import pytest

from xarray.backends.api import _get_default_engine

from . import requires_netCDF4, requires_scipy


@requires_netCDF4
@requires_scipy
def test__get_default_engine():
    engine_remote = _get_default_engine('http://example.org/test.nc',
                                        allow_remote=True)
    assert engine_remote == 'netcdf4'

    engine_gz = _get_default_engine('/example.gz')
    assert engine_gz == 'scipy'

    with pytest.raises(ValueError):
        _get_default_engine('/example.grib')

    engine_default = _get_default_engine('/example')
    assert engine_default == 'netcdf4'