@MockBean is not always used

[maxiaohao]

In a test with @MicronautTest we have a mock bean for a JPA repository:

  @Primary
  @MockBean(FooRepository.class) // or @MockBean(FooRepositoryImpl.class)
  FooRepository mockFooRepository() {
    ...
  }

I inspected that there is a race condition in picking which bean is used in the test, even with @Primary as above. Sometimes the mock bean is used while sometimes the actual RepositoryImpl is used and that is totally random.

[graemerocher]

Provide an example that reproduces. Really you should not be using Primary in combination with MockBean

[maxiaohao]

@graemerocher
Here is an example project that can reproduce the issue: https://github.com/maxiaohao/micronaut-test-issue-reproducer
Please clone and run ./gradlew clean test -i. You will then randomly get 1 of the 4 possible results:

1. test pass (mock repository is used), and you'll see logs like:

INFO  com.example.ExampleTest - Getting model FooModel(id=1, name=mock model name), mock foo repository is used.

2. test failing (actual repository is used), and you'll see logs like:

INFO  c.e.repository.FooRepositoryImpl - actual foo repository is used                         
                                                                                                                                                                                                      
com.example.ExampleTest > testFooToBar() FAILED                                                                                                                                                       
    org.opentest4j.AssertionFailedError: expected: <1> but was: <0>                                                                                                                                   
        at org.junit.jupiter.api.AssertionUtils.fail(AssertionUtils.java:54)                                                                                                                          
        at org.junit.jupiter.api.AssertEquals.failNotEqual(AssertEquals.java:195)                                                                                                                     
        at org.junit.jupiter.api.AssertEquals.assertEquals(AssertEquals.java:152)                                                                                                                     
        at org.junit.jupiter.api.AssertEquals.assertEquals(AssertEquals.java:147)                                                                                                                     
        at org.junit.jupiter.api.Assertions.assertEquals(Assertions.java:327)                                                                                                                         
        at com.example.ExampleTest.testFooToBar(ExampleTest.java:47)

3. test failing (no transaction is in progress). If you uncomment the lines in ExampleSingleton.java that persist barModels, you will also get a higher chance to see following exception:

com.example.ExampleTest > testFooToBar() FAILED
    javax.persistence.TransactionRequiredException: no transaction is in progress
        at org.hibernate.internal.SessionImpl.checkTransactionNeeded(SessionImpl.java:3586)
        at org.hibernate.internal.SessionImpl.doFlush(SessionImpl.java:1447)
        at org.hibernate.internal.SessionImpl.flush(SessionImpl.java:1443)
        at org.springframework.orm.hibernate5.SessionFactoryUtils.flush(SessionFactoryUtils.java:147)
        at org.springframework.orm.hibernate5.SpringSessionSynchronization.beforeCommit(SpringSessionSynchronization.java:95)
        at org.springframework.transaction.support.TransactionSynchronizationUtils.triggerBeforeCommit(TransactionSynchronizationUtils.java:96)
        at org.springframework.transaction.support.AbstractPlatformTransactionManager.triggerBeforeCommit(AbstractPlatformTransactionManager.java:922)
        at org.springframework.transaction.support.AbstractPlatformTransactionManager.processCommit(AbstractPlatformTransactionManager.java:730)
        at org.springframework.transaction.support.AbstractPlatformTransactionManager.commit(AbstractPlatformTransactionManager.java:714)
        at org.springframework.transaction.interceptor.TransactionAspectSupport.commitTransactionAfterReturning(TransactionAspectSupport.java:533)
        at io.micronaut.spring.tx.annotation.TransactionInterceptor.intercept(TransactionInterceptor.java:88)
        at io.micronaut.aop.MethodInterceptor.intercept(MethodInterceptor.java:40)
        at io.micronaut.aop.chain.InterceptorChain.proceed(InterceptorChain.java:146)
        at com.example.repository.$BarRepositoryImplDefinition$Intercepted.save(Unknown Source)
        at java.util.stream.ReferencePipeline$11$1.accept(ReferencePipeline.java:372)
        at java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:193)
        at java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1382)
        at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:482)
        at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:472)
        at java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:708)
        at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
        at java.util.stream.ReferencePipeline.collect(ReferencePipeline.java:499)
        at com.example.singleton.ExampleSingleton.fooToBar(ExampleSingleton.java:32)
        at com.example.ExampleTest.testFooToBar(ExampleTest.java:46)

4. infinite wait on micronaut application starts - dead lock?

My env:

OS: Arch Linux x86_64
Kernel: 4.19.33-1-lts
openjdk version "1.8.0_212"
OpenJDK Runtime Environment Corretto-8.212.04.1 (build 1.8.0_212-b04)
OpenJDK 64-Bit Server VM Corretto-8.212.04.1 (build 25.212-b04, mixed mode)

Might be related to disabling the auto transaction wrapping for tests with two datasources, from this: #28

On the other side, if @Primary is not used, I get:

io.micronaut.context.exceptions.NonUniqueBeanException: Multiple possible bean candidates found: [com.example.repository.$FooRepositoryImplDefinition$Intercepted, com.example.$ExampleTest$MockFooRepositoryDefinition$Intercepted]

Hope that information helps. Thank you in advance!

[graemerocher]

Thanks for the example, looking into this now.

[graemerocher]

Root cause micronaut-projects/micronaut-core#1740

[graemerocher]

Fixed upstream and will be in 1.1.3 of Micronaut. Thanks for the report.

[maxiaohao]

@graemerocher 👍 Thanks fox fixing it.