Add test coverage for improvement multipart encoded mode in rest-client

[jcarranzan]

Summary

Cover this backport--> quarkusio/quarkus#39770 (Improve the multipart encoded mode handling in the rest client)

Please select the relevant options.

• Bug fix (non-breaking change which fixes an issue)
• Dependency update
• Refactoring
• Backport
• New scenario (non-breaking change which adds functionality)
• This change requires a documentation update
• This change requires execution against OCP (use run tests phrase in comment)

Checklist:

• Methods and classes used in PR scenarios are meaningful
• Commits are well encapsulated and follow the best practices

[github-actions]

Following jobs contain at least one flaky test: 'PR - Windows - JVM build - Latest Version'

[michalvavrik]

you are not using encoderMode which means you are not testing modes here

[jcarranzan]

Well, currently I am using by default HTML5 doing this:
@QuarkusApplication(properties = "test.properties") static RestService app = new RestService() .withProperty("quarkus.rest-client.multipart-post-encoder-mode", "HTML5");

Correct me if I am wrong

[michalvavrik]

that's fine if you are going to use encoderMode variable in the future

[github-actions]

Following jobs contain at least one flaky test: 'PR - Linux - JVM build - Latest Version'

[michalvavrik]

IMO you need to wait till future completes otherwise this process may be terminated prematurely by JUnit

[michalvavrik]

I think you are misunderstanding Closeable. TBH I didn't see this before, but I think here the method reference httpServer::close becomes same as

var closeable = new Closeable {

   void close() {
     httpServer.close();
 }

};
return closeable;

which means you are not waiting for the Future.

[rsvoboda]

CI is failing, please look into it @jcarranzan

[jcarranzan]

CI is failing, please look into it @jcarranzan

Thanks @rsvoboda but I will close this PR in favor of--> #1853