在python中，如何为打开文件使用的函数编写单元测试？

import unittest
from file_operations import open_file

class FileOperationsTest(unittest.TestCase):
    def test_open_file(self):
        # 测试逻辑
        pass

def test_open_file(self):
    file_path = "test.txt"
    content = open_file(file_path)
    self.assertEqual(content, "Hello, World!")

def setUp(self):
    # 创建测试文件
    with open("test.txt", "w") as f:
        f.write("Hello, World!")

def tearDown(self):
    # 删除测试文件
    os.remove("test.txt")

if __name__ == '__main__':
    unittest.main()

import unittest
import os
from file_operations import open_file

class FileOperationsTest(unittest.TestCase):
    def setUp(self):
        # 创建测试文件
        with open("test.txt", "w") as f:
            f.write("Hello, World!")

    def tearDown(self):
        # 删除测试文件
        os.remove("test.txt")

    def test_open_file(self):
        file_path = "test.txt"
        content = open_file(file_path)
        self.assertEqual(content, "Hello, World!")

if __name__ == '__main__':
    unittest.main()