Hibernate Reactive Panache guide missing documentation on @TestReactiveTransaction

[edeandrea]

Describe the bug

The Quarkus Hibernate Reactive Panache guide does not have any information on the existence of the @TestReactiveTransaction annotation nor how to use it.

Maybe it doesn't belong in that guide because it isn't specific to Panache Reactive and its more generic to reactive transaction management. That being said, it still isn't discussed anywhere in the guides. I think, too, more is needed than a sentence or two just saying that its there. I think there need to be some examples that show how to use it.

Furthermore, the Tests and transactions section of the getting started testing guide is pretty weak. I think both need to be expanded on somewhere.

Maybe there needs to be a guide or something that talks about transaction management in general?

Expected behavior

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Actual behavior

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How to Reproduce?

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Output of uname -a or ver

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Output of java -version

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GraalVM version (if different from Java)

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Quarkus version or git rev

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Build tool (ie. output of mvnw --version or gradlew --version)

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Additional information

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[quarkus-bot]

/cc @DavideD, @FroMage, @Sanne, @gavinking, @loicmathieu

[loicmathieu]

There is a transaction guide and as you said, there is a section in the testing guide about @TestTransaction, the reactive counterpart should be listed here.

[gsmet]

@DavideD could you have a look at this one? It looks like something we could quickly fix and be done with.

[DavideD]

Yes, I will have a look at it

…

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On 5 Jan 2022, at 18:53, Guillaume Smet ***@***.***> wrote:  @DavideD could you have a look at this one? It looks like something we could quickly fix and be done with. — Reply to this email directly, view it on GitHub, or unsubscribe. Triage notifications on the go with GitHub Mobile for iOS or Android. You are receiving this because you were mentioned.

[DavideD]

Can somebody assign this issue to me, please?

[loicmathieu]

Done ;)

[DavideD]

Thanks

[mkouba]

Hm, it seems that when I use @TestReactiveTransaction in my test I can't use Uni.await() inside the test method anymore; it results in java.lang.IllegalStateException: The current thread cannot be blocked: vert.x-eventloop-thread-15... So what's the idiomatic way of asserting some reactive code?

[mkouba]

Ah, I've just found io.quarkus.test.junit.vertx.UniAsserter. Unfortunately, it seems to be undocumented.

[edeandrea]

There are also some examples in the superheros sample app - https://github.com/quarkusio/quarkus-super-heroes/blob/main/rest-heroes/src/test/java/io/quarkus/sample/superheroes/hero/repository/HeroRepositoryTests.java

[DavideD]

So what's the idiomatic way of asserting some reactive code?

You can use Vert.x unit: https://vertx.io/docs/vertx-unit/java/#_introduction

[DavideD]

It integrates with JUnit: https://vertx.io/docs/vertx-unit/java/#_junit_integration

[edeandrea]

Isnt @Rule from JUnit 4?

[edeandrea]

@mkouba to use @TestReactiveTransaction your test has to be non-blocking, which Uni.await() is inherently blocking.

If you want to go that route (or use the UniAssertSubscriber - some examples of that are in https://github.com/quarkusio/quarkus-super-heroes/blob/main/rest-heroes/src/test/java/io/quarkus/sample/superheroes/hero/service/HeroServiceTests.java) then you can't use the annotation and instead will have to implement your own cleanup within each test.

[DavideD]

For JUnit 5: https://vertx.io/docs/vertx-junit5/java/#_integration_with_junit_5

[edeandrea]

Quarkus also has @RunOnVertxContext (for which I can't seem to find much documentation either).

[mkouba]

to use @TestReactiveTransaction your test has to be non-blocking, which Uni.await() is inherently blocking.

I know but it's a bit confusing as you can do Uni.await() if no @TestReactiveTransaction is present, because the test method body is executed on the main thread and only the panache entity/repository operations is executed on the event loop (see also io.quarkus.hibernate.reactive.panache.common.runtime.AbstractJpaOperations.getSession()).

[FroMage]

This looks like something we should document. I did run into the issue too myself.