def test_get_env_var_missing(self):
env_var_key = 'SOME_ENV_VAR'
with self.assertRaises(ValueError) as context_manager:
Config._get_env_var(env_var_key)
expected = ('Lambda configuration error: '
f'missing environment variable {env_var_key}')
self.assertEqual(str(context_manager.exception), expected)
def test_get_env_var_present(self):
env_var_value = 'some_value'
env_var_key = 'SOME_ENV_VAR'
with patch('os.getenv', MagicMock(return_value=env_var_value)) as mock:
result = Config._get_env_var(env_var_key)
expected = env_var_value
self.assertEqual(result, expected)
mock.assert_called_once_with(env_var_key)