带有break语句的while循环的Mockito Junit测试用例

Question

我正在为具有带有break语句的while循环的现有代码编写Junit测试用例（带有jupitar的Junit 5）。

public int deleteRecords(int batchsize) {
   //some code here 
   int totalDeletedRecords = 0;
   while(true) {
       int deleted = deleteRecord();
       if (deleted == 0) { //means no record found to delete
          break;
       }
       totalDeletedRecords += deleted;
   }
}
private int deleteRecord()  {
    List<User> usersList = repository.findAll();  //get the records from the database; 
    if (CollectUtils.isEmpty()) {
        return 0;
    }
    //then deleting the total records batch wise
    //construct list with ids and pass that to delete method
    repository.delete(List of ids);
    return userList.size();
}

我的 Junit 测试用例，

@Test
public void testDeleteRecordSuccess() {
    //mock repository call
    User user = User.builder().name("xyz").build();
    when(repository.findAll()).thenReturn(Arrays.asList(user));
    doNothing().when(repository).delete(anyList());
    int deleted = service.deleteRecords(1000);
    assertEquals(1, deleted);
}

根据模拟，记录的大小始终为 1 并且循环执行无限。循环需要停止，并且所有代码行都应该覆盖。

让我知道如何在这种情况下模拟存储库调用。

Answer 1

也许你应该让

repository.findAll()

返回两次来测试循环。

@Test
public void testDeleteRecordSuccess() {
    // Create a test user
    User user = User.builder().name("xyz").build();
    
    // Create two lists, one with the user and one empty
    List<User> listWithUsers = Arrays.asList(user);
    List<User> emptyList = Collections.emptyList();
    
    // Mock repository calls
    // First call to findAll() will return the list with users, second call will return an empty list
    when(repository.findAll()).thenReturn(listWithUsers, emptyList);
    
    // Mock the .delete() call to do nothing
    doNothing().when(repository).delete(anyList());

    // The service call should now proceed as expected, without any infinite loop
    int deleted = service.deleteRecords(1000);
    
    // Verify that records were 'deleted'
    assertEquals(1, deleted);
    
    // Verify calls to mock object
    verify(repository, times(2)).findAll();
    verify(repository, times(1)).delete(anyList());
}