python try-except 子句中的单元测试未捕获 AssertError

Question

我在测试用例中创建了一个对象，想在它的方法内部进行测试。但是异常被 try-except 子句吞没了。我知道我可以更改 run 中的异常，但这不是我想要的。有没有任何单元测试工具可以处理这个问题的方法？

看来unittest.TestCase的assertTrue方法只是一个普通的断言子句。

class TestDemo(unittest.TestCase):

    def test_a(self):

        test_case = self

        class NestedProc:

            def method1(self):
                print("flag show the method is running")
                test_case.assertTrue(False)

            def run(self):
                try:
                    self.method1()
                except:
                    pass  # can raise here to give the exception but not what I want.

        NestedProc().run() # no exception raised
        # NestedProc().method1() # exception raised

编辑

为清楚起见，我将真实世界的测试用例粘贴到此处。这里最棘手的事情是 ParentProcess 总是成功导致 AssertError 没有正确传播到测试函数。

class TestProcess(unittest.TestCase);

    @pytest.mark.asyncio
    async def test_process_stack_multiple(self):
        """
        Run multiple and nested processes to make sure the process stack is always correct
        """
        expect_true = []

        def test_nested(process):
            expect_true.append(process == Process.current())

        class StackTest(plumpy.Process):

            def run(self):
                # TODO: unexpected behaviour here
                # if assert error happend here not raise
                # it will be handled by try except clause in process
                # is there better way to handle this?
                expect_true.append(self == Process.current())
                test_nested(self)

        class ParentProcess(plumpy.Process):

            def run(self):
                expect_true.append(self == Process.current())
                proc = StackTest()
                # launch the inner process
                asyncio.ensure_future(proc.step_until_terminated())

        to_run = []
        for _ in range(100):
            proc = ParentProcess()
            to_run.append(proc)

        await asyncio.gather(*[p.step_until_terminated() for p in to_run])
        for proc in to_run:
            self.assertEqual(plumpy.ProcessState.FINISHED, proc.state)

        for res in expect_true:
            self.assertTrue(res)

Answer 1

任何 assert* 方法甚至 fail() 都会引发异常。最简单的方法可能是手动设置一个标志，然后 fail()：

def test_a(self):
    success = True

    class NestedProc:
       def method1(self):
           nonlocal success
           success = False
           raise Exception()

       ...

    NestedProc().run()

    if not success:
        self.fail()

python try-except 子句中的单元测试未捕获 AssertError

AssertError not catched in unittest in python try-except clause

python

unit-testing

try-except