pytest-cpplint

A pytest plugin that runs cpplint style checking on C/C++ source files. Each file is collected as a test item and reported as a pass or failure in the normal pytest output.

Useful for Python projects with C extension modules where you already run pytest and want cpplint findings surfaced in the same test run.

Installation

pip install pytest-cpplint

This pulls in cpplint automatically via the cpplint PyPI package.

Usage

The plugin does nothing unless explicitly enabled:

pytest --cpplint

This collects all .c, .cc, .cpp, .cxx, .h, .hpp, and .hxx files and runs cpplint on each one. Files with findings fail; clean files pass.

PASSED src/clean.c::CPPLINT
FAILED src/buggy.c::CPPLINT
  src/buggy.c:12:  Lines should be <= 80 characters long  [whitespace/line_length] [2]

You can combine --cpplint with your normal test run — Python tests and cpplint items appear together in the results.

Configuration

All options go in pyproject.toml, pytest.ini, or setup.cfg under [pytest].

cpplint_args

Extra arguments forwarded to every cpplint invocation. This is the main configuration surface — use it for --filter, --linelength, --root, and any other cpplint flags.

With no cpplint_args, cpplint runs all of its default checks (Google C++ style guide). Use --filter to enable or disable specific categories. A good starting configuration:

[pytest]
cpplint_args =
    --linelength=120
    --filter=-legal/copyright,-build/header_guard

cpplint_extensions

File extensions to collect. Default: .c .cc .cpp .cxx .h .hpp .hxx.

[pytest]
cpplint_extensions = .c .cpp .h

Markers

All cpplint items are marked with cpplint, so you can select or exclude them with -m:

pytest --cpplint -m cpplint           # only cpplint
pytest --cpplint -m "unit or cpplint" # unit tests + cpplint
pytest --cpplint -m "not cpplint"     # everything except cpplint

Caching

Results are cached based on file modification time and cpplint_args. On subsequent runs, files that previously passed are skipped. The cache is automatically invalidated when a file is modified or cpplint_args changes. Caching relies on pytest's built-in cache provider (the .pytest_cache directory). If the cache provider is disabled (for example with -p no:cacheprovider), results will not be cached and all files will be re-checked on each run.

To force a full re-check:

pytest --cpplint --cache-clear

License

MIT