);
 		$user->expects($this->any())
 			->method('getUID')
@@ -856,7 +859,6 @@ class ManagerTest extends TestCase {
 	}
 
 	public function testReadMarkDeleteObject(): void {
-		/** @var IUser|\PHPUnit\Framework\MockObject\MockObject $user */
 		$user = $this->createMock(IUser::class);
 		$user->expects($this->any())
 			->method('getUID')
@@ -874,10 +876,12 @@ class ManagerTest extends TestCase {
 	}
 
 	public function testSendEvent(): void {
+		/** @psalm-suppress DeprecatedInterface Test for deprecated interface */
 		$handler1 = $this->createMock(ICommentsEventHandler::class);
 		$handler1->expects($this->exactly(4))
 			->method('handle');
 
+		/** @psalm-suppress DeprecatedInterface Test for deprecated interface */
 		$handler2 = $this->createMock(ICommentsEventHandler::class);
 		$handler1->expects($this->exactly(4))
 			->method('handle');
@@ -932,35 +936,18 @@ class ManagerTest extends TestCase {
 
 		$manager = $this->getManager();
 
-		$planetClosure = function ($name) {
-			return ucfirst($name);
-		};
+		$planetClosure = static fn (string $name): string => ucfirst($name);
 		$manager->registerDisplayNameResolver('planet', $planetClosure);
 		$manager->registerDisplayNameResolver('planet', $planetClosure);
 	}
 
 
-	public function testRegisterResolverInvalidType(): void {
-		$this->expectException(\InvalidArgumentException::class);
-
-		$manager = $this->getManager();
-
-		$planetClosure = function ($name) {
-			return ucfirst($name);
-		};
-		$manager->registerDisplayNameResolver(1337, $planetClosure);
-	}
-
-
 	public function testResolveDisplayNameUnregisteredType(): void {
 		$this->expectException(\OutOfBoundsException::class);
 
 		$manager = $this->getManager();
 
-		$planetClosure = function ($name) {
-			return ucfirst($name);
-		};
-
+		$planetClosure = static fn (string $name): string => ucfirst($name);
 		$manager->registerDisplayNameResolver('planet', $planetClosure);
 		$manager->resolveDisplayName('galaxy', 'sombrero');
 	}
@@ -968,34 +955,18 @@ class ManagerTest extends TestCase {
 	public function testResolveDisplayNameDirtyResolver(): void {
 		$manager = $this->getManager();
 
-		$planetClosure = function () {
-			return null;
-		};
-
+		$planetClosure = static fn (): null => null;
 		$manager->registerDisplayNameResolver('planet', $planetClosure);
 		$this->assertIsString($manager->resolveDisplayName('planet', 'neptune'));
 	}
 
-	public function testResolveDisplayNameInvalidType(): void {
-
-		$manager = $this->getManager();
-
-		$planetClosure = function () {
-			return null;
-		};
-
-		$manager->registerDisplayNameResolver('planet', $planetClosure);
-		$this->expectException(\InvalidArgumentException::class);
-		$this->assertIsString($manager->resolveDisplayName(1337, 'neptune'));
-	}
-
 	private function skipIfNotSupport4ByteUTF(): void {
 		if (!$this->getManager()->supportReactions()) {
 			$this->markTestSkipped('MySQL doesn\'t support 4 byte UTF-8');
 		}
 	}
 
-	#[\PHPUnit\Framework\Attributes\DataProvider('providerTestReactionAddAndDelete')]
+	#[DataProvider(methodName: 'providerTestReactionAddAndDelete')]
 	public function testReactionAddAndDelete(array $comments, array $reactionsExpected): void {
 		$this->skipIfNotSupport4ByteUTF();
 		$manager = $this->getManager();
@@ -1067,7 +1038,7 @@ class ManagerTest extends TestCase {
 			[$message, $actorId, $verb, $parentText] = $comment;
 			$parentId = null;
 			if ($parentText) {
-				$parentId = (string)$comments[$parentText]->getId();
+				$parentId = $comments[$parentText]->getId();
 			}
 			$id = '';
 			if ($verb === 'reaction_deleted') {
@@ -1080,7 +1051,7 @@ class ManagerTest extends TestCase {
 		return $comments;
 	}
 
-	#[\PHPUnit\Framework\Attributes\DataProvider('providerTestRetrieveAllReactions')]
+	#[DataProvider(methodName: 'providerTestRetrieveAllReactions')]
 	public function testRetrieveAllReactions(array $comments, array $expected): void {
 		$this->skipIfNotSupport4ByteUTF();
 		$manager = $this->getManager();
@@ -2342,7 +2313,7 @@ class ManagerTest extends TestCase {
 		];
 	}
 
