Testing¶

Running tests¶

# All tests (CPU path — no GPU required)
uv run pytest

# GPU kernel tests only (requires CUDA GPU)
uv run pytest -m gpu

# Specific module
uv run pytest tests/test_raster_algebra.py

# Verbose with short tracebacks
uv run pytest -v --tb=short

Test structure¶

File	Coverage	Lines
`test_geokeys.py`	GeoKey parsing, affine conversion	153
`test_nvimgcodec_io.py`	nvImageCodec decode, format support	218
`test_raster_algebra.py`	Add/sub/mul/div, nodata, focal ops	217
`test_raster_buffers.py`	OwnedRasterArray, residency, diagnostics	418
`test_raster_io.py`	Read/write via rasterio, metadata	277
`test_raster_label.py`	CCL, connectivity, sieve, morphology	672
`test_raster_polygonize.py`	Polygonize CPU/GPU, ring orientation	416
`test_raster_rasterize.py`	GridSpec, CPU/GPU rasterize	138
`test_raster_zonal.py`	Zonal stats, GPU/CPU dispatch	312

GPU test marker¶

Tests that require a CUDA GPU are marked with @pytest.mark.gpu:

@pytest.mark.gpu
def test_label_gpu():
    ...

GPU tests auto-skip when CuPy is not available. In CI, only CPU tests run (no GPU hardware). GPU tests must be run locally before merging.

Test patterns¶

CPU vs GPU comparison — run the same operation on CPU and GPU, assert results match within tolerance
Roundtrip — write then read, verify data preserved
Nodata propagation — verify nodata sentinel values flow through operations
Edge cases — single-pixel rasters, all-nodata, connectivity variants

Linting¶

# Check
uv run ruff check src/ tests/

# Format
uv run ruff format src/ tests/

# Format check (CI uses this)
uv run ruff format --check src/ tests/

CI¶

GitHub Actions runs on every push/PR to main:

Test job — Python 3.12 + 3.13 matrix, pytest --tb=short -m "not gpu"
Lint job — ruff check + ruff format --check

No GPU tests in CI (no GPU hardware). GPU tests are a local-only gate.