Lib/test/test_mailbox.py

import os
import sys
import time
import stat
import socket
import email
import email.message
import re
import io
import tempfile
from test import support
import unittest
import textwrap
import mailbox
import glob
try:
    import fcntl
except ImportError:
    pass
try:
    import multiprocessing
except ImportError:
    multiprocessing = None


class TestBase(unittest.TestCase):

    def _check_sample(self, msg):
        # Inspect a mailbox.Message representation of the sample message
        self.assertIsInstance(msg, email.message.Message)
        self.assertIsInstance(msg, mailbox.Message)
        for key, value in _sample_headers.items():
            self.assertIn(value, msg.get_all(key))
        self.assertTrue(msg.is_multipart())
        self.assertEqual(len(msg.get_payload()), len(_sample_payloads))
        for i, payload in enumerate(_sample_payloads):
            part = msg.get_payload(i)
            self.assertIsInstance(part, email.message.Message)
            self.assertNotIsInstance(part, mailbox.Message)
            self.assertEqual(part.get_payload(), payload)

    def _delete_recursively(self, target):
        # Delete a file or delete a directory recursively
        if os.path.isdir(target):
            for path, dirs, files in os.walk(target, topdown=False):
                for name in files:
                    os.remove(os.path.join(path, name))
                for name in dirs:
                    os.rmdir(os.path.join(path, name))
            os.rmdir(target)
        elif os.path.exists(target):
            os.remove(target)


class TestMailbox(TestBase):

    maxDiff = None

    _factory = None     # Overridden by subclasses to reuse tests
    _template = 'From: foo\n\n%s'

    def setUp(self):
        self._path = support.TESTFN
        self._delete_recursively(self._path)
        self._box = self._factory(self._path)

    def tearDown(self):
        self._box.close()
        self._delete_recursively(self._path)

    def test_add(self):
        # Add copies of a sample message
        keys = []
        keys.append(self._box.add(self._template % 0))
        self.assertEqual(len(self._box), 1)
        keys.append(self._box.add(mailbox.Message(_sample_message)))
        self.assertEqual(len(self._box), 2)
        keys.append(self._box.add(email.message_from_string(_sample_message)))
        self.assertEqual(len(self._box), 3)
        keys.append(self._box.add(io.BytesIO(_bytes_sample_message)))
        self.assertEqual(len(self._box), 4)
        keys.append(self._box.add(_sample_message))
        self.assertEqual(len(self._box), 5)
        keys.append(self._box.add(_bytes_sample_message))
        self.assertEqual(len(self._box), 6)
        with self.assertWarns(DeprecationWarning):
            keys.append(self._box.add(
                io.TextIOWrapper(io.BytesIO(_bytes_sample_message))))
        self.assertEqual(len(self._box), 7)
        self.assertEqual(self._box.get_string(keys[0]), self._template % 0)
        for i in (1, 2, 3, 4, 5, 6):
            self._check_sample(self._box[keys[i]])

    _nonascii_msg = textwrap.dedent("""\
            From: foo
            Subject: Falinaptár házhozszállítással. Már rendeltél?

            0
            """)

    def test_add_invalid_8bit_bytes_header(self):
        key = self._box.add(self._nonascii_msg.encode('latin1'))
        self.assertEqual(len(self._box), 1)
        self.assertEqual(self._box.get_bytes(key),
            self._nonascii_msg.encode('latin1'))

    def test_invalid_nonascii_header_as_string(self):
        subj = self._nonascii_msg.splitlines()[1]
        key = self._box.add(subj.encode('latin1'))
        self.assertEqual(self._box.get_string(key),
            'Subject: =?unknown-8bit?b?RmFsaW5hcHThciBo4Xpob3pzeuFsbO104XNz'
            'YWwuIE3hciByZW5kZWx06Ww/?=\n\n')

    def test_add_nonascii_string_header_raises(self):
        with self.assertRaisesRegex(ValueError, "ASCII-only"):
            self._box.add(self._nonascii_msg)
        self._box.flush()
        self.assertEqual(len(self._box), 0)
        self.assertMailboxEmpty()

    def test_add_that_raises_leaves_mailbox_empty(self):
        # XXX This test will start failing when Message learns to handle
        # non-ASCII string headers, and a different internal failure will
        # need to be found or manufactured.
        with self.assertRaises(ValueError):
            self._box.add(email.message_from_string("From: Alphöso"))
        self.assertEqual(len(self._box), 0)
        self._box.close()
        self.assertMailboxEmpty()

    _non_latin_bin_msg = textwrap.dedent("""\
        From: foo@bar.com
        To: báz
        Subject: Maintenant je vous présente mon collègue, le pouf célèbre
        \tJean de Baddie
        Mime-Version: 1.0
        Content-Type: text/plain; charset="utf-8"
        Content-Transfer-Encoding: 8bit

        Да, они летят.
        """).encode('utf-8')

    def test_add_8bit_body(self):
        key = self._box.add(self._non_latin_bin_msg)
        self.assertEqual(self._box.get_bytes(key),
                         self._non_latin_bin_msg)
        with self._box.get_file(key) as f:
            self.assertEqual(f.read(),
                             self._non_latin_bin_msg.replace(b'\n',
                                os.linesep.encode()))
        self.assertEqual(self._box[key].get_payload(),
                        "Да, они летят.\n")

    def test_add_binary_file(self):
        with tempfile.TemporaryFile('wb+') as f:
            f.write(_bytes_sample_message)
            f.seek(0)
            key = self._box.add(f)
        # See issue 11062
        if not isinstance(self._box, mailbox.Babyl):
            self.assertEqual(self._box.get_bytes(key).split(b'\n'),
                _bytes_sample_message.split(b'\n'))

    def test_add_binary_nonascii_file(self):
        with tempfile.TemporaryFile('wb+') as f:
            f.write(self._non_latin_bin_msg)
            f.seek(0)
            key = self._box.add(f)
        # See issue 11062
        if not isinstance(self._box, mailbox.Babyl):
            self.assertEqual(self._box.get_bytes(key).split(b'\n'),
                self._non_latin_bin_msg.split(b'\n'))

    def test_add_text_file_warns(self):
        with tempfile.TemporaryFile('w+') as f:
            f.write(_sample_message)
            f.seek(0)
            with self.assertWarns(DeprecationWarning):
                key = self._box.add(f)
        # See issue 11062
        if not isinstance(self._box, mailbox.Babyl):
            self.assertEqual(self._box.get_bytes(key).split(b'\n'),
                _bytes_sample_message.split(b'\n'))

    def test_add_StringIO_warns(self):
        with self.assertWarns(DeprecationWarning):
            key = self._box.add(io.StringIO(self._template % "0"))
        self.assertEqual(self._box.get_string(key), self._template % "0")

    def test_add_nonascii_StringIO_raises(self):
        with self.assertWarns(DeprecationWarning):
            with self.assertRaisesRegex(ValueError, "ASCII-only"):
                self._box.add(io.StringIO(self._nonascii_msg))
        self.assertEqual(len(self._box), 0)
        self._box.close()
        self.assertMailboxEmpty()

    def test_remove(self):
        # Remove messages using remove()
        self._test_remove_or_delitem(self._box.remove)

    def test_delitem(self):
        # Remove messages using __delitem__()
        self._test_remove_or_delitem(self._box.__delitem__)

    def _test_remove_or_delitem(self, method):
        # (Used by test_remove() and test_delitem().)
        key0 = self._box.add(self._template % 0)
        key1 = self._box.add(self._template % 1)
        self.assertEqual(len(self._box), 2)
        method(key0)
        self.assertEqual(len(self._box), 1)
        self.assertRaises(KeyError, lambda: self._box[key0])
        self.assertRaises(KeyError, lambda: method(key0))
        self.assertEqual(self._box.get_string(key1), self._template % 1)
        key2 = self._box.add(self._template % 2)
        self.assertEqual(len(self._box), 2)
        method(key2)
        self.assertEqual(len(self._box), 1)
        self.assertRaises(KeyError, lambda: self._box[key2])
        self.assertRaises(KeyError, lambda: method(key2))
        self.assertEqual(self._box.get_string(key1), self._template % 1)
        method(key1)
        self.assertEqual(len(self._box), 0)
        self.assertRaises(KeyError, lambda: self._box[key1])
        self.assertRaises(KeyError, lambda: method(key1))

    def test_discard(self, repetitions=10):
        # Discard messages
        key0 = self._box.add(self._template % 0)
        key1 = self._box.add(self._template % 1)
        self.assertEqual(len(self._box), 2)
        self._box.discard(key0)
        self.assertEqual(len(self._box), 1)
        self.assertRaises(KeyError, lambda: self._box[key0])
        self._box.discard(key0)
        self.assertEqual(len(self._box), 1)
        self.assertRaises(KeyError, lambda: self._box[key0])

