add tests for cached mount provider migration

Author: icewind1991

tests/lib/Files/Config/UserMountCacheTest.php

@@ -507,4 +507,29 @@ public function testGetUsedSpaceForUsers() {
 		$result = $this->cache->getUsedSpaceForUsers([$user1, $user2]);
 		$this->assertEquals(['u1' => 100], $result);
 	}
+
+
+	public function testMigrateMountProvider() {
+		$user1 = $this->userManager->get('u1');
+
+		[$storage1, $rootId] = $this->getStorage(2);
+		$rootId = $this->createCacheEntry('', 2);
+		$mount1 = new MountPoint($storage1, '/foo/');
+		$this->cache->registerMounts($user1, [$mount1]);
+
+		$this->clearCache();
+
+		$cachedMounts = $this->cache->getMountsForUser($user1);
+		$this->assertCount(1, $cachedMounts);
+		$this->assertEquals('', $cachedMounts[0]->getMountProvider());
+
+		$mount1 = new MountPoint($storage1, '/foo/', null, null, null, null, 'dummy');
+		$this->cache->registerMounts($user1, [$mount1], ['dummy']);
+
+		$this->clearCache();
+
+		$cachedMounts = $this->cache->getMountsForUser($user1);
+		$this->assertCount(1, $cachedMounts);
+		$this->assertEquals('dummy', $cachedMounts[0]->getMountProvider());
+	}
 }