configuration-processor does not pick up description from javadoc on inherited properties in different Maven modules

[fjakop]

Affected version: Spring Boot 2.5.3
Build system: Maven 3.6.9

Consider a class annotated with @ConfigurationProperties extending another class located in a different Maven module in the same reactor, the description (JavaDoc) of the parent class' properties is not picked up by the configuration-processor and therefore not written to spring-configuration-metadata.json.

This is rather unhandy because we generate our configuration documentation out of the spring-configuration-metadata.json.

A sample project can be found here https://github.com/fjakop/spring-boot-configuration-processor-description

Check for BProperties#output and CProperties#filenamePattern in spring-configuration-metadata.json, there's no description but should be.

[snicoll]

This is working as expected I am afraid. If the source code of BProperties is not available, we can't extract the documentation and default value as the annotation processor doesn't have access to the source model. If you were expecting it to read that from the generated output of moduleA, this isn't supported, see #18366