Does Spring provide stub implementation of JpaRepositories?

Question

I am trying to unit test my Service classes that looks similiar to this:

   @Service
   public class SomeQueryService {

    private final SomeRepository repository;

    public SomeQueryService(SomeRepository repository) {
        this.repository = repository;
    }

    public void doSomething() {
        // code doing some magic
    }
}

SomeRepository is simple repository interface extending JpaRepository interface.

What I want to do is unit test this service to verify whether it is working properly.

I do not want to use mockito to mock repository behaviour instead, I want to have some in-memory implementation (on list or map) that will imitate database behaviour.

Does Spring provide such fake implementations?

I want to avoid making Stub Implementation of such repository by myself as I will be using such tests in many other places.

No it doesn't... Use [Mockito](http://mockito.org) to create a dynamic mock . — M. Deinum, Apr 12 '18 at 07:51
As I mentioned above, I do not want to use mockito, I want stub implementation to mimic real storage. It is too much effort to mantain test with lot of doReturn().when() mumbo-jumbo... — Tomasz Bawor, Apr 12 '18 at 07:56
And what would you gain by including a stub over a mock? You aren't testing anything more then the call... If you have a crappy stub implementation your tests fail not because of your service but your crappy test implementation. If that is what you really want to test test with an in-memory database and let Spring Data JPA create your instance of the repository. — M. Deinum, Apr 12 '18 at 07:57
I want to focus on testing service logic in my test code, I do not want to have lines of mock configuration and verifying interactions with repositories. When service is saving object I want to have access to it by using repository.findAll(), not verifying whether the object is saved by using veryfy(repo).save(...). — Tomasz Bawor, Apr 12 '18 at 08:11
It is 1 line of code... Also you shouldn't use the same mechanism for storing and verifying. When calling `save` you now automatically assume that the `findAll` is working correctly. Next to that with Mockito you could (if you want) even create a general purpose stub if you really wanted to. — M. Deinum, Apr 12 '18 at 08:15
have a look at http://reallifedeveloper.com/creating-in-memory-versions-of-spring-data-jpa-repositories-for-testing/ (https://github.com/reallifedeveloper/rld-repositories-sample) — Ilya Serbis, Sep 15 '18 at 20:53

score 1 · Answer 1 · answered Sep 06 '22 at 20:32

RealLifeDeveloper has created an MIT-licensed helper-class to do just what you want: implement the repository-interface with a plain-old-java-object that just wraps a Collection, and called it "InMemoryJpaRepository". You will still have to implement some logic yourself¹, though it should be easy if your queries are not too complicated.

An article explaining how to do this with example: https://reallifedeveloper.com/creating-in-memory-versions-of-spring-data-jpa-repositories-for-testing/

The repository (which includes other stuff, too) is on github: https://github.com/reallifedeveloper/rld-build-tool

The specific helper-files for creating the inmemory-db are found at https://github.com/reallifedeveloper/rld-build-tools/tree/master/src/main/java/com/reallifedeveloper/tools/test/database/inmemory if you dont want the whole repo.

^{1 The rule "Don't put logic in tests" exists for a reason and is clearly violated here. However, the well-known and widely-used alternatives mentioned by the other answers, H2-testing and extensive mocking, have their drawbacks too.}

score 0 · Answer 2 · answered Apr 12 '18 at 08:02

The type of testing you are referring to is called "Integration Testing" or "End to end testing" since it tests the whole application or a big chunk of it compared to unit tests that test only one method.

https://www.guru99.com/unit-test-vs-integration-test.html

You should not unit test your repositories, since they are already well tested by the spring team.

Solution:

You can create a test that starts the whole spring container using Spring Boot:

Just create a class in your test folder and annotate it with:

@RunWith(SpringRunner.class)
@SpringBootTest
public class MyTestClass {

  @Test
     public void test() {
  }

}

You can then configure an embedded database using H2 so that your test does not use the production database, just follow the Spring Boot Database Initialization doc.

https://docs.spring.io/spring-boot/docs/current/reference/html/howto-database-initialization.html

PS. You can also create a specific profile using the following annotation on your test class:

@ActiveProfiles("test")

Thanks, I am aware of testing using in memory database, I am just looking for a way to make test quick, Setting up spring context takes too long and I want to have instant feedback when I am developing code. Waiting for @SpringBootTest takes just too long for quick and nice feedback loop. — Tomasz Bawor, Apr 12 '18 at 08:08

score 0 · Answer 3 · answered Apr 13 '18 at 05:02

0

No Spring Data does not provide a fake implementation of that interface.

You'll have to create it on your own or use a mocking framework like Mockito.

answered Apr 13 '18 at 05:02

Jens Schauder

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Does Spring provide stub implementation of JpaRepositories?

3 Answers3