# Copyright 2020 Google LLC
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""Contains convenient helpers for writing tests."""

import os
from unittest import mock


def patch_environ(testcase_obj, env=None):
  """Patch environment."""
  if env is None:
    env = {}

  patcher = mock.patch.dict(os.environ, env)
  testcase_obj.addCleanup(patcher.stop)
  patcher.start()