    def test_get(self):
        # Retrieve messages using get()
        key0 = self._box.add(self._template % 0)
        msg = self._box.get(key0)
        self.assertEqual(msg['from'], 'foo')
        self.assertEqual(msg.get_payload(), '0')
        self.assertIs(self._box.get('foo'), None)
        self.assertIs(self._box.get('foo', False), False)
        self._box.close()
        self._box = self._factory(self._path)
        key1 = self._box.add(self._template % 1)
        msg = self._box.get(key1)
        self.assertEqual(msg['from'], 'foo')
        self.assertEqual(msg.get_payload(), '1')

    def test_getitem(self):
        # Retrieve message using __getitem__()
        key0 = self._box.add(self._template % 0)
        msg = self._box[key0]
        self.assertEqual(msg['from'], 'foo')
        self.assertEqual(msg.get_payload(), '0')
        self.assertRaises(KeyError, lambda: self._box['foo'])
        self._box.discard(key0)
        self.assertRaises(KeyError, lambda: self._box[key0])

    def test_get_message(self):
        # Get Message representations of messages
        key0 = self._box.add(self._template % 0)
        key1 = self._box.add(_sample_message)
        msg0 = self._box.get_message(key0)
        self.assertIsInstance(msg0, mailbox.Message)
        self.assertEqual(msg0['from'], 'foo')
        self.assertEqual(msg0.get_payload(), '0')
        self._check_sample(self._box.get_message(key1))

    def test_get_bytes(self):
        # Get bytes representations of messages
        key0 = self._box.add(self._template % 0)
        key1 = self._box.add(_sample_message)
        self.assertEqual(self._box.get_bytes(key0),
            (self._template % 0).encode('ascii'))
        self.assertEqual(self._box.get_bytes(key1), _bytes_sample_message)

    def test_get_string(self):
        # Get string representations of messages
        key0 = self._box.add(self._template % 0)
        key1 = self._box.add(_sample_message)
        self.assertEqual(self._box.get_string(key0), self._template % 0)
        self.assertEqual(self._box.get_string(key1).split('\n'),
                         _sample_message.split('\n'))

    def test_get_file(self):
        # Get file representations of messages
        key0 = self._box.add(self._template % 0)
        key1 = self._box.add(_sample_message)
        with self._box.get_file(key0) as file:
            data0 = file.read()
        with self._box.get_file(key1) as file:
            data1 = file.read()
        self.assertEqual(data0.decode('ascii').replace(os.linesep, '\n'),
                         self._template % 0)
        self.assertEqual(data1.decode('ascii').replace(os.linesep, '\n'),
                         _sample_message)

    def test_get_file_can_be_closed_twice(self):
        # Issue 11700
        key = self._box.add(_sample_message)
        f = self._box.get_file(key)
        f.close()
        f.close()

    def test_iterkeys(self):
        # Get keys using iterkeys()
        self._check_iteration(self._box.keys, do_keys=True, do_values=False)

    def test_keys(self):
        # Get keys using keys()
        self._check_iteration(self._box.keys, do_keys=True, do_values=False)

    def test_itervalues(self):
        # Get values using itervalues()
        self._check_iteration(self._box.values, do_keys=False,
                              do_values=True)

    def test_iter(self):
        # Get values using __iter__()
        self._check_iteration(self._box.__iter__, do_keys=False,
                              do_values=True)

    def test_values(self):
        # Get values using values()
        self._check_iteration(self._box.values, do_keys=False, do_values=True)

    def test_iteritems(self):
        # Get keys and values using iteritems()
        self._check_iteration(self._box.items, do_keys=True,
                              do_values=True)

    def test_items(self):
        # Get keys and values using items()
        self._check_iteration(self._box.items, do_keys=True, do_values=True)

    def _check_iteration(self, method, do_keys, do_values, repetitions=10):
        for value in method():
            self.fail("Not empty")
        keys, values = [], []
        for i in range(repetitions):
            keys.append(self._box.add(self._template % i))
            values.append(self._template % i)
        if do_keys and not do_values:
            returned_keys = list(method())
        elif do_values and not do_keys:
            returned_values = list(method())
        else:
            returned_keys, returned_values = [], []
            for key, value in method():
                returned_keys.append(key)
                returned_values.append(value)
        if do_keys:
            self.assertEqual(len(keys), len(returned_keys))
            self.assertEqual(set(keys), set(returned_keys))
        if do_values:
            count = 0
            for value in returned_values:
                self.assertEqual(value['from'], 'foo')
                self.assertLess(int(value.get_payload()), repetitions)
                count += 1
            self.assertEqual(len(values), count)

    def test_contains(self):
        # Check existence of keys using __contains__()
        self.assertNotIn('foo', self._box)
        key0 = self._box.add(self._template % 0)
        self.assertIn(key0, self._box)
        self.assertNotIn('foo', self._box)
        key1 = self._box.add(self._template % 1)
        self.assertIn(key1, self._box)
        self.assertIn(key0, self._box)
        self.assertNotIn('foo', self._box)
        self._box.remove(key0)
        self.assertNotIn(key0, self._box)
        self.assertIn(key1, self._box)
        self.assertNotIn('foo', self._box)
        self._box.remove(key1)
        self.assertNotIn(key1, self._box)
        self.assertNotIn(key0, self._box)
        self.assertNotIn('foo', self._box)

    def test_len(self, repetitions=10):
        # Get message count
        keys = []
        for i in range(repetitions):
            self.assertEqual(len(self._box), i)
            keys.append(self._box.add(self._template % i))
            self.assertEqual(len(self._box), i + 1)
        for i in range(repetitions):
            self.assertEqual(len(self._box), repetitions - i)
            self._box.remove(keys[i])
            self.assertEqual(len(self._box), repetitions - i - 1)

    def test_set_item(self):
        # Modify messages using __setitem__()
        key0 = self._box.add(self._template % 'original 0')
        self.assertEqual(self._box.get_string(key0),
                         self._template % 'original 0')
        key1 = self._box.add(self._template % 'original 1')
        self.assertEqual(self._box.get_string(key1),
                         self._template % 'original 1')
        self._box[key0] = self._template % 'changed 0'
        self.assertEqual(self._box.get_string(key0),
                         self._template % 'changed 0')
        self._box[key1] = self._template % 'changed 1'
        self.assertEqual(self._box.get_string(key1),
                         self._template % 'changed 1')
        self._box[key0] = _sample_message
        self._check_sample(self._box[key0])
        self._box[key1] = self._box[key0]
        self._check_sample(self._box[key1])
        self._box[key0] = self._template % 'original 0'
        self.assertEqual(self._box.get_string(key0),
                     self._template % 'original 0')
        self._check_sample(self._box[key1])
        self.assertRaises(KeyError,
                          lambda: self._box.__setitem__('foo', 'bar'))
        self.assertRaises(KeyError, lambda: self._box['foo'])
        self.assertEqual(len(self._box), 2)

    def test_clear(self, iterations=10):
        # Remove all messages using clear()
        keys = []
        for i in range(iterations):
            self._box.add(self._template % i)
        for i, key in enumerate(keys):
            self.assertEqual(self._box.get_string(key), self._template % i)
        self._box.clear()
        self.assertEqual(len(self._box), 0)
        for i, key in enumerate(keys):
            self.assertRaises(KeyError, lambda: self._box.get_string(key))

    def test_pop(self):
        # Get and remove a message using pop()
        key0 = self._box.add(self._template % 0)
        self.assertIn(key0, self._box)
        key1 = self._box.add(self._template % 1)
        self.assertIn(key1, self._box)
        self.assertEqual(self._box.pop(key0).get_payload(), '0')
        self.assertNotIn(key0, self._box)
        self.assertIn(key1, self._box)
        key2 = self._box.add(self._template % 2)
        self.assertIn(key2, self._box)
        self.assertEqual(self._box.pop(key2).get_payload(), '2')
        self.assertNotIn(key2, self._box)
        self.assertIn(key1, self._box)
        self.assertEqual(self._box.pop(key1).get_payload(), '1')
        self.assertNotIn(key1, self._box)
        self.assertEqual(len(self._box), 0)

    def test_popitem(self, iterations=10):
        # Get and remove an arbitrary (key, message) using popitem()
        keys = []
        for i in range(10):
            keys.append(self._box.add(self._template % i))
        seen = []
        for i in range(10):
            key, msg = self._box.popitem()
            self.assertIn(key, keys)
            self.assertNotIn(key, seen)
            seen.append(key)
            self.assertEqual(int(msg.get_payload()), keys.index(key))
        self.assertEqual(len(self._box), 0)
        for key in keys:
            self.assertRaises(KeyError, lambda: self._box[key])

