Heavily mocked tests are a code smell

mock_everything_poorly.py

@pytest.fixture
def mock_spark_session():
   return mock.Mock(name='spark_session')

def test_get_user_latest_device_df(mock_spark_session):
   mock_raw_dataframe = mock.MagicMock(name='fake_dataframe')
   mock_spark_session.read.json.return_value = mock_raw_dataframe
   mock_user_device_df = mock.Mock(name='mock_user_device')
   mock_raw_dataframe.select.return_value = mock_user_device_df
   fake_s3_path = 's3://foobar'

   user_latest_device_df = get_user_latest_device_df(
       mock_spark_session, fake_s3_path)

   mock_spark_session.read.json.assert_called_once_with(fake_s3_path)
   mock_raw_dataframe.select.assert_called_once_with(
       mock_raw_dataframe['device_id'],
       mock_raw_dataframe['enc_user_id'],
       mock_raw_dataframe['arrival_date'].cast('date')
   )
   mock_user_device_df.createOrReplaceTempView.assert_called_once_with(
       'user_device'
   )
   mock_spark_session.sql.assert_called_once_with(
       mock.ANY
   )
   assert user_latest_device_df == mock_spark_session.sql.return_value