[FAPI 0.68.0] `FabricDataGenHelper.createRegistryWrapper` changes bootstrap order.

I am trying to use the DataGen to create all relevant files for my Biomes and Features by adding custom bootstrap methods to the buildRegistry entry point:

@Override
public void buildRegistry(RegistrySetBuilder registryBuilder) {
    registryBuilder.add(Registries.CONFIGURED_FEATURE, TestConfiguredFeatures::bootstrap);
    registryBuilder.add(Registries.PLACED_FEATURE, TestPlacedFeatures::bootstrap);
    registryBuilder.add(Registries.BIOME, TestBiomes::bootstrap);
    registryBuilder.add(Registries.NOISE_SETTINGS, NoiseDatagen::bootstrap);
}

The PLACED_FEATURE-Bootstrap relies on objects created in the CONFIGURED_FEATURE-bootstrap, and BIOMEs rely on the PLACED_FEATUREs.

If the bootstrap for those Biomes is called before the features are initialised, there may be odd behaviour.

Unfortunately, FabricDataGenHelper.createRegistryWrapper does not run toe bootstrap sequence in the same order as BuiltinRegistries.REGISTRY_BUILDER. This is due to the use of an unordered value-set of a HasMap that will populate the RegistryBuilder: https://github.com/FabricMC/fabric/blob/70063eb9397d2a82209d3c048881952ab3cae94d/fabric-data-generation-api-v1/src/main/java/net/fabricmc/fabric/impl/datagen/FabricDataGenHelper.java#L180 https://github.com/FabricMC/fabric/blob/70063eb9397d2a82209d3c048881952ab3cae94d/fabric-data-generation-api-v1/src/main/java/net/fabricmc/fabric/impl/datagen/FabricDataGenHelper.java#L192-L194

I think the new RegistryBuilder should retain the original order that is used in BuiltinRegistries.REGISTRY_BUILDER for all vanilla Registries.

[modmuss50]

I believe this is working as intenteded using the RegistryEntry.Reference is the expected way of doing this. If you do have a use case where this doesnt work for please let me know.

[quiqueck]

Maybe I should also show how we use those Methods This is a simplified Version of what is actually going on in our Code:

public class MyConfiguredFeatures {
    public static RegistryEntry<ConfiguredFeature<?, ?>> FEATURE_A 
        = getReference(someID, createConfiguredFeatureA() );

    public static void bootstrap(Registerable <ConfiguredFeature<?, ?>> registerable) {
        FEATURE_A = register(
            registerable,
            FEATURE_A.unwrapKey().orElseThrow().location(),
            holder.value()
        );
    }
}

So when bootstrapping PlacedFeature, FEATURE_A would wither be an unbound Reference or a bound RegistryEntry. We can use both to create the PlacedFeatures.

Whenever the bootstrap process of ConfiguredFeatures runs, it will take the information that is already stored in the RegistryEntry (remeber our Version of the Reference holds both the key and the value) to register those with the Registry.