    def test_update(self):
        # Modify multiple messages using update()
        key0 = self._box.add(self._template % 'original 0')
        key1 = self._box.add(self._template % 'original 1')
        key2 = self._box.add(self._template % 'original 2')
        self._box.update({key0: self._template % 'changed 0',
                          key2: _sample_message})
        self.assertEqual(len(self._box), 3)
        self.assertEqual(self._box.get_string(key0),
                     self._template % 'changed 0')
        self.assertEqual(self._box.get_string(key1),
                     self._template % 'original 1')
        self._check_sample(self._box[key2])
        self._box.update([(key2, self._template % 'changed 2'),
                    (key1, self._template % 'changed 1'),
                    (key0, self._template % 'original 0')])
        self.assertEqual(len(self._box), 3)
        self.assertEqual(self._box.get_string(key0),
                     self._template % 'original 0')
        self.assertEqual(self._box.get_string(key1),
                     self._template % 'changed 1')
        self.assertEqual(self._box.get_string(key2),
                     self._template % 'changed 2')
        self.assertRaises(KeyError,
                          lambda: self._box.update({'foo': 'bar',
                                          key0: self._template % "changed 0"}))
        self.assertEqual(len(self._box), 3)
        self.assertEqual(self._box.get_string(key0),
                     self._template % "changed 0")
        self.assertEqual(self._box.get_string(key1),
                     self._template % "changed 1")
        self.assertEqual(self._box.get_string(key2),
                     self._template % "changed 2")

    def test_flush(self):
        # Write changes to disk
        self._test_flush_or_close(self._box.flush, True)

    def test_lock_unlock(self):
        # Lock and unlock the mailbox
        self.assertFalse(os.path.exists(self._get_lock_path()))
        self._box.lock()
        self.assertTrue(os.path.exists(self._get_lock_path()))
        self._box.unlock()
        self.assertFalse(os.path.exists(self._get_lock_path()))

    def test_close(self):
        # Close mailbox and flush changes to disk
        self._test_flush_or_close(self._box.close, False)

    def _test_flush_or_close(self, method, should_call_close):
        contents = [self._template % i for i in range(3)]
        self._box.add(contents[0])
        self._box.add(contents[1])
        self._box.add(contents[2])
        oldbox = self._box
        method()
        if should_call_close:
            self._box.close()
        self._box = self._factory(self._path)
        keys = self._box.keys()
        self.assertEqual(len(keys), 3)
        for key in keys:
            self.assertIn(self._box.get_string(key), contents)
        oldbox.close()

    def test_dump_message(self):
        # Write message representations to disk
        for input in (email.message_from_string(_sample_message),
                      _sample_message, io.BytesIO(_bytes_sample_message)):
            output = io.BytesIO()
            self._box._dump_message(input, output)
            self.assertEqual(output.getvalue(),
                _bytes_sample_message.replace(b'\n', os.linesep.encode()))
        output = io.BytesIO()
        self.assertRaises(TypeError,
                          lambda: self._box._dump_message(None, output))

    def _get_lock_path(self):
        # Return the path of the dot lock file. May be overridden.
        return self._path + '.lock'


class TestMailboxSuperclass(TestBase):

    def test_notimplemented(self):
        # Test that all Mailbox methods raise NotImplementedException.
        box = mailbox.Mailbox('path')
        self.assertRaises(NotImplementedError, lambda: box.add(''))
        self.assertRaises(NotImplementedError, lambda: box.remove(''))
        self.assertRaises(NotImplementedError, lambda: box.__delitem__(''))
        self.assertRaises(NotImplementedError, lambda: box.discard(''))
        self.assertRaises(NotImplementedError, lambda: box.__setitem__('', ''))
        self.assertRaises(NotImplementedError, lambda: box.keys())
        self.assertRaises(NotImplementedError, lambda: box.keys())
        self.assertRaises(NotImplementedError, lambda: box.values().__next__())
        self.assertRaises(NotImplementedError, lambda: box.__iter__().__next__())
        self.assertRaises(NotImplementedError, lambda: box.values())
        self.assertRaises(NotImplementedError, lambda: box.items().next())
        self.assertRaises(NotImplementedError, lambda: box.items())
        self.assertRaises(NotImplementedError, lambda: box.get(''))
        self.assertRaises(NotImplementedError, lambda: box.__getitem__(''))
        self.assertRaises(NotImplementedError, lambda: box.get_message(''))
        self.assertRaises(NotImplementedError, lambda: box.get_string(''))
        self.assertRaises(NotImplementedError, lambda: box.get_bytes(''))
        self.assertRaises(NotImplementedError, lambda: box.get_file(''))
        self.assertRaises(NotImplementedError, lambda: '' in box)
        self.assertRaises(NotImplementedError, lambda: box.__contains__(''))
        self.assertRaises(NotImplementedError, lambda: box.__len__())
        self.assertRaises(NotImplementedError, lambda: box.clear())
        self.assertRaises(NotImplementedError, lambda: box.pop(''))
        self.assertRaises(NotImplementedError, lambda: box.popitem())
        self.assertRaises(NotImplementedError, lambda: box.update((('', ''),)))
        self.assertRaises(NotImplementedError, lambda: box.flush())
        self.assertRaises(NotImplementedError, lambda: box.lock())
        self.assertRaises(NotImplementedError, lambda: box.unlock())
        self.assertRaises(NotImplementedError, lambda: box.close())


class TestMaildir(TestMailbox):

    _factory = lambda self, path, factory=None: mailbox.Maildir(path, factory)

    def setUp(self):
        TestMailbox.setUp(self)
        if os.name in ('nt', 'os2') or sys.platform == 'cygwin':
            self._box.colon = '!'

    def assertMailboxEmpty(self):
        self.assertEqual(os.listdir(os.path.join(self._path, 'tmp')), [])

    def test_add_MM(self):
        # Add a MaildirMessage instance
        msg = mailbox.MaildirMessage(self._template % 0)
        msg.set_subdir('cur')
        msg.set_info('foo')
        key = self._box.add(msg)
        self.assertTrue(os.path.exists(os.path.join(self._path, 'cur', '%s%sfoo' %
                                                 (key, self._box.colon))))

    def test_get_MM(self):
        # Get a MaildirMessage instance
        msg = mailbox.MaildirMessage(self._template % 0)
        msg.set_subdir('cur')
        msg.set_flags('RF')
        key = self._box.add(msg)
        msg_returned = self._box.get_message(key)
        self.assertIsInstance(msg_returned, mailbox.MaildirMessage)
        self.assertEqual(msg_returned.get_subdir(), 'cur')
        self.assertEqual(msg_returned.get_flags(), 'FR')

    def test_set_MM(self):
        # Set with a MaildirMessage instance
        msg0 = mailbox.MaildirMessage(self._template % 0)
        msg0.set_flags('TP')
        key = self._box.add(msg0)
        msg_returned = self._box.get_message(key)
        self.assertEqual(msg_returned.get_subdir(), 'new')
        self.assertEqual(msg_returned.get_flags(), 'PT')
        msg1 = mailbox.MaildirMessage(self._template % 1)
        self._box[key] = msg1
        msg_returned = self._box.get_message(key)
        self.assertEqual(msg_returned.get_subdir(), 'new')
        self.assertEqual(msg_returned.get_flags(), '')
        self.assertEqual(msg_returned.get_payload(), '1')
        msg2 = mailbox.MaildirMessage(self._template % 2)
        msg2.set_info('2,S')
        self._box[key] = msg2
        self._box[key] = self._template % 3
        msg_returned = self._box.get_message(key)
        self.assertEqual(msg_returned.get_subdir(), 'new')
        self.assertEqual(msg_returned.get_flags(), 'S')
        self.assertEqual(msg_returned.get_payload(), '3')

    def test_consistent_factory(self):
        # Add a message.
        msg = mailbox.MaildirMessage(self._template % 0)
        msg.set_subdir('cur')
        msg.set_flags('RF')
        key = self._box.add(msg)

        # Create new mailbox with
        class FakeMessage(mailbox.MaildirMessage):
            pass
        box = mailbox.Maildir(self._path, factory=FakeMessage)
        box.colon = self._box.colon
        msg2 = box.get_message(key)
        self.assertIsInstance(msg2, FakeMessage)

    def test_initialize_new(self):
        # Initialize a non-existent mailbox
        self.tearDown()
        self._box = mailbox.Maildir(self._path)
        self._check_basics()
        self._delete_recursively(self._path)
        self._box = self._factory(self._path, factory=None)
        self._check_basics()

    def test_initialize_existing(self):
        # Initialize an existing mailbox
        self.tearDown()
        for subdir in '', 'tmp', 'new', 'cur':
            os.mkdir(os.path.normpath(os.path.join(self._path, subdir)))
        self._box = mailbox.Maildir(self._path)
        self._check_basics()

    def _check_basics(self, factory=None):
        # (Used by test_open_new() and test_open_existing().)
        self.assertEqual(self._box._path, os.path.abspath(self._path))
        self.assertEqual(self._box._factory, factory)
        for subdir in '', 'tmp', 'new', 'cur':
            path = os.path.join(self._path, subdir)
            mode = os.stat(path)[stat.ST_MODE]
            self.assertTrue(stat.S_ISDIR(mode), "Not a directory: '%s'" % path)

    def test_list_folders(self):
        # List folders
        self._box.add_folder('one')
        self._box.add_folder('two')
        self._box.add_folder('three')
        self.assertEqual(len(self._box.list_folders()), 3)
        self.assertEqual(set(self._box.list_folders()),
                     set(('one', 'two', 'three')))

