- expected: total number of expected bytes (or None if unknown)

"""

def __init__(self, partial, expected):

r_expected = 'undefined' if expected is None else repr(expected)

super().__init__(f'{len(partial)} bytes read on a total of '

f'{expected!r} expected bytes')

f'{r_expected} expected bytes')

self.partial = partial

self.expected = expected

def test_readuntil_eof(self):

stream = asyncio.StreamReader(loop=self.loop)

stream.feed_data(b'some dataAA')

data = b'some dataAA'

stream.feed_data(data)

stream.feed_eof()

with self.assertRaises(asyncio.IncompleteReadError) as cm:

with self.assertRaisesRegex(asyncio.IncompleteReadError,

'undefined expected bytes') as cm:

self.loop.run_until_complete(stream.readuntil(b'AAA'))

self.assertEqual(cm.exception.partial, b'some dataAA')

self.assertEqual(cm.exception.partial, data)

self.assertIsNone(cm.exception.expected)

self.assertEqual(b'', stream._buffer)

Clarify the error message for :exc:`asyncio.IncompleteReadError` when

``expected`` is ``None``.