使用 Mockito 2.0.7 模拟 lambda 表达式

2022-01-14 00:00:00 unit-testing lambda mockito java junit

我想像这样模拟我的存储库中提供的查询:

I want to mock a query provided on my repository like this:

@Test
public void GetByEmailSuccessful() {
    // setup mocks
    Mockito.when(this.personRepo.findAll()
            .stream()
            .filter(p -> (p.getEmail().equals(Mockito.any(String.class))))
            .findFirst()
            .get())
            .thenReturn(this.personOut);
    Mockito.when(this.communityUserRepo.findOne(this.communityUserId))
            .thenReturn(this.communityUserOut);
...

我的 @Before 方法如下所示:

My @Before method looks like this:

@Before
public void initializeMocks() throws Exception {
    // prepare test data.
    this.PrepareTestData();

    // init mocked repos.
    this.personRepo = Mockito.mock(IPersonRepository.class);
    this.communityUserRepo = Mockito.mock(ICommunityUserRepository.class);
    this.userProfileRepo = Mockito.mock(IUserProfileRepository.class);
}

不幸的是，当我运行测试时，我收到了错误:

Sadly when I run the test I receive the error:

java.util.NoSuchElementException:不存在值

java.util.NoSuchElementException: No value present

当我双击错误时，它指向第一个 lambda 的 .get() 方法.

When I double-click the error it points at the .get() method of the first lambda.

你们中是否有人成功地模拟了一个 lambda 表达式并知道如何解决我的问题?

Have any of you successfully mocked a lambda expression and know how I can solve my problem?

推荐答案

没有必要模拟这么深的调用.只需模拟 personRepo.findAll() 并让 Streaming API 正常工作:

There's no need to mock such deep calls. Simply mock personRepo.findAll() and let the Streaming API work as normal:

Person person1 = ...
Person person2 = ...
Person person3 = ...
List<Person> people = Arrays.asList(person1, person2, ...);
when(personRepo.findAll()).thenReturn(people);

然后代替

.filter(p -> (p.getEmail().equals(Mockito.any(String.class))))

只需将 Person 对象上的 email 设置/模拟为预期值.

just set/mock email on your Person objects to be the expected value.

或者，考虑实现 PersonRepo.findByEmail.

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