我试图为下面的函数编写单元测试（从snowflake获取一些数据），但我的单元测试失败了，我无法找出原因。
我的函数

import snowflake.connector 
from service.kms_utils import decrypt 

def get_data_from_snowflake(server_name):
    sql_query = f"Select * from mytable where servername={server_name}"
    server_details = []
    try:
        conn = snowflake.connector.connect(
        user=decrypt(os.environ.get('sfusername')),
        password=decrypt(os.environ.get('sfpwd')),
        account=decrypt(os.environ.get('account')),
        warehouse="wh1"
        )
    
        cs = conn.cursor().execute(sql_query)
        server_details= cs.fetchall()
        conn.close()
    
    except Exception as e:
        if "Could not connect to Snowflake Query backend after" in str(e):
            logger.error(f"Snowflake: Snowflake query timeout. {e}")
        elif "Failed to connect to DB" in str(e):
            logger.error(f"Snowflake: Snowflake DB connection error. {e}")
        else:
            logger.error(f"Snowflake: Failed to get CI validationm data. {e}")
return server_details

我的单元测试如下

import pytest
from unittest.mock import patch, MagicMock
from my_module import get_data_from_snowflake

@patch('snowflake.connector.connect')
def test_get_data_from_snowflake_success(mock_connect):
    #Mock the Snowflake connection object and cursor
    mock_cursor = MagicMock()
    mock_connect.return_value.cursor.return_value.execute.return_value = mock_cursor
    mock_cursor.fetchall.return_value = [(1, 'Server1', 'Details1'), (2, 'Server2', 'Details2')]

    # Call the function being tested
    result = get_data_from_snowflake('Server1')

    # Check that the result is as expected
    assert result == [(1, 'Server1', 'Details1')]

但是Assert失败，因为结果是一个空列表[]。解密字符串时解密函数出错。必须指定一个区域。