如何先创建一些测试弹簧豆

Question

I have production bean A and in @TestConfiguration bean B. Non of those beans depends on each other. But in tests I want bean B to be instantiated before bean A. that's because B prepares local testing environment for A. How can i achieve it?

i can't just annotate A with @DependsOn because B is available only in some tests and i don't want to bind production code with tests.

Answer 1

But in tests I want bean B to be instantiated before bean A

...

and i don't want to bind production code with tests.

Something like this?

@Profile("test")
@Bean
public BeanB beanB() {
    return new BeanB();
}

@Profile("test")
@Bean
public BeanA beanA(BeanB beanB) {
    return new BeanA();
}

@Profile("!test")
@Bean
public BeanA beanA() {
    return new BeanA();
}

Answer 2

There's no easy way to do what you're asking. Your best bet is to have an optional dependency in A. In production, the dependency will be missing and so will be ignored. In the tests, you will provide a bean which contains your test preparation implementation.

Yes, you are adding a little bit of additional complexity for the sake of tests which is not ideal but it's very limited.

Forgive the terrible names:

interface APreparer {
    void prepareA();
}

@Component
public class A {
     public A(final Optional<APreparer> preparer) {
          preparer.ifPresent(APreparer::prepareA);
     }
}

Answer 3

You can create a TestApplication (in src/test/java ) that trivially extends your actual Spring Boot application class and have that depend on your test bean. Then tell SpringBootTest to load your TestApplication instead of the production application.

Example TestApplication:

@DependsOn("beanB")
@Configuration
@Import(YourApplication.class)
public class TestApplication {}

Example test class:

@RunWith(SpringRunner.class)
@SpringBootTest(classes = TestApplication.class)
public class YourApplicationTests {
...