    def test_get_folder(self):
        # Open folders
        self._box.add_folder('foo.bar')
        folder0 = self._box.get_folder('foo.bar')
        folder0.add(self._template % 'bar')
        self.assertTrue(os.path.isdir(os.path.join(self._path, '.foo.bar')))
        folder1 = self._box.get_folder('foo.bar')
        self.assertEqual(folder1.get_string(folder1.keys()[0]),
                         self._template % 'bar')

    def test_add_and_remove_folders(self):
        # Delete folders
        self._box.add_folder('one')
        self._box.add_folder('two')
        self.assertEqual(len(self._box.list_folders()), 2)
        self.assertEqual(set(self._box.list_folders()), set(('one', 'two')))
        self._box.remove_folder('one')
        self.assertEqual(len(self._box.list_folders()), 1)
        self.assertEqual(set(self._box.list_folders()), set(('two',)))
        self._box.add_folder('three')
        self.assertEqual(len(self._box.list_folders()), 2)
        self.assertEqual(set(self._box.list_folders()), set(('two', 'three')))
        self._box.remove_folder('three')
        self.assertEqual(len(self._box.list_folders()), 1)
        self.assertEqual(set(self._box.list_folders()), set(('two',)))
        self._box.remove_folder('two')
        self.assertEqual(len(self._box.list_folders()), 0)
        self.assertEqual(self._box.list_folders(), [])

    def test_clean(self):
        # Remove old files from 'tmp'
        foo_path = os.path.join(self._path, 'tmp', 'foo')
        bar_path = os.path.join(self._path, 'tmp', 'bar')
        with open(foo_path, 'w') as f:
            f.write("@")
        with open(bar_path, 'w') as f:
            f.write("@")
        self._box.clean()
        self.assertTrue(os.path.exists(foo_path))
        self.assertTrue(os.path.exists(bar_path))
        foo_stat = os.stat(foo_path)
        os.utime(foo_path, (time.time() - 129600 - 2,
                            foo_stat.st_mtime))
        self._box.clean()
        self.assertFalse(os.path.exists(foo_path))
        self.assertTrue(os.path.exists(bar_path))

    def test_create_tmp(self, repetitions=10):
        # Create files in tmp directory
        hostname = socket.gethostname()
        if '/' in hostname:
            hostname = hostname.replace('/', r'\057')
        if ':' in hostname:
            hostname = hostname.replace(':', r'\072')
        pid = os.getpid()
        pattern = re.compile(r"(?P<time>\d+)\.M(?P<M>\d{1,6})P(?P<P>\d+)"
                             r"Q(?P<Q>\d+)\.(?P<host>[^:/]+)")
        previous_groups = None
        for x in range(repetitions):
            tmp_file = self._box._create_tmp()
            head, tail = os.path.split(tmp_file.name)
            self.assertEqual(head, os.path.abspath(os.path.join(self._path,
                                                                "tmp")),
                             "File in wrong location: '%s'" % head)
            match = pattern.match(tail)
            self.assertIsNot(match, None, "Invalid file name: '%s'" % tail)
            groups = match.groups()
            if previous_groups is not None:
                self.assertTrue(int(groups[0] >= previous_groups[0]),
                             "Non-monotonic seconds: '%s' before '%s'" %
                             (previous_groups[0], groups[0]))
                self.assertTrue(int(groups[1] >= previous_groups[1]) or
                             groups[0] != groups[1],
                             "Non-monotonic milliseconds: '%s' before '%s'" %
                             (previous_groups[1], groups[1]))
                self.assertEqual(int(groups[2]), pid,
                             "Process ID mismatch: '%s' should be '%s'" %
                             (groups[2], pid))
                self.assertEqual(int(groups[3]), int(previous_groups[3]) + 1,
                             "Non-sequential counter: '%s' before '%s'" %
                             (previous_groups[3], groups[3]))
                self.assertEqual(groups[4], hostname,
                             "Host name mismatch: '%s' should be '%s'" %
                             (groups[4], hostname))
            previous_groups = groups
            tmp_file.write(_bytes_sample_message)
            tmp_file.seek(0)
            self.assertEqual(tmp_file.read(), _bytes_sample_message)
            tmp_file.close()
        file_count = len(os.listdir(os.path.join(self._path, "tmp")))
        self.assertEqual(file_count, repetitions,
                     "Wrong file count: '%s' should be '%s'" %
                     (file_count, repetitions))

    def test_refresh(self):
        # Update the table of contents
        self.assertEqual(self._box._toc, {})
        key0 = self._box.add(self._template % 0)
        key1 = self._box.add(self._template % 1)
        self.assertEqual(self._box._toc, {})
        self._box._refresh()
        self.assertEqual(self._box._toc, {key0: os.path.join('new', key0),
                                          key1: os.path.join('new', key1)})
        key2 = self._box.add(self._template % 2)
        self.assertEqual(self._box._toc, {key0: os.path.join('new', key0),
                                          key1: os.path.join('new', key1)})
        self._box._refresh()
        self.assertEqual(self._box._toc, {key0: os.path.join('new', key0),
                                          key1: os.path.join('new', key1),
                                          key2: os.path.join('new', key2)})

    def test_refresh_after_safety_period(self):
        # Issue #13254: Call _refresh after the "file system safety
        # period" of 2 seconds has passed; _toc should still be
        # updated because this is the first call to _refresh.
        key0 = self._box.add(self._template % 0)
        key1 = self._box.add(self._template % 1)

        self._box = self._factory(self._path)
        self.assertEqual(self._box._toc, {})

        # Emulate sleeping. Instead of sleeping for 2 seconds, use the
        # skew factor to make _refresh think that the filesystem
        # safety period has passed and re-reading the _toc is only
        # required if mtimes differ.
        self._box._skewfactor = -3

        self._box._refresh()
        self.assertEqual(sorted(self._box._toc.keys()), sorted([key0, key1]))

    def test_lookup(self):
        # Look up message subpaths in the TOC
        self.assertRaises(KeyError, lambda: self._box._lookup('foo'))
        key0 = self._box.add(self._template % 0)
        self.assertEqual(self._box._lookup(key0), os.path.join('new', key0))
        os.remove(os.path.join(self._path, 'new', key0))
        self.assertEqual(self._box._toc, {key0: os.path.join('new', key0)})
        # Be sure that the TOC is read back from disk (see issue #6896
        # about bad mtime behaviour on some systems).
        self._box.flush()
        self.assertRaises(KeyError, lambda: self._box._lookup(key0))
        self.assertEqual(self._box._toc, {})

    def test_lock_unlock(self):
        # Lock and unlock the mailbox. For Maildir, this does nothing.
        self._box.lock()
        self._box.unlock()

    def test_folder (self):
        # Test for bug #1569790: verify that folders returned by .get_folder()
        # use the same factory function.
        def dummy_factory (s):
            return None
        box = self._factory(self._path, factory=dummy_factory)
        folder = box.add_folder('folder1')
        self.assertIs(folder._factory, dummy_factory)

        folder1_alias = box.get_folder('folder1')
        self.assertIs(folder1_alias._factory, dummy_factory)

    def test_directory_in_folder (self):
        # Test that mailboxes still work if there's a stray extra directory
        # in a folder.
        for i in range(10):
            self._box.add(mailbox.Message(_sample_message))

        # Create a stray directory
        os.mkdir(os.path.join(self._path, 'cur', 'stray-dir'))

        # Check that looping still works with the directory present.
        for msg in self._box:
            pass

    def test_file_permissions(self):
        # Verify that message files are created without execute permissions
        if not hasattr(os, "stat") or not hasattr(os, "umask"):
            return
        msg = mailbox.MaildirMessage(self._template % 0)
        orig_umask = os.umask(0)
        try:
            key = self._box.add(msg)
        finally:
            os.umask(orig_umask)
        path = os.path.join(self._path, self._box._lookup(key))
        mode = os.stat(path).st_mode
        self.assertFalse(mode & 0o111)

    def test_folder_file_perms(self):
        # From bug #3228, we want to verify that the file created inside a Maildir
        # subfolder isn't marked as executable.
        if not hasattr(os, "stat") or not hasattr(os, "umask"):
            return

        orig_umask = os.umask(0)
        try:
            subfolder = self._box.add_folder('subfolder')
        finally:
            os.umask(orig_umask)

        path = os.path.join(subfolder._path, 'maildirfolder')
        st = os.stat(path)
        perms = st.st_mode
        self.assertFalse((perms & 0o111)) # Execute bits should all be off.

    def test_reread(self):
        # Do an initial unconditional refresh
        self._box._refresh()

        # Put the last modified times more than two seconds into the past
        # (because mtime may have a two second granularity)
        for subdir in ('cur', 'new'):
            os.utime(os.path.join(self._box._path, subdir),
                     (time.time()-5,)*2)

        # Because mtime has a two second granularity in worst case (FAT), a
        # refresh is done unconditionally if called for within
        # two-second-plus-a-bit of the last one, just in case the mbox has
        # changed; so now we have to wait for that interval to expire.
        #
        # Because this is a test, emulate sleeping. Instead of
        # sleeping for 2 seconds, use the skew factor to make _refresh
        # think that 2 seconds have passed and re-reading the _toc is
        # only required if mtimes differ.
        self._box._skewfactor = -3

