unwrap config instead of just cast

[craig-day]

My app uses MicroProfile Config generically, and also uses the SmallRye implementation. My config provider returns a class called SmallRyeAppSettings which implements Config. I think this is valid according to the MP spec. However, when I try to inject config, I end up with a class cast exception.

Caused by: java.lang.ClassCastException: class my.app.SmallRyeAppSettings cannot be cast to class io.smallrye.config.SmallRyeConfig (my.app.SmallRyeAppSettings and io.smallrye.config.SmallRyeConfig are in unnamed module of loader 'app')

I traced the error to this specific cast.

Following the docs from both MP and SmallRye, I think we should use unwrap when handling results from ConfigProvider.getConfig() rather than casting. I added an instanceof shortcut check here to maintain the previous code path. Probably not necessary.

Alternatively, should this be using the small rye provider directly? Maybe this?

SmallRyeConfigProviderResolver.instance().getConfig(getContextClassLoader());

I'm not sure if this will create a circular dependency so I went with the more generic unwrap route first.

I tried to write a test, but to register an override for a ConfigProvider, you need to create something ServiceLoader can pick up. I couldn't find a nice way to do something for just a single test class that didn't impact all the other test classes.

[radcortez]

Hi, @craig-day Thanks for the PR.

We have other places in the code where we are casting to SmallRyeConfig. Do you mind also fixing these cases?

[craig-day]

@radcortez I've updated all the casts I could find that were not test. Do you think we should unwrap in test too?

[radcortez]

@radcortez I've updated all the casts I could find that were not test. Do you think we should unwrap in test too?

Yes, please, go ahead. Thank you!

[craig-day]

@radcortez I replaced all the casts with unwrap in test too. Also updated to latest main and squashed my commits. Thanks!

[radcortez]

Can you run the build locally to fix the formatting issues and push again? :) Thanks!

[craig-day]

@radcortez updated and pushed :D

[radcortez]

Great! Thank you!