test_facade.py 文件源码

def _mock_output_restore(self):
        """
        Mock methods to ensure that stdout and stderr are restored,
        after they have been captured.

        Return the path to the tempfile that was used to capture the output.
        """
        old_stdout = os.dup(1)
        old_stderr = os.dup(2)
        fd, outfile = tempfile.mkstemp()
        mkstemp_patcher = mock.patch("tempfile.mkstemp")
        mock_mkstemp = mkstemp_patcher.start()
        self.addCleanup(mkstemp_patcher.stop)
        mock_mkstemp.return_value = (fd, outfile)

        dup_patcher = mock.patch("os.dup")
        mock_dup = dup_patcher.start()
        self.addCleanup(dup_patcher.stop)
        mock_dup.side_effect = lambda fd: {1: old_stdout, 2: old_stderr}[fd]

        dup2_patcher = mock.patch("os.dup2", wraps=os.dup2)
        mock_dup2 = dup2_patcher.start()
        self.addCleanup(dup2_patcher.stop)
        return outfile, mock_dup2