在Python中嘲弄子進程調用

Question

我有一個方法（run_script）想測試。具體而言，我想測試是否發生了對subprocess.Popen的調用。測試subprocess.Popen時使用某些參數會更好。當我運行測試但是我得到TypeError: 'tuple' object is not callable。

如何測試我的方法以確保子進程實際上是使用mock調用的？

@mock.patch('subprocess.Popen') 
def run_script(file_path): 
    process = subprocess.Popen(['myscript', -M, file_path], stdout=subprocess.PIPE) 
    output,err = process.communicate() 
    return process.returncode 

def test_run_script(self, mock_subproc_popen): 
    mock_subproc_popen.return_value = mock.Mock(communicate=('ouput','error'), returncode=0) 
    am.account_manager("path") 
    self.assertTrue(mock_subproc_popen.called) 

Answer 1

您使用補丁裝飾在run_script功能，因爲你不通過一個模擬的說法有它看似尋常給我。

如何：

def run_script(file_path): 
    process = subprocess.Popen(['myscript', -M, file_path], stdout=subprocess.PIPE) 
    output,err = process.communicate() 
    return process.returncode 

@mock.patch('subprocess.Popen') 
def test_run_script(self, mock_subproc_popen): 
    process_mock = mock.Mock() 
    attrs = {'communicate.return_value': ('output', 'error')} 
    process_mock.configure_mock(**attrs) 
    mock_subproc_popen.return_value = process_mock 
    am.account_manager("path") # this calls run_script somewhere, is that right? 
    self.assertTrue(mock_subproc_popen.called) 

現在，你的嘲笑subprocess.Popen似乎返回一個元組，causeing process.communicate（）籌集TypeError: 'tuple' object is not callable.。因此，mock_subproc_popen上的return_value恰到好處是非常重要的。