        # Re-reading causes the ._toc attribute to be assigned a new dictionary
        # object, so we'll check that the ._toc attribute isn't a different
        # object.
        orig_toc = self._box._toc
        def refreshed():
            return self._box._toc is not orig_toc

        self._box._refresh()
        self.assertFalse(refreshed())

        # Now, write something into cur and remove it.  This changes
        # the mtime and should cause a re-read. Note that "sleep
        # emulation" is still in effect, as skewfactor is -3.
        filename = os.path.join(self._path, 'cur', 'stray-file')
        f = open(filename, 'w')
        f.close()
        os.unlink(filename)
        self._box._refresh()
        self.assertTrue(refreshed())

class _TestMboxMMDF(TestMailbox):

    def tearDown(self):
        super().tearDown()
        self._box.close()
        self._delete_recursively(self._path)
        for lock_remnant in glob.glob(self._path + '.*'):
            support.unlink(lock_remnant)

    def assertMailboxEmpty(self):
        with open(self._path) as f:
            self.assertEqual(f.readlines(), [])

    def test_add_from_string(self):
        # Add a string starting with 'From ' to the mailbox
        key = self._box.add('From foo@bar blah\nFrom: foo\n\n0')
        self.assertEqual(self._box[key].get_from(), 'foo@bar blah')
        self.assertEqual(self._box[key].get_payload(), '0')

    def test_add_from_bytes(self):
        # Add a byte string starting with 'From ' to the mailbox
        key = self._box.add(b'From foo@bar blah\nFrom: foo\n\n0')
        self.assertEqual(self._box[key].get_from(), 'foo@bar blah')
        self.assertEqual(self._box[key].get_payload(), '0')

    def test_add_mbox_or_mmdf_message(self):
        # Add an mboxMessage or MMDFMessage
        for class_ in (mailbox.mboxMessage, mailbox.MMDFMessage):
            msg = class_('From foo@bar blah\nFrom: foo\n\n0')
            key = self._box.add(msg)

    def test_open_close_open(self):
        # Open and inspect previously-created mailbox
        values = [self._template % i for i in range(3)]
        for value in values:
            self._box.add(value)
        self._box.close()
        mtime = os.path.getmtime(self._path)
        self._box = self._factory(self._path)
        self.assertEqual(len(self._box), 3)
        for key in self._box.keys():
            self.assertIn(self._box.get_string(key), values)
        self._box.close()
        self.assertEqual(mtime, os.path.getmtime(self._path))

    def test_add_and_close(self):
        # Verifying that closing a mailbox doesn't change added items
        self._box.add(_sample_message)
        for i in range(3):
            self._box.add(self._template % i)
        self._box.add(_sample_message)
        self._box._file.flush()
        self._box._file.seek(0)
        contents = self._box._file.read()
        self._box.close()
        with open(self._path, 'rb') as f:
            self.assertEqual(contents, f.read())
        self._box = self._factory(self._path)

    @unittest.skipUnless(hasattr(os, 'fork'), "Test needs fork().")
    @unittest.skipUnless(multiprocessing, "Test needs multiprocessing.")
    def test_lock_conflict(self):
        # Fork off a child process that will lock the mailbox temporarily,
        # unlock it and exit.
        ready = multiprocessing.Event()
        done = multiprocessing.Event()

        pid = os.fork()
        if pid == 0:
            # child
            try:
                # lock the mailbox, and signal the parent it can proceed
                self._box.lock()
                ready.set()

                # wait until the parent is done, and unlock the mailbox
                done.wait(5)
                self._box.unlock()
            finally:
                os._exit(0)

        # In the parent, wait until the child signals it locked the mailbox.
        ready.wait(5)
        try:
            self.assertRaises(mailbox.ExternalClashError,
                              self._box.lock)
        finally:
            # Signal the child it can now release the lock and exit.
            done.set()
            # Wait for child to exit.  Locking should now succeed.
            exited_pid, status = os.waitpid(pid, 0)

        self._box.lock()
        self._box.unlock()

    def test_relock(self):
        # Test case for bug #1575506: the mailbox class was locking the
        # wrong file object in its flush() method.
        msg = "Subject: sub\n\nbody\n"
        key1 = self._box.add(msg)
        self._box.flush()
        self._box.close()

        self._box = self._factory(self._path)
        self._box.lock()
        key2 = self._box.add(msg)
        self._box.flush()
        self.assertTrue(self._box._locked)
        self._box.close()


class TestMbox(_TestMboxMMDF):

    _factory = lambda self, path, factory=None: mailbox.mbox(path, factory)

    def test_file_perms(self):
        # From bug #3228, we want to verify that the mailbox file isn't executable,
        # even if the umask is set to something that would leave executable bits set.
        # We only run this test on platforms that support umask.
        if hasattr(os, 'umask') and hasattr(os, 'stat'):
            try:
                old_umask = os.umask(0o077)
                self._box.close()
                os.unlink(self._path)
                self._box = mailbox.mbox(self._path, create=True)
                self._box.add('')
                self._box.close()
            finally:
                os.umask(old_umask)

            st = os.stat(self._path)
            perms = st.st_mode
            self.assertFalse((perms & 0o111)) # Execute bits should all be off.

class TestMMDF(_TestMboxMMDF):

    _factory = lambda self, path, factory=None: mailbox.MMDF(path, factory)


class TestMH(TestMailbox):

    _factory = lambda self, path, factory=None: mailbox.MH(path, factory)

    def assertMailboxEmpty(self):
        self.assertEqual(os.listdir(self._path), ['.mh_sequences'])

    def test_list_folders(self):
        # List folders
        self._box.add_folder('one')
        self._box.add_folder('two')
        self._box.add_folder('three')
        self.assertEqual(len(self._box.list_folders()), 3)
        self.assertEqual(set(self._box.list_folders()),
                     set(('one', 'two', 'three')))

    def test_get_folder(self):
        # Open folders
        def dummy_factory (s):
            return None
        self._box = self._factory(self._path, dummy_factory)

        new_folder = self._box.add_folder('foo.bar')
        folder0 = self._box.get_folder('foo.bar')
        folder0.add(self._template % 'bar')
        self.assertTrue(os.path.isdir(os.path.join(self._path, 'foo.bar')))
        folder1 = self._box.get_folder('foo.bar')
        self.assertEqual(folder1.get_string(folder1.keys()[0]),
                         self._template % 'bar')

        # Test for bug #1569790: verify that folders returned by .get_folder()
        # use the same factory function.
        self.assertIs(new_folder._factory, self._box._factory)
        self.assertIs(folder0._factory, self._box._factory)

    def test_add_and_remove_folders(self):
        # Delete folders
        self._box.add_folder('one')
        self._box.add_folder('two')
        self.assertEqual(len(self._box.list_folders()), 2)
        self.assertEqual(set(self._box.list_folders()), set(('one', 'two')))
        self._box.remove_folder('one')
        self.assertEqual(len(self._box.list_folders()), 1)
        self.assertEqual(set(self._box.list_folders()), set(('two',)))
        self._box.add_folder('three')
        self.assertEqual(len(self._box.list_folders()), 2)
        self.assertEqual(set(self._box.list_folders()), set(('two', 'three')))
        self._box.remove_folder('three')
        self.assertEqual(len(self._box.list_folders()), 1)
        self.assertEqual(set(self._box.list_folders()), set(('two',)))
        self._box.remove_folder('two')
        self.assertEqual(len(self._box.list_folders()), 0)
        self.assertEqual(self._box.list_folders(), [])

    def test_sequences(self):
        # Get and set sequences
        self.assertEqual(self._box.get_sequences(), {})
        msg0 = mailbox.MHMessage(self._template % 0)
        msg0.add_sequence('foo')
        key0 = self._box.add(msg0)
        self.assertEqual(self._box.get_sequences(), {'foo':[key0]})
        msg1 = mailbox.MHMessage(self._template % 1)
        msg1.set_sequences(['bar', 'replied', 'foo'])
        key1 = self._box.add(msg1)
        self.assertEqual(self._box.get_sequences(),
                     {'foo':[key0, key1], 'bar':[key1], 'replied':[key1]})
        msg0.set_sequences(['flagged'])
        self._box[key0] = msg0
        self.assertEqual(self._box.get_sequences(),
                     {'foo':[key1], 'bar':[key1], 'replied':[key1],
                      'flagged':[key0]})
        self._box.remove(key1)
        self.assertEqual(self._box.get_sequences(), {'flagged':[key0]})

    def test_issue2625(self):
        msg0 = mailbox.MHMessage(self._template % 0)
        msg0.add_sequence('foo')
        key0 = self._box.add(msg0)
        refmsg0 = self._box.get_message(key0)

    def test_issue7627(self):
        msg0 = mailbox.MHMessage(self._template % 0)
        key0 = self._box.add(msg0)
        self._box.lock()
        self._box.remove(key0)
        self._box.unlock()

    def test_pack(self):
        # Pack the contents of the mailbox
        msg0 = mailbox.MHMessage(self._template % 0)
        msg1 = mailbox.MHMessage(self._template % 1)
        msg2 = mailbox.MHMessage(self._template % 2)
        msg3 = mailbox.MHMessage(self._template % 3)
        msg0.set_sequences(['foo', 'unseen'])
        msg1.set_sequences(['foo'])
        msg2.set_sequences(['foo', 'flagged'])
        msg3.set_sequences(['foo', 'bar', 'replied'])
        key0 = self._box.add(msg0)
        key1 = self._box.add(msg1)
        key2 = self._box.add(msg2)
        key3 = self._box.add(msg3)
        self.assertEqual(self._box.get_sequences(),
                     {'foo':[key0,key1,key2,key3], 'unseen':[key0],
                      'flagged':[key2], 'bar':[key3], 'replied':[key3]})
        self._box.remove(key2)
        self.assertEqual(self._box.get_sequences(),
                     {'foo':[key0,key1,key3], 'unseen':[key0], 'bar':[key3],
                      'replied':[key3]})
        self._box.pack()
        self.assertEqual(self._box.keys(), [1, 2, 3])
        key0 = key0
        key1 = key0 + 1
        key2 = key1 + 1
        self.assertEqual(self._box.get_sequences(),
                     {'foo':[1, 2, 3], 'unseen':[1], 'bar':[3], 'replied':[3]})

