beanoverride-in-config-starter-test

Spring Boot Test Starter to make it possible again to use @MockitoBean in @Configuration for tests.

Background

Since Spring Boot 3.4 @MockBean and @MockitoSpyBean became deprecated because support for mocking and spying beans in tests is now directly supported by Spring Framework. The new annotations for this are @MockitoBean and @MocktioSpyBean and you can now also implement your own annotation that overrides beans in a test context.

Old Annotation	New Annotation
@MockBean	@MockitoBean
@SpyBean	@MockitoSpyBean

Sadly, not all features are from Boot are supported by the new annotations. Namely, the following does not work with the new annotations:

Works (old Spring Boot @MockBean):

@SpringJUnitConfig
class MyCfgTests() {

    @Autowired
    MyThing myThingMock;

    @Test
    void test() {

    }

    @Configuration
    public static class MyTestConfig {
        @MockBean //This works
        MyThing myThingMock;
    }
}

Does not work out of the box (new @MockitoBean):

@SpringJUnitConfig
class MyCfgTests() {

    @Autowired
    MyThing myThingMock;

    @Test
    void test() {

    }

    @Configuration
    public static class MyTestConfig {
        @MockitoBean //This does not
        MyThing myThingMock;
    }
}

A list of things not supported anymore:

• Discovery of these annotations inside @Configuration beans: spring-projects/spring-framework#33934
• Directly mocking a BeanFactory: spring-projects/spring-framework#34653
• Creating the bean spied on alongside the spy: spring-projects/spring-framework#33935

But since there are scenarios where it is not practical to create a common annotation for sharing mocks/spies between tests, this project brings back the support for discovery of these annotations on @Configuration beans.

Usage

Just import via

<dependency>
    <groupId>io.github.duoduobingbing</groupId>
    <artifactId>beanoverride-in-config-starter-test</artifactId>
    <version>[1.0,)</version>
    <scope>test</scope>
</dependency>

inside your pom.xml.

The dependency defines a new ContextCustomizerFactory that is autodiscovered via this dependency's spring.factories file.

You can now enjoy working discovery inside your @Configuration classes:

@SpringJUnitConfig
class MyCfgTests() {

    @Autowired
    MyThing myThingMock;

    @Test
    void test() {

    }

    @Configuration
    public static class MyTestConfig {
        @MockitoBean
        MyThing myThingMock;
    }
}

or in another class like this:

@TestConfiguration
class SomeConfigWithMockitoBean() {

    @MockitoBean
    MyThing myThingMock;
}

@SpringJUnitConfig
@Import(SomeConfigWithMockitoBean.class)
class MyCfgTests() {

    @Autowired
    MyThing myThingMock;

    @Test
    void test() {

    }
}

Your own custom implementations with e.g. @BeanOverride(YourCustomBeanOverrideProcessor.class) will be discovered as well.

Prerequisites

Minimum Java Version: 21 (LTS)

beanoverride-in-config Version	Supported Spring Boot Version(s)
1.0	3.4.5-3.4.X1 3.5.X
1.1 (not released yet)	4.0.0

Footnotes

1. ❌️ Not supported: Spring Boot ≦ 3.4.4 ↩