The C++ code generator now handles schemas where the top-level type is
nullable ("type": ["object", "null"], ["string", "null"], or
["array", "null"]).
Changes to weaseljson_schemagen.py:
- Rename the inner object struct when the root is a nullable object, so
the `using Root = std::optional<...>` alias no longer conflicts with
`struct Root`.
- Treat nullable root objects and arrays as container roots, emplacing
the inner value before pushing the root frame and pointing the frame at
the contained value.
- For nullable root scalars/enums, engage() now returns a pointer to the
value inside the optional rather than to the optional wrapper itself.
- cbNull() now safely accepts a top-level null when the root is nullable
and rejects it otherwise.
Regression tests added:
- nullable_object.schema.json + test_nullable_root.cpp
- nullable_string.schema.json
- nullable_array.schema.json
Closes#13
Remove the standalone "Run schemagen tests" workflow step and instead
add the big-schema regression test to contrib/schemagen/CMakeLists.txt
so ctest picks it up alongside schemagen_example. Update README to
document both `ctest` and the convenience `./run_tests.sh`.
Closes#3
Addresses review feedback: keep the schemagen-specific CMake rules
close to the tool instead of inline in the top-level CMakeLists.txt.
The subdirectory file is added from the root and guarded by the same
Python3 availability check that was already in use.