Sync user backend test

tests/unit/UserBackendTest.php

@@ -146,8 +146,6 @@ public function testUpdateAttributes() {
 		$this->getMockedBuilder(['getDisplayName', 'setDisplayName']);
 		/** @var IUser|\PHPUnit_Framework_MockObject_MockObject $user */
 		$user = $this->createMock(IUser::class);
-		$groupA = $this->createMock(IGroup::class);
-		$groupC = $this->createMock(IGroup::class);
 
 		$this->config
 			->expects($this->at(0))
@@ -199,35 +197,8 @@ public function testUpdateAttributes() {
 
 		$this->groupManager
 			->expects($this->once())
-			->method('getUserGroupIds')
-			->with($user)
-			->willReturn(['groupA', 'groupB']);
-		$this->groupManager
-			->expects($this->once())
-			->method('groupExists')
-			->with('groupC')
-			->willReturn(false);
-		$this->groupManager
-			->expects($this->once())
-			->method('createGroup')
-			->with('groupC');
-
-		// updateAttributes first adds new groups, then removes old ones
-		// In this test groupA is removed from the user, groupB is unchanged
-		// and groupC is added
-		$this->groupManager
-			->expects($this->exactly(2))
-			->method('get')
-			->withConsecutive(['groupC'], ['groupA'])
-			->willReturnOnConsecutiveCalls($groupC, $groupA);
-		$groupA
-			->expects($this->once())
-			->method('removeUser')
-			->with($user);
-		$groupC
-			->expects($this->once())
-			->method('addUser')
-			->with($user);
+			->method('replaceGroups')
+			->with($user->getUID(), ['groupB', 'groupC']);
 
 		$this->userBackend->updateAttributes('ExistingUser', [
 			'email' => '[email protected]',