        # Test case for packing while holding the mailbox locked.
        key0 = self._box.add(msg1)
        key1 = self._box.add(msg1)
        key2 = self._box.add(msg1)
        key3 = self._box.add(msg1)

        self._box.remove(key0)
        self._box.remove(key2)
        self._box.lock()
        self._box.pack()
        self._box.unlock()
        self.assertEqual(self._box.get_sequences(),
                     {'foo':[1, 2, 3, 4, 5],
                      'unseen':[1], 'bar':[3], 'replied':[3]})

    def _get_lock_path(self):
        return os.path.join(self._path, '.mh_sequences.lock')


class TestBabyl(TestMailbox):

    _factory = lambda self, path, factory=None: mailbox.Babyl(path, factory)

    def assertMailboxEmpty(self):
        with open(self._path) as f:
            self.assertEqual(f.readlines(), [])

    def tearDown(self):
        super().tearDown()
        self._box.close()
        self._delete_recursively(self._path)
        for lock_remnant in glob.glob(self._path + '.*'):
            support.unlink(lock_remnant)

    def test_labels(self):
        # Get labels from the mailbox
        self.assertEqual(self._box.get_labels(), [])
        msg0 = mailbox.BabylMessage(self._template % 0)
        msg0.add_label('foo')
        key0 = self._box.add(msg0)
        self.assertEqual(self._box.get_labels(), ['foo'])
        msg1 = mailbox.BabylMessage(self._template % 1)
        msg1.set_labels(['bar', 'answered', 'foo'])
        key1 = self._box.add(msg1)
        self.assertEqual(set(self._box.get_labels()), set(['foo', 'bar']))
        msg0.set_labels(['blah', 'filed'])
        self._box[key0] = msg0
        self.assertEqual(set(self._box.get_labels()),
                     set(['foo', 'bar', 'blah']))
        self._box.remove(key1)
        self.assertEqual(set(self._box.get_labels()), set(['blah']))


class FakeFileLikeObject:

    def __init__(self):
        self.closed = False

    def close(self):
        self.closed = True


class FakeMailBox(mailbox.Mailbox):

    def __init__(self):
        mailbox.Mailbox.__init__(self, '', lambda file: None)
        self.files = [FakeFileLikeObject() for i in range(10)]

    def get_file(self, key):
        return self.files[key]


class TestFakeMailBox(unittest.TestCase):

    def test_closing_fd(self):
        box = FakeMailBox()
        for i in range(10):
            self.assertFalse(box.files[i].closed)
        for i in range(10):
            box[i]
        for i in range(10):
            self.assertTrue(box.files[i].closed)


class TestMessage(TestBase):

    _factory = mailbox.Message      # Overridden by subclasses to reuse tests

    def setUp(self):
        self._path = support.TESTFN

    def tearDown(self):
        self._delete_recursively(self._path)

    def test_initialize_with_eMM(self):
        # Initialize based on email.message.Message instance
        eMM = email.message_from_string(_sample_message)
        msg = self._factory(eMM)
        self._post_initialize_hook(msg)
        self._check_sample(msg)

    def test_initialize_with_string(self):
        # Initialize based on string
        msg = self._factory(_sample_message)
        self._post_initialize_hook(msg)
        self._check_sample(msg)

    def test_initialize_with_file(self):
        # Initialize based on contents of file
        with open(self._path, 'w+') as f:
            f.write(_sample_message)
            f.seek(0)
            msg = self._factory(f)
            self._post_initialize_hook(msg)
            self._check_sample(msg)

    def test_initialize_with_binary_file(self):
        # Initialize based on contents of binary file
        with open(self._path, 'wb+') as f:
            f.write(_bytes_sample_message)
            f.seek(0)
            msg = self._factory(f)
            self._post_initialize_hook(msg)
            self._check_sample(msg)

    def test_initialize_with_nothing(self):
        # Initialize without arguments
        msg = self._factory()
        self._post_initialize_hook(msg)
        self.assertIsInstance(msg, email.message.Message)
        self.assertIsInstance(msg, mailbox.Message)
        self.assertIsInstance(msg, self._factory)
        self.assertEqual(msg.keys(), [])
        self.assertFalse(msg.is_multipart())
        self.assertEqual(msg.get_payload(), None)

    def test_initialize_incorrectly(self):
        # Initialize with invalid argument
        self.assertRaises(TypeError, lambda: self._factory(object()))

    def test_become_message(self):
        # Take on the state of another message
        eMM = email.message_from_string(_sample_message)
        msg = self._factory()
        msg._become_message(eMM)
        self._check_sample(msg)

    def test_explain_to(self):
        # Copy self's format-specific data to other message formats.
        # This test is superficial; better ones are in TestMessageConversion.
        msg = self._factory()
        for class_ in (mailbox.Message, mailbox.MaildirMessage,
                       mailbox.mboxMessage, mailbox.MHMessage,
                       mailbox.BabylMessage, mailbox.MMDFMessage):
            other_msg = class_()
            msg._explain_to(other_msg)
        other_msg = email.message.Message()
        self.assertRaises(TypeError, lambda: msg._explain_to(other_msg))

    def _post_initialize_hook(self, msg):
        # Overridden by subclasses to check extra things after initialization
        pass


class TestMaildirMessage(TestMessage):

    _factory = mailbox.MaildirMessage

    def _post_initialize_hook(self, msg):
        self.assertEqual(msg._subdir, 'new')
        self.assertEqual(msg._info, '')

    def test_subdir(self):
        # Use get_subdir() and set_subdir()
        msg = mailbox.MaildirMessage(_sample_message)
        self.assertEqual(msg.get_subdir(), 'new')
        msg.set_subdir('cur')
        self.assertEqual(msg.get_subdir(), 'cur')
        msg.set_subdir('new')
        self.assertEqual(msg.get_subdir(), 'new')
        self.assertRaises(ValueError, lambda: msg.set_subdir('tmp'))
        self.assertEqual(msg.get_subdir(), 'new')
        msg.set_subdir('new')
        self.assertEqual(msg.get_subdir(), 'new')
        self._check_sample(msg)

    def test_flags(self):
        # Use get_flags(), set_flags(), add_flag(), remove_flag()
        msg = mailbox.MaildirMessage(_sample_message)
        self.assertEqual(msg.get_flags(), '')
        self.assertEqual(msg.get_subdir(), 'new')
        msg.set_flags('F')
        self.assertEqual(msg.get_subdir(), 'new')
        self.assertEqual(msg.get_flags(), 'F')
        msg.set_flags('SDTP')
        self.assertEqual(msg.get_flags(), 'DPST')
        msg.add_flag('FT')
        self.assertEqual(msg.get_flags(), 'DFPST')
        msg.remove_flag('TDRP')
        self.assertEqual(msg.get_flags(), 'FS')
        self.assertEqual(msg.get_subdir(), 'new')
        self._check_sample(msg)

    def test_date(self):
        # Use get_date() and set_date()
        msg = mailbox.MaildirMessage(_sample_message)
        self.assertLess(abs(msg.get_date() - time.time()), 60)
        msg.set_date(0.0)
        self.assertEqual(msg.get_date(), 0.0)

    def test_info(self):
        # Use get_info() and set_info()
        msg = mailbox.MaildirMessage(_sample_message)
        self.assertEqual(msg.get_info(), '')
        msg.set_info('1,foo=bar')
        self.assertEqual(msg.get_info(), '1,foo=bar')
        self.assertRaises(TypeError, lambda: msg.set_info(None))
        self._check_sample(msg)

    def test_info_and_flags(self):
        # Test interaction of info and flag methods
        msg = mailbox.MaildirMessage(_sample_message)
        self.assertEqual(msg.get_info(), '')
        msg.set_flags('SF')
        self.assertEqual(msg.get_flags(), 'FS')
        self.assertEqual(msg.get_info(), '2,FS')
        msg.set_info('1,')
        self.assertEqual(msg.get_flags(), '')
        self.assertEqual(msg.get_info(), '1,')
        msg.remove_flag('RPT')
        self.assertEqual(msg.get_flags(), '')
        self.assertEqual(msg.get_info(), '1,')
        msg.add_flag('D')
        self.assertEqual(msg.get_flags(), 'D')
        self.assertEqual(msg.get_info(), '2,D')
        self._check_sample(msg)


class _TestMboxMMDFMessage(TestMessage):

