Your quality contributions are cheerfully appreciated, however small. Example code and documentation are especially welcome.
Changes ought reflect the style of the surrounding matter, whether code or documentation. The styles used in the C core, the C++ wrappers, and the Rust wrappers are quite distinct; use the appropriate style for the language.
New features should have unit tests. It is appreciated if bugfixes have unit tests, as well. Wrappers in a new language absolutely must have at least some superficial tests (it is not necessary to deeply test the underlying functionality in each language). Adding a wrapper implies that you're prepared to maintain that wrapper; if you can't maintain it, the wrapper will likely be removed.
Escape sequences available from terminfo must not be hard-coded. Routines must check to ensure the relevant escape sequence is valid for the current TERM definition, and not emit it if invalid. Routines emitting characters beyond the 128 elements of ASCII should check for UTF8 availability, and fall back to an ASCII equivalent if not present (or return an error).
Run make test with your changes, and ensure all tests pass. Run
notcurses-demo as well, if your changes affect the core library (or the
demo code).
Notcurses targets the ISO C11 standard. This means you should avoid using
GNU C extensions as they might not work outside GCC/Clang. To verify your
standard compliance on GCC and Clang you can compile with -std=c11 -pedantic
command line arguments.