如何对聚合进行单元测试可迭代<User>

Question

努力模拟在Java/Mongo中使用汇总时要返回的内容。

我曾尝试使用Mongocursor，但努力理解这一点。我想对此进行单位测试涵盖所有路径。使用Mockito和Testng的最佳方法是什么。

public List<User> getAggregatedList(User user){
  AggregateIterable<User> agg = collection.aggregate(pipeline, User.class)
  List<User> users = new ArrayList<>();
  if (agg != null){
    Iterator<User> it = agg.iterator();
    while(it.hasNext()){
      users.add(it.next());
    } 
  }
return users;
}

我应该能够编写一个测试，例如：

...
expected = Arrays.asList(user1,user2...)
verify(result,expect)

Answer 1

您可以通过模拟迭代器的hasnext((和next((方法来测试它：

@Test
public void testGetAggregatedList() {
    MongoCollection collection = PowerMockito.mock(MongoCollection.class);
    AggregateIterable<User> iterable = PowerMockito.mock(AggregateIterable.class);
    MongoClient client = PowerMockito.mock(MongoClient.class);
    MongoDatabase db = PowerMockito.mock(MongoDatabase.class);
    MongoCursor iterator = PowerMockito.mock(MongoCursor.class);
    User user1 = PowerMockito.mock(User.class);
    User user2 = PowerMockito.mock(User.class);
    MongoDaoDelegator.setClient(client);
    PowerMockito.when(client.getDatabase(anyString())).thenReturn(db);
    PowerMockito.when(db.getCollection(anyString())).thenReturn(collection);
    PowerMockito.when(collection.aggregate(anyList(),any())).thenReturn(iterable);
    PowerMockito.when(iterable.iterator()).thenReturn(iterator);
    PowerMockito.when(iterator.hasNext()).thenReturn(true,true,false);
    PowerMockito.when(iterator.next()).thenReturn(user1,user2);
    getAggregatedList(new User()); 
}

这将为您带来您期望的结果。