SpringBoot Incremental compilation does not keep metadata for inner classes

When the annotation processor runs incrementally, it doesn't keep the properties that are in a nested group (i.e. NestedConfigurationProperty).

When working in the module where the @ConfigurationProperties object is defined, such properties became all the sudden invalid.

Comment From: snicoll

The analysis on #18396 is quite interesting and should help us fix this issue.

Comment From: davinkevin

I think I have the same problem.

I have a class annotated with @NestedConfigurationProperty in a library, then another library use it as a sub section of the properties. Code a better than a long description:

@SpringBootApplication
@EnableConfigurationProperties(FooProperties::class)
class PropertyDemoApplication

fun main(args: Array<String>) {
    runApplication<PropertyDemoApplication>(*args)
}

### Library First level, having for dependency the library second level

@ConstructorBinding
@ConfigurationProperties("foo")
data class FooProperties(
        /**
         * URL of the foo component
         */
        val uri: URI,
        /**
         * Authentication configuration
         */
        @NestedConfigurationProperty
        val auth: AuthenticateProperties
)

### Library Second Level

@ConstructorBinding
data class AuthProperties (
        /**
         * The url of the authenticate component
         */
        val url: URI,
        /**
         * Method 1 of auth
         */
        @NestedConfigurationProperty
        val one: Method1 = Method1(),
        /**
         * Method 2 of auth
         */
        @NestedConfigurationProperty
        val two: Method2 = Method2(),
        /**
         * Method 3 of auth
         */
        @NestedConfigurationProperty
        val three: Method3 = Method3()
)

@ConstructorBinding
data class Method1(
        /**
         * key used for method 1
         */
        val key: String = ""
)

@ConstructorBinding
data class Method2(
        /**
         * token used for method 2
         */
        val token: String = ""
)

@ConstructorBinding
data class Method3 (
        /**
         * keyid
         */
        val keyId: String = "",
        /**
         * key
         */
        val key: String = ""
)

The result in the JSON file, all groups are created but only keys from FooProperties and AuthProperties are generated. Key from MethodX objects are not present in the final json file (in properties key).

Do you think this is link to this issue or should I open another issue @snicoll ?