Unexpected positive validation

[pasbi]

Following validation is unexpectedly positive:

int main()
{
  const auto schema = nlohmann::json::parse(R"(
{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "type": "array",
  "$defs": {
    "foo": { "type": "object" }
  },
  "items": {
    "type": "object",
    "$ref": "#/$defs/foo",
    "required": [ "foobar" ]
  }
})");

  const auto instance = nlohmann::json::parse("[{}]");

  nlohmann::json_schema::json_validator m_validator;
  m_validator.set_root_schema(schema);
  fmt::println("schema: {}", schema.dump(4));
  fmt::println("instance: {}", instance.dump(4));
  fmt::println("Validation result: {}", m_validator.validate(instance).dump(4));
}

The problem is, that the validator is happy although the required "foobar" key is missing.
Online tools (like https://www.jsonschemavalidator.net/) affirm that the instance doesn't satisfy the schema.

This is a minimum example to reproduce the issue, the real schema and instance are much larger.

Please let me know if this is a bug or if I'm missing something.

I use json-schema 2.2.0 with nlohmann-json 3.11.3 on g++ 14.2.1.

[pboettch]

This is because $defs is not supported by draft-7, the standard currently supported. Especially in version 2.2.0

Recently #338 has been integrated on the main-branch. Which adds $defs support to this project. But there hasn't been a release with this yet.