問題描述

假設(shè)這是代碼

def move(*args, **kwargs):   
    try:
        shutil.move(source, destination)
    except Exception as e:
        raise e

在我的tests.py中

and in my tests.py

@patch.object(shutil, 'move')
def test_move_catch_exception(self, mock_rmtree):
    ''' Tests moving a target hits exception. '''
    mock_rmtree.side_effect = Exception('abc')
    self.assertRaises(Exception, move,
                             self.src_f, self.src_f, **self.kwargs)

它是這么說的

  File "unittests.py", line 84, in test_move_catch_exception
    self.src_f, self.src_f, **self.kwargs)
AssertionError: Exception not raised

如果我在 mock_rmtree 上斷言它會通過.如何對調(diào)用者進(jìn)行斷言(在本例中為函數(shù) move)?

If I assert on mock_rmtree it will pass. How can I assert on the caller (in this case, the function move)?

正如 aquavitae 指出的那樣，主要原因是復(fù)制粘貼錯誤，而且我一開始就斷言了一個元組.始終斷言正確的返回類型...

As aquavitae pointed out, the primary reasons was copy-paste error, and also I was asserting a tuple in the beginning. Always asseert with the right return type...

推薦答案

您的示例中有錯字，缺少 '.

You've got a typo in your example, missing a '.

不完全清楚你在問什么，但如果我理解正確的話，你問的是如何測試在 move 中捕獲了引發(fā)的異常.一個問題是您正在修補 shutil.rmtree，而不是 shutil.move，但您不能確定 shutil.rmtree 是否會永遠(yuǎn)被稱為.shutil.move 僅在成功復(fù)制目錄時才實際調(diào)用 shutil.rmtree ，但是由于您將 self.src_f 復(fù)制到自身，因此不會發(fā)生.雖然這不是一個很好的修補方法，因為 shutil.move 將調(diào)用 shutil.rmtree 的假設(shè)根本無法保證，并且取決于實現(xiàn).

Its not entirely clear what you're asking, but if I understand you correctly, you're asking how to test that a raised exception is caught inside move. One problem is that you're patching shutil.rmtree, not shutil.move, but you can't be certain thatshutil.rmtree will ever be called. shutil.move only actually calls shutil.rmtree if it successfully copies a directory, but since you're copying self.src_f to itself, this doesn't happen. This is not a very good way of patching it though, because the assumption that shutil.move will call shutil.rmtree at all is not guaranteed and is implementation dependent.

至于如何測試，簡單檢查返回值是否符合預(yù)期:

As for how to test it, simply check that the return value is as expected:

@patch.object(shutil, 'move')
def test_move_catch_exception(self, mock_move):
    ''' Tests moving a target hits exception. '''
    e = OSError('abc')
    mock_move.side_effect = e
    returns = move(self.src_f, self.src_f, **self.kwargs)
    assert returns == (False, e)

這篇關(guān)于模擬 - 如何在調(diào)用者上引發(fā)異常?的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網(wǎng)！