    _factory = mailbox._mboxMMDFMessage

    def _post_initialize_hook(self, msg):
        self._check_from(msg)

    def test_initialize_with_unixfrom(self):
        # Initialize with a message that already has a _unixfrom attribute
        msg = mailbox.Message(_sample_message)
        msg.set_unixfrom('From foo@bar blah')
        msg = mailbox.mboxMessage(msg)
        self.assertEqual(msg.get_from(), 'foo@bar blah', msg.get_from())

    def test_from(self):
        # Get and set "From " line
        msg = mailbox.mboxMessage(_sample_message)
        self._check_from(msg)
        msg.set_from('foo bar')
        self.assertEqual(msg.get_from(), 'foo bar')
        msg.set_from('foo@bar', True)
        self._check_from(msg, 'foo@bar')
        msg.set_from('blah@temp', time.localtime())
        self._check_from(msg, 'blah@temp')

    def test_flags(self):
        # Use get_flags(), set_flags(), add_flag(), remove_flag()
        msg = mailbox.mboxMessage(_sample_message)
        self.assertEqual(msg.get_flags(), '')
        msg.set_flags('F')
        self.assertEqual(msg.get_flags(), 'F')
        msg.set_flags('XODR')
        self.assertEqual(msg.get_flags(), 'RODX')
        msg.add_flag('FA')
        self.assertEqual(msg.get_flags(), 'RODFAX')
        msg.remove_flag('FDXA')
        self.assertEqual(msg.get_flags(), 'RO')
        self._check_sample(msg)

    def _check_from(self, msg, sender=None):
        # Check contents of "From " line
        if sender is None:
            sender = "MAILER-DAEMON"
        self.assertTrue(re.match(sender + r" \w{3} \w{3} [\d ]\d [\d ]\d:\d{2}:"
                              r"\d{2} \d{4}", msg.get_from()) is not None)


class TestMboxMessage(_TestMboxMMDFMessage):

    _factory = mailbox.mboxMessage


class TestMHMessage(TestMessage):

    _factory = mailbox.MHMessage

    def _post_initialize_hook(self, msg):
        self.assertEqual(msg._sequences, [])

    def test_sequences(self):
        # Get, set, join, and leave sequences
        msg = mailbox.MHMessage(_sample_message)
        self.assertEqual(msg.get_sequences(), [])
        msg.set_sequences(['foobar'])
        self.assertEqual(msg.get_sequences(), ['foobar'])
        msg.set_sequences([])
        self.assertEqual(msg.get_sequences(), [])
        msg.add_sequence('unseen')
        self.assertEqual(msg.get_sequences(), ['unseen'])
        msg.add_sequence('flagged')
        self.assertEqual(msg.get_sequences(), ['unseen', 'flagged'])
        msg.add_sequence('flagged')
        self.assertEqual(msg.get_sequences(), ['unseen', 'flagged'])
        msg.remove_sequence('unseen')
        self.assertEqual(msg.get_sequences(), ['flagged'])
        msg.add_sequence('foobar')
        self.assertEqual(msg.get_sequences(), ['flagged', 'foobar'])
        msg.remove_sequence('replied')
        self.assertEqual(msg.get_sequences(), ['flagged', 'foobar'])
        msg.set_sequences(['foobar', 'replied'])
        self.assertEqual(msg.get_sequences(), ['foobar', 'replied'])


class TestBabylMessage(TestMessage):

    _factory = mailbox.BabylMessage

    def _post_initialize_hook(self, msg):
        self.assertEqual(msg._labels, [])

    def test_labels(self):
        # Get, set, join, and leave labels
        msg = mailbox.BabylMessage(_sample_message)
        self.assertEqual(msg.get_labels(), [])
        msg.set_labels(['foobar'])
        self.assertEqual(msg.get_labels(), ['foobar'])
        msg.set_labels([])
        self.assertEqual(msg.get_labels(), [])
        msg.add_label('filed')
        self.assertEqual(msg.get_labels(), ['filed'])
        msg.add_label('resent')
        self.assertEqual(msg.get_labels(), ['filed', 'resent'])
        msg.add_label('resent')
        self.assertEqual(msg.get_labels(), ['filed', 'resent'])
        msg.remove_label('filed')
        self.assertEqual(msg.get_labels(), ['resent'])
        msg.add_label('foobar')
        self.assertEqual(msg.get_labels(), ['resent', 'foobar'])
        msg.remove_label('unseen')
        self.assertEqual(msg.get_labels(), ['resent', 'foobar'])
        msg.set_labels(['foobar', 'answered'])
        self.assertEqual(msg.get_labels(), ['foobar', 'answered'])

    def test_visible(self):
        # Get, set, and update visible headers
        msg = mailbox.BabylMessage(_sample_message)
        visible = msg.get_visible()
        self.assertEqual(visible.keys(), [])
        self.assertIs(visible.get_payload(), None)
        visible['User-Agent'] = 'FooBar 1.0'
        visible['X-Whatever'] = 'Blah'
        self.assertEqual(msg.get_visible().keys(), [])
        msg.set_visible(visible)
        visible = msg.get_visible()
        self.assertTrue(visible.keys() == ['User-Agent', 'X-Whatever'])
        self.assertTrue(visible['User-Agent'] == 'FooBar 1.0')
        self.assertEqual(visible['X-Whatever'], 'Blah')
        self.assertIs(visible.get_payload(), None)
        msg.update_visible()
        self.assertEqual(visible.keys(), ['User-Agent', 'X-Whatever'])
        self.assertIs(visible.get_payload(), None)
        visible = msg.get_visible()
        self.assertEqual(visible.keys(), ['User-Agent', 'Date', 'From', 'To',
                                          'Subject'])
        for header in ('User-Agent', 'Date', 'From', 'To', 'Subject'):
            self.assertEqual(visible[header], msg[header])


class TestMMDFMessage(_TestMboxMMDFMessage):

    _factory = mailbox.MMDFMessage


class TestMessageConversion(TestBase):

    def test_plain_to_x(self):
        # Convert Message to all formats
        for class_ in (mailbox.Message, mailbox.MaildirMessage,
                       mailbox.mboxMessage, mailbox.MHMessage,
                       mailbox.BabylMessage, mailbox.MMDFMessage):
            msg_plain = mailbox.Message(_sample_message)
            msg = class_(msg_plain)
            self._check_sample(msg)

    def test_x_to_plain(self):
        # Convert all formats to Message
        for class_ in (mailbox.Message, mailbox.MaildirMessage,
                       mailbox.mboxMessage, mailbox.MHMessage,
                       mailbox.BabylMessage, mailbox.MMDFMessage):
            msg = class_(_sample_message)
            msg_plain = mailbox.Message(msg)
            self._check_sample(msg_plain)

    def test_x_from_bytes(self):
        # Convert all formats to Message
        for class_ in (mailbox.Message, mailbox.MaildirMessage,
                       mailbox.mboxMessage, mailbox.MHMessage,
                       mailbox.BabylMessage, mailbox.MMDFMessage):
            msg = class_(_bytes_sample_message)
            self._check_sample(msg)

    def test_x_to_invalid(self):
        # Convert all formats to an invalid format
        for class_ in (mailbox.Message, mailbox.MaildirMessage,
                       mailbox.mboxMessage, mailbox.MHMessage,
                       mailbox.BabylMessage, mailbox.MMDFMessage):
            self.assertRaises(TypeError, lambda: class_(False))

    def test_maildir_to_maildir(self):
        # Convert MaildirMessage to MaildirMessage
        msg_maildir = mailbox.MaildirMessage(_sample_message)
        msg_maildir.set_flags('DFPRST')
        msg_maildir.set_subdir('cur')
        date = msg_maildir.get_date()
        msg = mailbox.MaildirMessage(msg_maildir)
        self._check_sample(msg)
        self.assertEqual(msg.get_flags(), 'DFPRST')
        self.assertEqual(msg.get_subdir(), 'cur')
        self.assertEqual(msg.get_date(), date)

    def test_maildir_to_mboxmmdf(self):
        # Convert MaildirMessage to mboxmessage and MMDFMessage
        pairs = (('D', ''), ('F', 'F'), ('P', ''), ('R', 'A'), ('S', 'R'),
                 ('T', 'D'), ('DFPRST', 'RDFA'))
        for class_ in (mailbox.mboxMessage, mailbox.MMDFMessage):
            msg_maildir = mailbox.MaildirMessage(_sample_message)
            msg_maildir.set_date(0.0)
            for setting, result in pairs:
                msg_maildir.set_flags(setting)
                msg = class_(msg_maildir)
                self.assertEqual(msg.get_flags(), result)
                self.assertEqual(msg.get_from(), 'MAILER-DAEMON %s' %
                             time.asctime(time.gmtime(0.0)))
            msg_maildir.set_subdir('cur')
            self.assertEqual(class_(msg_maildir).get_flags(), 'RODFA')

