import io, unittest
TESTFN = "hello.txt"

class misctests(unittest.TestCase):
    def testIOErrorOnClose(self):
        
        def assertCloseOK(stream):
            def ioerror():
                raise IOError("dummy error again")
            
            stream.flush = ioerror
            self.assertRaises(IOError, stream.close)
            self.assertEqual(True, stream.closed)
        
        assertCloseOK(io.open(TESTFN, "wb", buffering=100))
        assertCloseOK(io.open(TESTFN, "rb", buffering=100))
        assertCloseOK(io.open(TESTFN, "w+b", buffering=100))
        assertCloseOK(io.open(TESTFN, "r", buffering=100))
        assertCloseOK(io.open(TESTFN, "w", buffering=100))
        assertCloseOK(io.open(TESTFN, "w+", buffering=100))

unittest.main()