What is the expected way to define parent/child relationships when authoring extensions

[GABRIELNGBTUC]

Currently, child extension resources only support a subset of the features that native bicep resources do.

Imagine you are authoring a bicep extension to interface with an Azure DevOps service connection. You will have 3 layers in that hierarchy:

1. The organization Organization
2. The project Organization/Project
3. The service connection Organization/Project/Service connection

To interact with that service connection, you will have to write your resources in one of two ways:

First:

param organization string
param project string
param serviceConnection string

resource org 'Organization' existing = {
name: organization
}

resource proj 'Organization/Project' existing = {
name: project
parent: org
}

resource sc 'Organization/Project/ServiceConnection' existing = {
name: serviceConnection
parent: proj
}

Second:

param organization string
param project string
param serviceConnection string

resource org 'Organization' existing = {
name: organization

resource proj 'Project' existing = {
name: project
parent: org

resource sc 'ServiceConnection' existing = {
name: serviceConnection
parent: proj
}
}
}

As you can see, you are forced to always bring a parent property (or something similar) with your types in order to be to communicate the hierarchy to the extension host.

This is why I would like to know:

1. Is there a way to automatically pass the resource identifiers of the parent resource when using nested resources that I may have missed
2. If there is no built-in way to pass that information, are extension authors supposed to use reflection/source generation to automatically generate the parent properties?
3. Is there some plans from the Bicep team to automatically generate those relationships in the future? So that when nesting resources, the local deploy services sends to the extension host an additional properties that recursively contains the identifiers of the parents
   Example:

{
"resource": {
    "type": "Organization/Project/ServiceConnection",
    "apiVersion": "",
    "properties": {...},
    "config": {},
    "parent":
    {
        "type": "Organization/Project",
        "identifiers": {...},
        "parent": {
            "type": "Organization",
            "identifiers": {...}
        }
    }
    }
}

Where extension authors would be responsible to retrieve the parent properties in their handlers.