-	#[\PHPUnit\Framework\Attributes\DataProvider('providerTestRetrieveAllReactionsWithSpecificReaction')]
+	#[DataProvider(methodName: 'providerTestRetrieveAllReactionsWithSpecificReaction')]
 	public function testRetrieveAllReactionsWithSpecificReaction(array $comments, string $reaction, array $expected): void {
 		$this->skipIfNotSupport4ByteUTF();
 		$manager = $this->getManager();
@@ -2395,7 +2366,7 @@ class ManagerTest extends TestCase {
 		];
 	}
 
-	#[\PHPUnit\Framework\Attributes\DataProvider('providerTestGetReactionComment')]
+	#[DataProvider(methodName: 'providerTestGetReactionComment')]
 	public function testGetReactionComment(array $comments, array $expected, bool $notFound): void {
 		$this->skipIfNotSupport4ByteUTF();
 		$manager = $this->getManager();
@@ -2462,7 +2433,7 @@ class ManagerTest extends TestCase {
 		];
 	}
 
-	#[\PHPUnit\Framework\Attributes\DataProvider('providerTestReactionMessageSize')]
+	#[DataProvider(methodName: 'providerTestReactionMessageSize')]
 	public function testReactionMessageSize(string $reactionString, bool $valid): void {
 		$this->skipIfNotSupport4ByteUTF();
 		if (!$valid) {
@@ -2491,7 +2462,7 @@ class ManagerTest extends TestCase {
 		];
 	}
 
-	#[\PHPUnit\Framework\Attributes\DataProvider('providerTestReactionsSummarizeOrdered')]
+	#[DataProvider(methodName: 'providerTestReactionsSummarizeOrdered')]
 	public function testReactionsSummarizeOrdered(array $comments, array $expected, bool $isFullMatch): void {
 		$this->skipIfNotSupport4ByteUTF();
 		$manager = $this->getManager();
diff --git a/tests/lib/TestCase.php b/tests/lib/TestCase.php
index 1b387df0eb5..6fb5bc309ed 100644
--- a/tests/lib/TestCase.php
+++ b/tests/lib/TestCase.php
@@ -8,8 +8,6 @@
 
 namespace Test;
 
-use DOMDocument;
-use DOMNode;
 use OC\App\AppStore\Fetcher\AppFetcher;
 use OC\Command\QueueBus;
 use OC\Files\AppData\Factory;
@@ -23,15 +21,12 @@ use OC\Files\ObjectStore\PrimaryObjectStoreConfig;
 use OC\Files\SetupManager;
 use OC\Files\View;
 use OC\Installer;
-use OC\Template\Base;
 use OC\Updater;
-use OCP\AppFramework\QueryException;
 use OCP\Command\IBus;
 use OCP\DB\QueryBuilder\IQueryBuilder;
-use OCP\Defaults;
+use OCP\Files\IRootFolder;
 use OCP\IConfig;
 use OCP\IDBConnection;
-use OCP\IL10N;
 use OCP\IUserManager;
 use OCP\IUserSession;
 use OCP\Lock\ILockingProvider;
@@ -39,69 +34,39 @@ use OCP\Lock\LockedException;
 use OCP\Security\ISecureRandom;
 use OCP\Server;
 use PHPUnit\Framework\Attributes\Group;
-
-if (version_compare(\PHPUnit\Runner\Version::id(), 10, '>=')) {
-	trait OnNotSuccessfulTestTrait {
-		protected function onNotSuccessfulTest(\Throwable $t): never {
-			$this->restoreAllServices();
-
-			// restore database connection
-			if (!$this->IsDatabaseAccessAllowed()) {
-				\OC::$server->registerService(IDBConnection::class, function () {
-					return self::$realDatabase;
-				});
-			}
-
-			parent::onNotSuccessfulTest($t);
-		}
-	}
-} else {
-	trait OnNotSuccessfulTestTrait {
-		protected function onNotSuccessfulTest(\Throwable $t): void {
-			$this->restoreAllServices();
-
-			// restore database connection
-			if (!$this->IsDatabaseAccessAllowed()) {
-				\OC::$server->registerService(IDBConnection::class, function () {
-					return self::$realDatabase;
-				});
-			}
-
-			parent::onNotSuccessfulTest($t);
-		}
-	}
-}
+use Psr\Container\ContainerExceptionInterface;
 
 abstract class TestCase extends \PHPUnit\Framework\TestCase {
-	/** @var \OC\Command\QueueBus */
-	private $commandBus;
+	private QueueBus $commandBus;
 
