Question

我正在尝试为一个函数编写单元测试，该函数将FTP会话作为输入参数以及一些其他参数。这是功能：

def get_listing_photos_ftp(session, source_system_id, mls_system, mls_num, photo_type, max_photos, skip_first=False,
                           photo_file_name=None):
    """Get Photo from FTP
    session_type = 'FTP' (TREB_DLA)
    Refer to info on FTP photo file names here: http://trebdata.trebnet.com/photos.htm
    """

    del source_system_id, mls_system, photo_type, skip_first

    photos = []

    for photo_num in range(1, max_photos):

        filename = photo_file_name(photo_num, mls_num)

        try:
            """Gets a file (StringIO binary file contents object) from the FTP server. Will raise error if
            file not found.
            """
            photo = session.get_file(filename)

        except socket.error as e:


            raise Exception("FTP server socket error. Error details: " + str(e))

        # Append photo tuple (filename.extension, photo content) - photo may be None if listing has less than 21
        if photo is not None:
            photos.append(photo_tuple(photo_num, photo.getvalue()))

    return photos

我尝试模拟所有可以返回指定值进行测试的函数调用。有人可以指导我更好的计划来解决这种模拟测试。

def test_get_listing_photos_ftp():

    filename = Mock(return_value='\mlsphotos\2\478\N4054478_2.jpg')
    session = Mock(return_value='<common.ftp.FTP object at 0x112092150>')

    #throws an error as I am calling 'session' is a string
    session.get_file = Mock(return_value='00100001 01010000 10101011 10001011 11010111 11001101')
    getvalue = Mock(return_value='asdsadadsdadasd')

    assert photos_helper.get_listing_photos_ftp('session', 'N4067078', 'treb', 'N4067078', 'jpg', 4, False, filename) == []

Answer 1

这里模拟FTP会话的一个例子如下：

def test_get_listing():
    content = 'First line.\n'
    output = StringIO.StringIO()
    output.write(content)
    session = Mock()
    session.get_file = Mock(return_value=output)

    def photo_file_name(x, y):
        return "123.jpg"

    result = get_listing_photos_ftp(session, None, None, 2, None, 3, photo_file_name=photo_file_name)
    assert result == [(1, content), (2, content)]

看看Mock（）对象以及它如何具有我们希望生成session.get_file（）方法调用的return_value。以类似的方式，您可以测试其他方案，例如返回值为无等等。

在pytest中模拟FTP连接

1 个答案: