Various issues when importing Axon in Eclipse

[nils-christian]

Hi,

This was originally part of #2855, but I think this deserves an own issue. The described issues occur when importing the current axon-4.8.x branch, but the basic problems should be viable for the main branch as well.

If I open the current axon-4.8.x branch in Eclipse, I am already greeted by two compile errors:

Not sure why. The project itself is recognized by Eclipse as JDK8 project.

This already makes it difficult if not impossible to develop anything.

Now I would try and perform a local "mvn install" with skipped tests, so that I can build the project as fast as possible and close the problematic modules (which works fine, as long as I don't want to develop within the modules with the compile errors).

If one does not have the modules already in the local maven repository, this fails:

Now I have only one chance - to build the project with enabled tests. This, by the way, forces me already to have a docker environment and everything. So I try a "mvn install" without skipping the tests. If one of the tests fails, I am out of luck. I guess I could make sure that surefire continues after a fail, but...well...

At least when using Eclipse, the hurdle to develop for the Axon framework is rather high. I know, I have provided PRs in the past, but to be honest, due to this issues this has become rather cumbersome.

We usually have a quick-install maven profile in our builds which allow to build the project very quickly without running the tests or additional checks.

Best regards

Nils

[smcvb]

Thanks for filing this with us, @nils-christian.

I'm afraid I can't get this resolves or looked at right away, but will try to soon. That would, likely, make it a change we introduce in Axon Framework 4.9.1. As such, I've set the milestone to "Release 4.9.1".

[smcvb]

So, I've spent some time on this yesterday and today, so I have some feedback on the subject.

If I open the current axon-4.8.x branch in Eclipse, I am already greeted by two compile errors: Not sure why. The project itself is recognized by Eclipse as JDK8 project.

After installing Eclipse on my laptop (I'm a Linux user btw), I opened the Axon Framework project to check whether I would get the same exception. The referred to compile errors do not pop up, however...

So, perhaps it's a version thing? Honestly, I haven't used Eclipse since university, so this may be a stupid suggestion. But, nonetheless, which version are you using, @nils-christian? Maybe I can reproduce it if I try to run the same.

Now I would try and perform a local "mvn install" with skipped tests, so that I can build the project as fast as possible and close the problematic modules (which works fine, as long as I don't want to develop within the modules with the compile errors).

Axon Framework's modules have test dependencies on one another for certain utilities. Especially with the split between Spring Boot 2 and Spring Boot 3, it saved us tons of duplication.

Granted, I would prefer these to be collected in a dedicated module. However, we're not there, so sharing is our best bet.

So, the build can skip the tests, but should still build the test code.

We usually have a quick-install maven profile in our builds which allow to build the project very quickly without running the tests or additional checks.

This made sense to me actually, so I added a quick-install profile (in this commit), which sets skipTests to true.

[smcvb]

To give some additional clarity on the above. I would still want to investigate why Axon Framework doesn't open up as intended in Eclipse. In the meantime, if you could share whether the profile (however simple) already helps a little, that would be great, @nils-christian :pray:

[nils-christian]

Hi @smcvb,

First of all: Thank you for taking the time to look into this issue.

So, I checked out Axon (revision 4deda0cd67cd9aa3e89dc85b39c6e6c42d0d7e1a) and installed a new Eclipse with the following version:

Eclipse IDE for Java Developers (includes Incubating components)
Version: 2023-12 (4.30.0)
Build id: 20231201-2043
OS: Windows 10, v.10.0, x86_64 / win32
Java vendor: Eclipse Adoptium
Java runtime version: 21.0.1+12-LTS
Java version: 21.0.1

I removed all Axon dependencies from my local Maven repository, imported the project into Eclipse and performed a full build via build automatically. The compiler shows four errors:

I do agree however, that the same issues to not appear in IntelliJ (or in a Maven build), so this seems to be an issue entirely with Eclipse's internal compiler (JDT). Taking a look at the bug list from JDT, it seems that there are indeed issues regarding generics, especially when raw/wildcard and actual generics are mixed. If I change the signature of EventBusSpanFactory.propagateContext from accepting EventMessage\<T> to EventMessage\<?>, the error is resolved. Very weird behaviour of JDT. I am not sure what should be done about this. It seems wrong (and not very feasible regarding the maintainability) to change the code in any way just to work around a bug of the JDT.

I also tested the quick install profile by running "mvn install --activate-profiles quick-install". A lot of tests are skipped in this run, but not the one in spring-boot-3-integrationtest. Those also fail if the system does not provide a running Docker environment.

I hope this helps.

Best regards

Nils

[smcvb]

Awesome feedback, @nils-christian: this is very helpful.

I'll make adjustments to the profile to ensure it does not pick up the spring-boot-3-integrationtest module. And, check whether I have missed skipping any other tests too.

Concerning the JDT of Eclipse, that's a bummer, actually. Do you, perchance, have the issue reference at hand for Eclipse? It would be nice to collect that info in this issue so that other readers can check it out.

[nils-christian]

Hi @smcvb,

It is a little bit tricky to point to a single issue. Just searching for generics and wilcards in the bug list (https://bugs.eclipse.org/bugs/buglist.cgi?quicksearch=generics%20wildcards) or the specific error message (https://bugs.eclipse.org/bugs/buglist.cgi?quicksearch=Cannot%20infer%20type%20arguments) reveals various issues. A lot of them are also a little bit older without any activity.

Best regards

Nils