-	/** @var IDBConnection */
-	protected static $realDatabase = null;
+	protected static ?IDBConnection $realDatabase = null;
+	private static bool $wasDatabaseAllowed = false;
+	protected array $services = [];
 
-	/** @var bool */
-	private static $wasDatabaseAllowed = false;
+	protected function onNotSuccessfulTest(\Throwable $t): never {
+		$this->restoreAllServices();
 
-	/** @var array */
-	protected $services = [];
+		// restore database connection
+		if (!$this->IsDatabaseAccessAllowed()) {
+			\OC::$server->registerService(IDBConnection::class, function () {
+				return self::$realDatabase;
+			});
+		}
 
-	use OnNotSuccessfulTestTrait;
+		parent::onNotSuccessfulTest($t);
+	}
 
-	/**
-	 * @param string $name
-	 * @param mixed $newService
-	 * @return bool
-	 */
-	public function overwriteService(string $name, $newService): bool {
+	public function overwriteService(string $name, mixed $newService): bool {
 		if (isset($this->services[$name])) {
 			return false;
 		}
 
 		try {
 			$this->services[$name] = Server::get($name);
-		} catch (QueryException $e) {
+		} catch (ContainerExceptionInterface $e) {
 			$this->services[$name] = false;
 		}
+		/** @psalm-suppress InternalMethod */
 		$container = \OC::$server->getAppContainerForService($name);
 		$container = $container ?? \OC::$server;
 
@@ -112,14 +77,11 @@ abstract class TestCase extends \PHPUnit\Framework\TestCase {
 		return true;
 	}
 
-	/**
-	 * @param string $name
-	 * @return bool
-	 */
 	public function restoreService(string $name): bool {
 		if (isset($this->services[$name])) {
 			$oldService = $this->services[$name];
 
+			/** @psalm-suppress InternalMethod */
 			$container = \OC::$server->getAppContainerForService($name);
 			$container = $container ?? \OC::$server;
 
@@ -139,17 +101,13 @@ abstract class TestCase extends \PHPUnit\Framework\TestCase {
 		return false;
 	}
 
-	public function restoreAllServices() {
-		if (!empty($this->services)) {
-			if (!empty($this->services)) {
-				foreach ($this->services as $name => $service) {
-					$this->restoreService($name);
-				}
-			}
+	public function restoreAllServices(): void {
+		foreach ($this->services as $name => $service) {
+			$this->restoreService($name);
 		}
 	}
 
-	protected function getTestTraits() {
+	protected function getTestTraits(): array {
 		$traits = [];
 		$class = $this;
 		do {
@@ -177,6 +135,7 @@ abstract class TestCase extends \PHPUnit\Framework\TestCase {
 			if (is_null(self::$realDatabase)) {
 				self::$realDatabase = Server::get(IDBConnection::class);
 			}
+			/** @psalm-suppress InternalMethod */
 			\OC::$server->registerService(IDBConnection::class, function (): void {
 				$this->fail('Your test case is not allowed to access the database.');
 			});
@@ -196,6 +155,7 @@ abstract class TestCase extends \PHPUnit\Framework\TestCase {
 
 		// restore database connection
 		if (!$this->IsDatabaseAccessAllowed()) {
+			/** @psalm-suppress InternalMethod */
 			\OC::$server->registerService(IDBConnection::class, function () {
 				return self::$realDatabase;
 			});
@@ -337,9 +297,13 @@ abstract class TestCase extends \PHPUnit\Framework\TestCase {
 		self::tearDownAfterClassCleanStrayLocks();
 
 		// Ensure we start with fresh instances of some classes to reduce side-effects between tests
+		/** @psalm-suppress DeprecatedMethod */
 		unset(\OC::$server[Factory::class]);
+		/** @psalm-suppress DeprecatedMethod */
 		unset(\OC::$server[AppFetcher::class]);
+		/** @psalm-suppress DeprecatedMethod */
 		unset(\OC::$server[Installer::class]);
+		/** @psalm-suppress DeprecatedMethod */
 		unset(\OC::$server[Updater::class]);
 
 		/** @var SetupManager $setupManager */
@@ -364,30 +328,24 @@ abstract class TestCase extends \PHPUnit\Framework\TestCase {
 
 	/**
 	 * Remove all entries from the share table
-	 *
-	 * @param IQueryBuilder $queryBuilder
 	 */
-	protected static function tearDownAfterClassCleanShares(IQueryBuilder $queryBuilder) {
+	protected static function tearDownAfterClassCleanShares(IQueryBuilder $queryBuilder): void {
 		$queryBuilder->delete('share')
 			->executeStatement();
 	}
 
