Method test_eq_unregister

Lib/test/_test_atexit.py:151–183

(self)

                atexit._clear()

    def test_eq_unregister(self):
        # Issue #112127: callback's __eq__ may call unregister
        def f1():
            log.append(1)
        def f2():
            log.append(2)
        def f3():
            log.append(3)

        class Pred:
            def __eq__(self, other):
                nonlocal cnt
                cnt += 1
                if cnt == when:
                    atexit.unregister(what)
                if other is f2:
                    return True
                return False

        for what, expected in (
                (f1, [3]),
                (f2, [3, 1]),
                (f3, [1]),
            ):
            for when in range(1, 4):
                with self.subTest(what=what.__name__, when=when):
                    cnt = 0
                    log = []
                    for f in (f1, f2, f3):
                        atexit.register(f)
                    atexit.unregister(Pred())
                    atexit._run_exitfuncs()
                    self.assertEqual(log, expected)


if __name__ == "__main__":