A C++, header-only library for constructing JSON and JSON-like data formats, with JSON Pointer, JSON Patch, JSON Schema, JSONPath, JMESPath, CSV, MessagePack, CBOR, BSON, UBJSON
And this could maybe also run a few examples, redirect output in a text file.
And you could include the checked text files for comparison. This way a bug in the library may show up as output changes.
When building with cmake, please not just do unit tests, but also build all examples to check if they compile.