問題描述

我正在嘗試編寫一個(gè)簡(jiǎn)單的單元測(cè)試，以驗(yàn)證在特定條件下，我的應(yīng)用程序中的類將通過標(biāo)準(zhǔn)日志記錄 API 記錄錯(cuò)誤.我不知道測(cè)試這種情況的最干凈的方法是什么.

I'm trying to write a simple unit test that will verify that, under a certain condition, a class in my application will log an error via the standard logging API. I can't work out what the cleanest way to test this situation is.

我知道鼻子已經(jīng)通過它的日志插件捕獲日志輸出，但這似乎是為了作為失敗測(cè)試的報(bào)告和調(diào)試幫助.

I know that nose already captures logging output through it's logging plugin, but this seems to be intended as a reporting and debugging aid for failed tests.

我可以看到的兩種方法是:

The two ways to do this I can see are:

• 以零碎的方式 (mymodule.logging = mockloggingmodule) 或使用適當(dāng)?shù)哪M庫(kù)來模擬日志模塊.
• 編寫或使用現(xiàn)有的鼻子插件來捕獲輸出并進(jìn)行驗(yàn)證.

如果我采用前一種方法，我想知道將全局狀態(tài)重置為模擬日志模塊之前的狀態(tài)的最簡(jiǎn)潔方法.

If I go for the former approach, I'd like to know what the cleanest way to reset the global state to what it was before I mocked out the logging module.

期待您對(duì)此的提示和技巧...

Looking forward to your hints and tips on this one...

推薦答案

我曾經(jīng)模擬記錄器，但是在這種情況下我發(fā)現(xiàn)最好使用記錄處理程序，所以我基于 jkp 建議的文件(現(xiàn)在已經(jīng)死了，但緩存在 互聯(lián)網(wǎng)檔案)

I used to mock loggers, but in this situation I found best to use logging handlers, so I wrote this one based on the document suggested by jkp(now dead, but cached on Internet Archive)

class MockLoggingHandler(logging.Handler):
    """Mock logging handler to check for expected logs."""

    def __init__(self, *args, **kwargs):
        self.reset()
        logging.Handler.__init__(self, *args, **kwargs)

    def emit(self, record):
        self.messages[record.levelname.lower()].append(record.getMessage())

    def reset(self):
        self.messages = {
            'debug': [],
            'info': [],
            'warning': [],
            'error': [],
            'critical': [],
        }

這篇關(guān)于在鼻子下測(cè)試 Python 代碼時(shí)，我應(yīng)該如何驗(yàn)證日志消息?的文章就介紹到這了，希望我們推薦的答案對(duì)大家有所幫助，也希望大家多多支持html5模板網(wǎng)！