 	/**
 	 * Remove all entries from the storages table
-	 *
-	 * @param IQueryBuilder $queryBuilder
 	 */
-	protected static function tearDownAfterClassCleanStorages(IQueryBuilder $queryBuilder) {
+	protected static function tearDownAfterClassCleanStorages(IQueryBuilder $queryBuilder): void {
 		$queryBuilder->delete('storages')
 			->executeStatement();
 	}
 
 	/**
 	 * Remove all entries from the filecache table
-	 *
-	 * @param IQueryBuilder $queryBuilder
 	 */
-	protected static function tearDownAfterClassCleanFileCache(IQueryBuilder $queryBuilder) {
+	protected static function tearDownAfterClassCleanFileCache(IQueryBuilder $queryBuilder): void {
 		$queryBuilder->delete('filecache')
 			->runAcrossAllShards()
 			->executeStatement();
@@ -398,7 +356,7 @@ abstract class TestCase extends \PHPUnit\Framework\TestCase {
 	 *
 	 * @param string $dataDir
 	 */
-	protected static function tearDownAfterClassCleanStrayDataFiles($dataDir) {
+	protected static function tearDownAfterClassCleanStrayDataFiles(string $dataDir): void {
 		$knownEntries = [
 			'nextcloud.log' => true,
 			'audit.log' => true,
@@ -423,7 +381,7 @@ abstract class TestCase extends \PHPUnit\Framework\TestCase {
 	 *
 	 * @param string $dir
 	 */
-	protected static function tearDownAfterClassCleanStrayDataUnlinkDir($dir) {
+	protected static function tearDownAfterClassCleanStrayDataUnlinkDir(string $dir): void {
 		if ($dh = @opendir($dir)) {
 			while (($file = readdir($dh)) !== false) {
 				if (Filesystem::isIgnoredDir($file)) {
@@ -444,14 +402,14 @@ abstract class TestCase extends \PHPUnit\Framework\TestCase {
 	/**
 	 * Clean up the list of hooks
 	 */
-	protected static function tearDownAfterClassCleanStrayHooks() {
+	protected static function tearDownAfterClassCleanStrayHooks(): void {
 		\OC_Hook::clear();
 	}
 
 	/**
 	 * Clean up the list of locks
 	 */
-	protected static function tearDownAfterClassCleanStrayLocks() {
+	protected static function tearDownAfterClassCleanStrayLocks(): void {
 		Server::get(ILockingProvider::class)->releaseAll();
 	}
 
@@ -461,48 +419,46 @@ abstract class TestCase extends \PHPUnit\Framework\TestCase {
 	 *
 	 * @param string $user user id or empty for a generic FS
 	 */
-	protected static function loginAsUser($user = '') {
+	protected static function loginAsUser(string $user = ''): void {
 		self::logout();
 		Filesystem::tearDown();
 		\OC_User::setUserId($user);
-		$userObject = Server::get(IUserManager::class)->get($user);
+		$userManager = Server::get(IUserManager::class);
+		$setupManager = Server::get(SetupManager::class);
+		$userObject = $userManager->get($user);
 		if (!is_null($userObject)) {
 			$userObject->updateLastLoginTimestamp();
-		}
-		\OC_Util::setupFS($user);
-		if (Server::get(IUserManager::class)->userExists($user)) {
-			\OC::$server->getUserFolder($user);
+			$setupManager->setupForUser($userObject);
+			$rootFolder = Server::get(IRootFolder::class);
+			$rootFolder->getUserFolder($user);
 		}
 	}
 
 	/**
 	 * Logout the current user and tear down the filesystem.
 	 */
-	protected static function logout() {
-		\OC_Util::tearDownFS();
-		\OC_User::setUserId('');
+	protected static function logout(): void {
+		Server::get(SetupManager::class)->tearDown();
+		$userSession = Server::get(\OC\User\Session::class);
+		$userSession->getSession()->set('user_id', '');
 		// needed for fully logout
-		Server::get(IUserSession::class)->setUser(null);
+		$userSession->setUser(null);
 	}
 
 	/**
 	 * Run all commands pushed to the bus
 	 */
-	protected function runCommands() {
-		// get the user for which the fs is setup
-		$view = Filesystem::getView();
-		if ($view) {
-			[, $user] = explode('/', $view->getRoot());
-		} else {
-			$user = null;
-		}
+	protected function runCommands(): void {
+		$setupManager = Server::get(SetupManager::class);
+		$session = Server::get(IUserSession::class);
+		$user = $session->getUser();
 
