[Bug]: `dab validate` should at least `warn` when zero entities are in the config.

[JerryNixon]

What?

dab validate returns "Config is valid". when there are zero entities.

• entities can be added by autoentities
• entities can be added by entities

But when autoentities is not configured and entities is empty, validate should warn:

[WARN] No entities are defined in this configuration.

Important

This is NOT an error because it could be the top-level configuration in a multi-config environment.

[aaronburtle]

RCA

This is a missing feature/validation gap, not a regression. There are two relevant code paths:

The RuntimeConfig constructor (around line 315) has a check that throws a DataApiBuilderException if both the entities and autoentities properties are completely absent (null). However, if entities is present but empty (an empty JSON object like "entities": {}), the deserialization produces a RuntimeEntities with a Count of 0 but the Entities parameter itself is not null. So the constructor check passes and no error is thrown.

The TryValidateConfig method in the RuntimeConfigValidator class performs schema validation, permission validation, relationship validation, and entity metadata validation, but none of these checks warn when Entities is present but empty. There is simply no code path that checks for this condition.

Version

This was not a regression, the validate command has never warned on empty entities.