3.x: Fix Micronaut integration in Helidon 3.x? #7206

[jbescos]

Description

Using Micronaut 4.x in Helidon 3.x: #7206

Documentation

N/A

A couple of comments:

1. I had to remove helidon/integrations/micronaut/cdi-processor/src/main/java/module-info.java because there was one issue with Micronaut modules having same packages. I opened an issue: the unnamed module reads package io.micronaut.inject.annotation from both io.micronaut.core_processor and io.micronaut.inject micronaut-projects/micronaut-core#10299 . Anyway, as we use this module for annotation processing there is no real need to have a module-info.
2. helidon/integrations/micronaut/cdi/src/test/java/io/helidon/integrations/micronaut/cdi/TestBothBean.java is implementing one intrface with default methods and inherited annotations. I had to override the methods and add again the annotations. It seems a bug in Micronaut.

[jbescos]

There is one issue with validation:
micronaut-projects/micronaut-core#10370

[jbescos]

Now Helidon examples exists in [email protected]:helidon-io/helidon-examples.git, and this makes a problem.

If you make a change in Helidon that requires modifications in examples, you are in a dead lock. You cannot submit in Helidon because examples fails, and you cannot submit in examples because the Helidon changes are not in place.

[jbescos]

Examples fails because it also require changes:
helidon-io/helidon-examples#32

[barchetta]

As you see the examples checks are not required. Therefore, no deadlock. When you are in this situation the procedure is:

1. Proceed with this PR. You will not be blocked by the examples check. You should comment as to why the examples fail to build (so we understand if you are introducing an incompatibility).
2. Create a PR against https://github.com/helidon-io/helidon-examples/tree/dev-3.x to adjust the example (and you already have). It will fail build check until the first PR is merged.
3. Once the first PR is approved you can merge it. You will not be blocked by the examples check.
4. Then the second PR will then pass the build check and you can have it reviewed and merge it.

Yes, this is inconvenient, but it's the cost of moving the examples out of the primary repository.