-		\OC_Util::tearDownFS(); // command can't reply on the fs being setup
+		$setupManager->tearDown(); // commands can't reply on the fs being setup
 		$this->commandBus->run();
-		\OC_Util::tearDownFS();
+		$setupManager->tearDown();
 
 		if ($user) {
-			\OC_Util::setupFS($user);
+			$setupManager->setupForUser($user);
 		}
 	}
 
@@ -518,7 +474,7 @@ abstract class TestCase extends \PHPUnit\Framework\TestCase {
 	 * @return boolean true if the file is locked with the
 	 *                 given type, false otherwise
 	 */
-	protected function isFileLocked($view, $path, $type, $onMountPoint = false) {
+	protected function isFileLocked(View $view, string $path, int $type, bool $onMountPoint = false) {
 		// Note: this seems convoluted but is necessary because
 		// the format of the lock key depends on the storage implementation
 		// (in our case mostly md5)
@@ -543,6 +499,9 @@ abstract class TestCase extends \PHPUnit\Framework\TestCase {
 		}
 	}
 
+	/**
+	 * @return list<string>
+	 */
 	protected function getGroupAnnotations(): array {
 		if (method_exists($this, 'getAnnotations')) {
 			$annotations = $this->getAnnotations();
@@ -553,7 +512,7 @@ abstract class TestCase extends \PHPUnit\Framework\TestCase {
 		$doc = $r->getDocComment();
 
 		if (class_exists(Group::class)) {
-			$attributes = array_map(function (\ReflectionAttribute $attribute) {
+			$attributes = array_map(function (\ReflectionAttribute $attribute): string {
 				/** @var Group $group */
 				$group = $attribute->newInstance();
 				return $group->name();
@@ -568,75 +527,6 @@ abstract class TestCase extends \PHPUnit\Framework\TestCase {
 
 	protected function IsDatabaseAccessAllowed(): bool {
 		$annotations = $this->getGroupAnnotations();
-		if (isset($annotations)) {
-			if (in_array('DB', $annotations) || in_array('SLOWDB', $annotations)) {
-				return true;
-			}
-		}
-
-		return false;
-	}
-
-	/**
-	 * @param string $expectedHtml
-	 * @param string $template
-	 * @param array $vars
-	 */
-	protected function assertTemplate($expectedHtml, $template, $vars = []) {
-		$requestToken = 12345;
-		/** @var Defaults|\PHPUnit\Framework\MockObject\MockObject $l10n */
-		$theme = $this->getMockBuilder('\OCP\Defaults')
-			->disableOriginalConstructor()->getMock();
-		$theme->expects($this->any())
-			->method('getName')
-			->willReturn('Nextcloud');
-		/** @var IL10N|\PHPUnit\Framework\MockObject\MockObject $l10n */
-		$l10n = $this->getMockBuilder(IL10N::class)
-			->disableOriginalConstructor()->getMock();
-		$l10n
-			->expects($this->any())
-			->method('t')
-			->willReturnCallback(function ($text, $parameters = []) {
-				return vsprintf($text, $parameters);
-			});
-
-		$t = new Base($template, $requestToken, $l10n, $theme);
-		$buf = $t->fetchPage($vars);
-		$this->assertHtmlStringEqualsHtmlString($expectedHtml, $buf);
-	}
-
-	/**
-	 * @param string $expectedHtml
-	 * @param string $actualHtml
-	 * @param string $message
-	 */
-	protected function assertHtmlStringEqualsHtmlString($expectedHtml, $actualHtml, $message = '') {
-		$expected = new DOMDocument();
-		$expected->preserveWhiteSpace = false;
-		$expected->formatOutput = true;
-		$expected->loadHTML($expectedHtml);
-
-		$actual = new DOMDocument();
-		$actual->preserveWhiteSpace = false;
-		$actual->formatOutput = true;
-		$actual->loadHTML($actualHtml);
-		$this->removeWhitespaces($actual);
-
-		$expectedHtml1 = $expected->saveHTML();
-		$actualHtml1 = $actual->saveHTML();
-		self::assertEquals($expectedHtml1, $actualHtml1, $message);
-	}
-
-
-	private function removeWhitespaces(DOMNode $domNode) {
-		foreach ($domNode->childNodes as $node) {
-			if ($node->hasChildNodes()) {
-				$this->removeWhitespaces($node);
-			} else {
-				if ($node instanceof \DOMText && $node->isWhitespaceInElementContent()) {
-					$domNode->removeChild($node);
-				}
-			}
-		}
+		return in_array('DB', $annotations) || in_array('SLOWDB', $annotations);
 	}
 }