Upgrade to Groovy 3.0.0

[dreis2211]

Hi,

as Groovy 3.0.0 is finally released, I was wondering if Spring-Boot should support it. I initially hoped that the upgrade would be easy enough, but there are some things that seem to be not working when I upgrade it. I have a WIP branch where you can see the changes I made so far: master...dreis2211:groovy-3.0.0

Specifically, the Spock framework worries me a bit, because we pull in org.spockframework:spock-core:1.3-groovy-2.5. Also the other tests that seem to fail seem to require further investigation and might needs work on Spring-Framework side (see the bean test that I disabled).

Given that Groovy 2.5.x doesn't really support JDK 14, I thought it might be a good point in time to discuss this as 2.3.0 is not out yet, but on the other hand it's already quite late in its development.

Anyhow, I wanted to start a discussion on this. ;-)

Cheers,
Christoph

[snicoll]

Thanks Christoph, you're beating me to it again :-)

I was discussing this with @jhoeller yesterday and I assumed the upgrade on the framework side was completed (at least locally). Will investigate a bit more.

[dreis2211]

It might on Boot side though. I just couldn't find anything on Boot side, yet. And as the beans support is in the Framework I was thinking that it might needs investigation there. Spring-Framework is only using 3.x if a custom java home is set, so in the end it's not really included, just on the CI as far as I got it. See spring-projects/spring-framework@d521d37

[dreis2211]

spock-2.0-M2 has Groovy 3.x support, but I doubt there will be a final release in time. Nonetheless, updated my branch with it and that fixes some more stuff.

[jhoeller]

As far as we are testing it, all core Spring Framework tests pass with Groovy 3.0 on JDK 14. Granted, there may be subtle issues with our standard binaries (compiled against Groovy 2.5.9 on JDK 8) running against Groovy 3.0; maybe that disabled bean test in Boot in one such case. If you could track it down from Boot's side, I'd be happy to consider specific adaptations at core framework level.

We intend to fully upgrade to Groovy 3.0 for Spring Framework 5.3 later this year. For the time being, it'd be great to remain compatible with both Groovy 2.5 and 3.0 at runtime.

[dreis2211]

I think I nailed it down to the changes made in https://issues.apache.org/jira/browse/GROOVY-8399 for the ImportCustomizer. It seems that they cause the import processing to be skipped in cases where it shouldn't be skipped. Why exactly this is only happening when the beans DSL is involved is not yet 100% clear to me, though. The naive approach of copying the old mechanism to Boot's SmartImportCustomizer fixes the failing bean test.

[dreis2211]

The groovy-3.0.0 branch should now be green (at least it is locally).