BaseValueSchema.to_value_cls skips registry lookup when model_extra is non-empty

[xujustinj]

Problem

BaseValueSchema.to_value_cls guards the ValueRegistry.load_value() call behind if not self.model_extra:

def to_value_cls(self, *extra_defs):
    if not self.model_extra:
        value_cls = ValueRegistry.DEFAULT.load_value(self)
        if value_cls is not None:
            return value_cls
    return self.build_value_cls(*extra_defs)

When a registered Value subclass has json_schema_extra (e.g. {"x-resource-type": "collection"}), its generated JSON schema includes extra fields that end up in model_extra when parsed back as a ValueSchema. This causes the registry lookup to be skipped entirely, and build_value_cls resolves the schema structurally — e.g. AceTeamCollectionIdValue(Value[str]) becomes a plain StringValue subclass instead of the registered class.

This breaks can_cast_to because casts registered on AceTeamCollectionIdValue are not found on the anonymous StringValue subclass.

Expected behavior

to_value_cls should always consult the registry first. When model_extra contains non-type-semantic metadata (like x-resource-type), the registered class should still be returned. When model_extra contains actual constraints (like minimum, maxLength), a constrained subclass of the registered class should be built — not a subclass of the structural base type.

Suggested fix

def to_value_cls(self, *extra_defs):
    value_cls = ValueRegistry.DEFAULT.load_value(self)
    if value_cls is not None:
        if not self.model_extra:
            return value_cls
        # Build a constrained subclass of the registered class,
        # not the structural base (StringValue, IntegerValue, etc.)
        return self.build_value_cls(*extra_defs, base_cls=value_cls)
    return self.build_value_cls(*extra_defs)

This requires build_value_cls implementations to accept an optional base_cls override, falling back to the current structural base when not provided.

Workaround

We are currently monkeypatching to_value_cls to always try the registry first and return the registered class directly (ignoring constraints from model_extra). This is lossy for the constraint case but fixes the cast resolution.

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Generated by Claude