Function test_eval_dask_mixed_backends

xarray/tests/test_eval.py:514–535

Test expressions with mixed dask and numpy arrays.

()

@requires_dask
def test_eval_dask_mixed_backends() -> None:
    """Test expressions with mixed dask and numpy arrays."""
    from xarray.core.utils import is_duck_dask_array

    ds = Dataset(
        {
            "dask_var": ("x", np.arange(10.0)),
            "numpy_var": ("x", np.linspace(0, 1, 10)),
        }
    )
    # Only chunk one variable
    ds["dask_var"] = ds["dask_var"].chunk({"x": 5})

    with raise_if_dask_computes():
        result = ds.eval("dask_var + numpy_var")

    # Result should be dask-backed when any input is dask
    assert is_duck_dask_array(result.data)

    # Verify correctness
    expected = ds["dask_var"] + ds["numpy_var"]
    assert_equal(result, expected)


@requires_dask