Validation results differ on equivalen JSON and CBOR input

In an example in which different branches allow different types, validation of an AIU valid data structure succeeds when processing JSON, but fails when processing CBOR.

Inputs

features.json:

{"Foo": {}}

features.cbor:

a1 63 46 6f 6f a0

schema.cddl:

root = group

group = {
    ? "help" => tstr,
    ? "features" => feature-set,
    * group-label => group,
    }

feature-set = {
    + feature-label => feature-help
}

group-label = tstr

feature-label = tstr
feature-help = tstr

Failure mode

Works for JSON:

$ cddl validate --cddl schema.cddl --json features.json
[INFO] Root type for validation: root
[INFO] Validation of "features.json" is successful

Fails for CBOR:

$ cddl validate --cddl schema.cddl --cbor features.cbor
[INFO] Root type for validation: root
[ERROR] Validation of "features.cbor" failed: error validating at cbor location /Map([]): expected object value of type tstr, got object

Further information / context

I'm aware that this is not great CDDL -- it's capturing a particular snapshot of development, and we'll move on to something that's easier to parse as https://github.com/RIOT-OS/RIOT/pull/20366 progresses. Nonetheless, AIU this is a bug in the CDDL implementation (which I'm actually using through pycddl, and thus can't even work around by using JSON for the data that's originally YAML anyway).

anweiss / cddl