# (C) British Crown Copyright 2014, Met Office
#
# This file is part of Iris.
#
# Iris is free software: you can redistribute it and/or modify it under
# the terms of the GNU Lesser General Public License as published by the
# Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# Iris is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with Iris.  If not, see <http://www.gnu.org/licenses/>.
"""
Unit tests for the `iris.fileformats.grib.message._MessageLocation` class.

"""

from __future__ import (absolute_import, division, print_function)

# Import iris.tests first so that some things can be initialised before
# importing anything else.
import iris.tests as tests

import mock

from iris.fileformats.grib._message import _MessageLocation


class Test(tests.IrisTest):
    def test(self):
        message_location = _MessageLocation(mock.sentinel.filename,
                                            mock.sentinel.location)
        patch_target = 'iris.fileformats.grib._message._RawGribMessage.' \
                       'from_file_offset'
        expected = mock.sentinel.message
        with mock.patch(patch_target, return_value=expected) as rgm:
            result = message_location()
        rgm.assert_called_once_with(mock.sentinel.filename,
                                    mock.sentinel.location)
        self.assertIs(result, expected)


if __name__ == '__main__':
    tests.main()
