xarray-regressions 0.0.1

pytest-regressions plugin for xarray

A pytest-regressions plugin for identifying regressions in Xarray objects.

Install

pip install xarray-regressions

Usage

If you're unfamiliar with pytest-regressions, check out their documentation first. xarray-regressions registers a compatible test fixture xarray_regression for detecting regressions in the data or metadata of xr.DataArray and xr.Dataset objects.

from xarray_regressions import XarrayRegressionFixture
import xarray as xr

def make_dataarray() -> xr.DataArray:
    """A dummy method that needs to be tested."""
    return xr.DataArray(
        np.full((2, 4, 3), 1),
        dims=["variable", "y", "x"],
        coords={
            "variable": ["var1", "var2"],
            "y": [1, 2, 3, 4],
            "x": [1, 2, 3],
        },
        name="sample_data",
        attrs={"foo": "bar"},
    )


def test_make_dataarray(xarray_regression: XarrayRegressionFixture):
    """Test that the function always returns an identical xr.DataArray."""
    da = make_dataarray()
    xarray_regression.check(
        da,
        check_names=True,
        check_attrs=True,
    )

Once the test is initialized and the expected result is stored in a NetCDF file, test_make_dataarray will fail if the generated xr.DataArray changes in a future run.

xarray_regression.check uses xr.testing.assert_equal to compare equality of values, dimensions, and coordinates. If atol or rtol are provided, it will use xr.testing.assert_allclose instead. Names and attributes are checked separately. Encodings are not currently checked.