unittest：wxpython 的事件方法引发异常但 assertRaises 未检测到它

Question

我有一个 wxpython 对话框，它在单击“确定”按钮时引发 TypeError 异常。我想用 unittest 测试异常的发生，但测试没有按预期工作。输出显示引发了异常。总之 unittest 通知测试失败：

"C:\Program Files (x86)\Python\python.exe" test.py
Traceback (most recent call last):
  File "test.py", line 22, in on_ok
    raise TypeError( 'TypeError raised' )
TypeError: TypeError raised
F
======================================================================
FAIL: test_should_raise (__main__.CDlgTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "test.py", line 34, in test_should_raise
    self._dut.m_button_ok.GetEventHandler().ProcessEvent( event )
AssertionError: TypeError not raised

----------------------------------------------------------------------
Ran 1 test in 0.005s

FAILED (failures=1)

这是我的代码的简化示例：

import unittest
import wx

class CDlgBase ( wx.Dialog ):
    """The UI"""
    def __init__( self, parent ):
        wx.Dialog.__init__ ( self, parent )
        bSizerTest = wx.BoxSizer( wx.VERTICAL )
        self.m_button_ok = wx.Button( self, wx.ID_ANY )
        bSizerTest.Add( self.m_button_ok, 0 )
        self.SetSizer( bSizerTest )
        # Connect Events
        self.m_button_ok.Bind( wx.EVT_BUTTON, self.on_ok )
    def on_ok( self, event ):
        event.Skip()

class CDlg( CDlgBase ) :
    """The dialog"""
    def __init__(self, parent):
        super( CDlg, self).__init__(parent)
    def on_ok(self, event):
        # The exception should be verified in the test `test_should_raise()`.
        raise TypeError( 'TypeError raised' )

class CDlgTest( unittest.TestCase ) :
    """The test class"""
    def setUp(self):
        self._dut = CDlg(None)
    def test_should_raise(self):
        """The test to verify raising the TypeError exception in the event 
        method `on_ok()`. this is the test method wich works not as expected."""
        event = wx.CommandEvent( wx.EVT_BUTTON.evtType[0] )
        event.SetEventObject( self._dut.m_button_ok )
        with self.assertRaises( TypeError ) :
            """Simulate an "OK" click. `on_ok()` will be executed 
            and raises the TypeError exception."""
            self._dut.m_button_ok.GetEventHandler().ProcessEvent( event )

if __name__ == '__main__':
    app = wx.App()
    tests = [ unittest.TestLoader().loadTestsFromTestCase( CDlgTest) ]
    unittest.TextTestRunner(verbosity=2, failfast=True).run(unittest.TestSuite(tests) )

有人可以帮我找出我做错了什么吗？

Answer 1

参见：https://wiki.wxpython.org/CppAndPythonSandwich

异常不会通过 C++ 层向上传递到调用堆栈。当从 Python 控制 returns 到 C++ 时，它会检查是否存在未捕获的 Python 异常，如果是，则打印并清除错误。

在单元测试中处理这个问题的一种方法是在事件处理程序中捕获异常，并设置一个标志。然后返回测试代码，您可以检查是否设置了该标志。

unittest：wxpython 的事件方法引发异常但 assertRaises 未检测到它

unittest: wxpython's event method raises exception but assertRaises does not detect it

python

unit-testing

wxpython

assertraises

python-2.7