Function test_eval_dask_xr_where

xarray/tests/test_eval.py:473–487

Test that xr.where() with dask arrays preserves lazy evaluation.

()

@requires_dask
def test_eval_dask_xr_where() -> None:
    """Test that xr.where() with dask arrays preserves lazy evaluation."""
    from xarray.core.utils import is_duck_dask_array

    ds = Dataset({"a": ("x", np.arange(-5, 5, dtype=float))}).chunk({"x": 5})

    with raise_if_dask_computes():
        result = ds.eval("xr.where(a > 0, a, 0)")

    assert isinstance(result, DataArray)
    assert is_duck_dask_array(result.data)

    # Verify correctness when computed
    expected = xr.where(ds["a"] > 0, ds["a"], 0)
    assert_equal(result, expected)


@requires_dask