spring-rabbit-test: rabbitListenerAnnotationProcessor has already been defined

[liias]

I am using:
spring boot 2.1.2.RELEASE
spring-rabbit-2.1.3.RELEASE
spring-rabbit-test-2.1.3.RELEASE

When running tests I get an error:

The bean 'org.springframework.amqp.rabbit.config.internalRabbitListenerAnnotationProcessor', defined in class path resource [org/springframework/amqp/rabbit/test/RabbitListenerTestBootstrap.class], could not be registered. A bean with that name has already been defined in class path resource [org/springframework/amqp/rabbit/annotation/RabbitBootstrapConfiguration.class] and overriding is disabled.

Spring suggests to use "spring.main.allow-bean-definition-overriding=true" to override the default behaviour and it does work. However, I find it a bit bad solution to change global spring configuration.

There is also possibility that I am doing something wrong.

[liias]

Just looked into how RabbitBootstrapConfiguration gets loaded in my tests.

Using @RabbitListenerTest does two things:
Enables @EnableRabbit (which does @Import(RabbitBootstrapConfiguration.class))
Adds @Import(RabbitListenerTestBootstrap.class)

Now, I can't do @Import(RabbitListenerTestBootstrap.class) instead of @RabbitListenerTest, because
rabbit-test checks the annotation specifically in org.springframework.amqp.rabbit.test.RabbitListenerTestHarness#RabbitListenerTestHarness.

And even if I could, there are probably some parts of RabbitBootstrapConfiguration I do want to have?

Things to try:

1. annotate
   org.springframework.amqp.rabbit.test.RabbitListenerTestBootstrap#rabbitListenerAnnotationProcessor with @Primary (I need to test it first, this still means overriding, so I assume same error). Update: nope, this doesnt work.

Related spring topic: spring-projects/spring-boot#15216

[garyrussell]

I am not sure why you opened an issue here; this has nothing to do with this project.

Can you explain what you think we can do about it?

[liias]

Hey.

So, I don't know the project well to state facts, so here are my guesses:
You could take away @EnableRabbit from @RabbitListenerTest, so RabbitBootstrapConfiguration is not loaded in. In order to get other beans from RabbitBootstrapConfiguration, the RabbitBootstrapConfiguration could be split up or you could redefine all beans in RabbitListenerTestBootstrap, so RabbitListenerTestBootstrap would be a full replacement for RabbitBootstrapConfiguration.

In that case user can use spring profiles (i.e test vs not test) to choose what bean configurations they choose.

The goal would be making the @RabbitListenerTest work with the spring boot default config spring.main.allow-bean-definition-overriding=false.

Does that make any sense?

[garyrussell]

It makes sense for Boot users but it will break every application that uses @RabbitListenerTest but not Spring Boot.

I don't know if it's possible to make it conditional on whether Boot is present on the class path, but it could be difficult because we'd end up with circular dependencies.

[liias]

If nothing else, then this issue will at least appear in search results for people starting a new project with the test lib.

So you are saying spring.main.allow-bean-definition-overriding=false is very much a spring-boot default, and won't make it into spring proper as default value?

[garyrussell]

The problem is that if we, say, unconditionally set spring.main.allow-bean-definition-overriding=true in the test framework, it could mask the very issue that the Boot team is trying to avoid by making it false by default.

What is the difficulty of adding a TestPropertySource to your test case?

@RabbitListenerTest
@TestPropertySource(properties = "spring.main.allow-bean-definition-overriding=true")

[liias]

@TestPropertySource certainly works. But I would personally just enable it in my application, because if just enabling it when running tests you could inadvertently get errors when actually running application (because tests passed).

In conclusion, I thought spring is advertising to not override beans now and this library (which is part of spring umbrella) does do that, so wanted to let you know.

[garyrussell]

Good point; we'll take a look to see if there is something we can do to avoid this.