Make sure creation of PyGriffin instance fails in absence of proper configuration.

import os

import pytest

_SUSPEND_VARS = ('GRIFFIN_EXEC', 'ISOXML_EXEC')

@pytest.fixture()

def clean_env():

    cache = {}

    for var in _SUSPEND_VARS:

        val = os.environ.pop(var, default=None)

        if val is not None:

            cache[var] = val

    yield

    # runs on test exit

    os.environ.update(cache)

import os

import pytest

import importlib

from . import clean_env

from pygriffin.pygriffin import PyGriffin, PyGriffinConfig

def test_no_config(clean_env):

    # remove default .rc file location

    PyGriffinConfig._RC_FILE = ""

    # there should be no problem importing PyGriffin

    # with an empty configuration file, but trying to

    # create a PyGriffin instance should raise an exception

    with pytest.raises(RuntimeError) as e_info:

        pyg = PyGriffin(input='fake_input.i', mesh='fake_mesh.i')

        print(pyg.config.griffin_exec)