Python模拟psycopg2连接和游标

Python模拟psycopg2连接和游标,python,unit-testing,mocking,pytest,contextmanager,Python,Unit Testing,Mocking,Pytest,Contextmanager,我无法模拟psycopg2数据库连接和游标,因为我已经对其进行了重构,以便为游标使用上下文管理器。我知道,使用上下文管理器,可以调用其他神奇的方法来设置和清理资源(\uuuuuuuuuuuuuuuuuuuuuuuuuuu,\uuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuu 代码如下: import os import psycopg2 import psycopg2.extras DB_HOST = os.get

我无法模拟psycopg2数据库连接和游标,因为我已经对其进行了重构,以便为游标使用上下文管理器。我知道,使用上下文管理器,可以调用其他神奇的方法来设置和清理资源(
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代码如下:

import os
import psycopg2
import psycopg2.extras

DB_HOST = os.getenv('DB_HOST')     
DB_PORT = os.getenv('DB_PORT')
DB_NAME = os.getenv('DB_NAME')
DB_USER = os.getenv('DB_USER')
DB_PASSWORD = os.getenv('DB_PASSWORD')            
CONN = psycopg2.connect(f'dbname={DB_NAME} user={DB_USER} host={DB_HOST} port={DB_PORT} password={DB_PASSWORD}')

def my_func():
    message = None
    print(CONN)  # Added to debug - this never prints out a magic mock reference

    select_sql = 'SELECT * FROM app.users WHERE name = %s LIMIT 1;'
    with CONN.cursor(cursor_factory = psycopg2.extras.DictCursor) as cursor:
        print(cursor) # Debug - no magic mock reference
        cursor.execute(select_sql, ("Bob"))
        row = cursor.fetchone()

    if row is not None: 
        message = "name found"
    else:
        message = "name not found"

    return message

下面是测试代码和我模拟连接和游标的尝试

import pytest

from src import my_class
from unittest import mock

class TestFunction:
    @mock.patch('psycopg2.connect')
    def test_my_func(self, mock_connect):

        mock_cursor = mock.MagicMock()
        mock_cursor.__enter__.return_value.fetchone.return_value = {
            "id": 1,
            "name": "Bob",
            "age": 25
        }
        mock_connect.return_value.cursor.return_value = mock_cursor

        result = my_class.my_func()
        assert result == "found"

如果在全局连接上调用
CONN
,我不确定如何模拟连接或光标。当前运行的pytest显示测试失败,print语句显示底层对象不是magic mock。如何使用上下文管理器模拟全局数据库连接和数据库游标?感谢您的帮助

我找到了解决办法!我有一种感觉,我的问题在于全局变量
CONN
,我研究了如何模拟python全局变量并进行了尝试。我的书面陈述最终表明,这些例子确实是魔术模拟

在我的测试中,我只调用被测试的方法,而不是用全局变量触发代码,所以只需将其设置为您想要的。一旦你有了答案,听起来就直截了当了,对吗

mock_cursor = mock.MagicMock()
mock_cursor.fetchone.return_value = {
      "id": 1,
      "name": "Bob",
      "age": 25
}
mock_connect.cursor.return_value.__enter__.return_value = mock_cursor
my_class.CONN = mock_connect


没有什么比回答你自己的问题更好的了

我找到了解决办法!我有一种感觉,我的问题在于全局变量
CONN
,我研究了如何模拟python全局变量并进行了尝试。我的书面陈述最终表明,这些例子确实是魔术模拟

在我的测试中,我只调用被测试的方法,而不是用全局变量触发代码,所以只需将其设置为您想要的。一旦你有了答案,听起来就直截了当了,对吗

mock_cursor = mock.MagicMock()
mock_cursor.fetchone.return_value = {
      "id": 1,
      "name": "Bob",
      "age": 25
}
mock_connect.cursor.return_value.__enter__.return_value = mock_cursor
my_class.CONN = mock_connect

没有什么比回答你自己的问题更好的了