    def test_maildir_to_mh(self):
        # Convert MaildirMessage to MHMessage
        msg_maildir = mailbox.MaildirMessage(_sample_message)
        pairs = (('D', ['unseen']), ('F', ['unseen', 'flagged']),
                 ('P', ['unseen']), ('R', ['unseen', 'replied']), ('S', []),
                 ('T', ['unseen']), ('DFPRST', ['replied', 'flagged']))
        for setting, result in pairs:
            msg_maildir.set_flags(setting)
            self.assertEqual(mailbox.MHMessage(msg_maildir).get_sequences(),
                             result)

    def test_maildir_to_babyl(self):
        # Convert MaildirMessage to Babyl
        msg_maildir = mailbox.MaildirMessage(_sample_message)
        pairs = (('D', ['unseen']), ('F', ['unseen']),
                 ('P', ['unseen', 'forwarded']), ('R', ['unseen', 'answered']),
                 ('S', []), ('T', ['unseen', 'deleted']),
                 ('DFPRST', ['deleted', 'answered', 'forwarded']))
        for setting, result in pairs:
            msg_maildir.set_flags(setting)
            self.assertEqual(mailbox.BabylMessage(msg_maildir).get_labels(),
                             result)

    def test_mboxmmdf_to_maildir(self):
        # Convert mboxMessage and MMDFMessage to MaildirMessage
        for class_ in (mailbox.mboxMessage, mailbox.MMDFMessage):
            msg_mboxMMDF = class_(_sample_message)
            msg_mboxMMDF.set_from('foo@bar', time.gmtime(0.0))
            pairs = (('R', 'S'), ('O', ''), ('D', 'T'), ('F', 'F'), ('A', 'R'),
                     ('RODFA', 'FRST'))
            for setting, result in pairs:
                msg_mboxMMDF.set_flags(setting)
                msg = mailbox.MaildirMessage(msg_mboxMMDF)
                self.assertEqual(msg.get_flags(), result)
                self.assertEqual(msg.get_date(), 0.0)
            msg_mboxMMDF.set_flags('O')
            self.assertEqual(mailbox.MaildirMessage(msg_mboxMMDF).get_subdir(),
                             'cur')

    def test_mboxmmdf_to_mboxmmdf(self):
        # Convert mboxMessage and MMDFMessage to mboxMessage and MMDFMessage
        for class_ in (mailbox.mboxMessage, mailbox.MMDFMessage):
            msg_mboxMMDF = class_(_sample_message)
            msg_mboxMMDF.set_flags('RODFA')
            msg_mboxMMDF.set_from('foo@bar')
            for class2_ in (mailbox.mboxMessage, mailbox.MMDFMessage):
                msg2 = class2_(msg_mboxMMDF)
                self.assertEqual(msg2.get_flags(), 'RODFA')
                self.assertEqual(msg2.get_from(), 'foo@bar')

    def test_mboxmmdf_to_mh(self):
        # Convert mboxMessage and MMDFMessage to MHMessage
        for class_ in (mailbox.mboxMessage, mailbox.MMDFMessage):
            msg_mboxMMDF = class_(_sample_message)
            pairs = (('R', []), ('O', ['unseen']), ('D', ['unseen']),
                     ('F', ['unseen', 'flagged']),
                     ('A', ['unseen', 'replied']),
                     ('RODFA', ['replied', 'flagged']))
            for setting, result in pairs:
                msg_mboxMMDF.set_flags(setting)
                self.assertEqual(mailbox.MHMessage(msg_mboxMMDF).get_sequences(),
                                 result)

    def test_mboxmmdf_to_babyl(self):
        # Convert mboxMessage and MMDFMessage to BabylMessage
        for class_ in (mailbox.mboxMessage, mailbox.MMDFMessage):
            msg = class_(_sample_message)
            pairs = (('R', []), ('O', ['unseen']),
                     ('D', ['unseen', 'deleted']), ('F', ['unseen']),
                     ('A', ['unseen', 'answered']),
                     ('RODFA', ['deleted', 'answered']))
            for setting, result in pairs:
                msg.set_flags(setting)
                self.assertEqual(mailbox.BabylMessage(msg).get_labels(), result)

    def test_mh_to_maildir(self):
        # Convert MHMessage to MaildirMessage
        pairs = (('unseen', ''), ('replied', 'RS'), ('flagged', 'FS'))
        for setting, result in pairs:
            msg = mailbox.MHMessage(_sample_message)
            msg.add_sequence(setting)
            self.assertEqual(mailbox.MaildirMessage(msg).get_flags(), result)
            self.assertEqual(mailbox.MaildirMessage(msg).get_subdir(), 'cur')
        msg = mailbox.MHMessage(_sample_message)
        msg.add_sequence('unseen')
        msg.add_sequence('replied')
        msg.add_sequence('flagged')
        self.assertEqual(mailbox.MaildirMessage(msg).get_flags(), 'FR')
        self.assertEqual(mailbox.MaildirMessage(msg).get_subdir(), 'cur')

    def test_mh_to_mboxmmdf(self):
        # Convert MHMessage to mboxMessage and MMDFMessage
        pairs = (('unseen', 'O'), ('replied', 'ROA'), ('flagged', 'ROF'))
        for setting, result in pairs:
            msg = mailbox.MHMessage(_sample_message)
            msg.add_sequence(setting)
            for class_ in (mailbox.mboxMessage, mailbox.MMDFMessage):
                self.assertEqual(class_(msg).get_flags(), result)
        msg = mailbox.MHMessage(_sample_message)
        msg.add_sequence('unseen')
        msg.add_sequence('replied')
        msg.add_sequence('flagged')
        for class_ in (mailbox.mboxMessage, mailbox.MMDFMessage):
            self.assertEqual(class_(msg).get_flags(), 'OFA')

    def test_mh_to_mh(self):
        # Convert MHMessage to MHMessage
        msg = mailbox.MHMessage(_sample_message)
        msg.add_sequence('unseen')
        msg.add_sequence('replied')
        msg.add_sequence('flagged')
        self.assertEqual(mailbox.MHMessage(msg).get_sequences(),
                         ['unseen', 'replied', 'flagged'])

    def test_mh_to_babyl(self):
        # Convert MHMessage to BabylMessage
        pairs = (('unseen', ['unseen']), ('replied', ['answered']),
                 ('flagged', []))
        for setting, result in pairs:
            msg = mailbox.MHMessage(_sample_message)
            msg.add_sequence(setting)
            self.assertEqual(mailbox.BabylMessage(msg).get_labels(), result)
        msg = mailbox.MHMessage(_sample_message)
        msg.add_sequence('unseen')
        msg.add_sequence('replied')
        msg.add_sequence('flagged')
        self.assertEqual(mailbox.BabylMessage(msg).get_labels(),
                         ['unseen', 'answered'])

    def test_babyl_to_maildir(self):
        # Convert BabylMessage to MaildirMessage
        pairs = (('unseen', ''), ('deleted', 'ST'), ('filed', 'S'),
                 ('answered', 'RS'), ('forwarded', 'PS'), ('edited', 'S'),
                 ('resent', 'PS'))
        for setting, result in pairs:
            msg = mailbox.BabylMessage(_sample_message)
            msg.add_label(setting)
            self.assertEqual(mailbox.MaildirMessage(msg).get_flags(), result)
            self.assertEqual(mailbox.MaildirMessage(msg).get_subdir(), 'cur')
        msg = mailbox.BabylMessage(_sample_message)
        for label in ('unseen', 'deleted', 'filed', 'answered', 'forwarded',
                      'edited', 'resent'):
            msg.add_label(label)
        self.assertEqual(mailbox.MaildirMessage(msg).get_flags(), 'PRT')
        self.assertEqual(mailbox.MaildirMessage(msg).get_subdir(), 'cur')

    def test_babyl_to_mboxmmdf(self):
        # Convert BabylMessage to mboxMessage and MMDFMessage
        pairs = (('unseen', 'O'), ('deleted', 'ROD'), ('filed', 'RO'),
                 ('answered', 'ROA'), ('forwarded', 'RO'), ('edited', 'RO'),
                 ('resent', 'RO'))
        for setting, result in pairs:
            for class_ in (mailbox.mboxMessage, mailbox.MMDFMessage):
                msg = mailbox.BabylMessage(_sample_message)
                msg.add_label(setting)
                self.assertEqual(class_(msg).get_flags(), result)
        msg = mailbox.BabylMessage(_sample_message)
        for label in ('unseen', 'deleted', 'filed', 'answered', 'forwarded',
                      'edited', 'resent'):
            msg.add_label(label)
        for class_ in (mailbox.mboxMessage, mailbox.MMDFMessage):
            self.assertEqual(class_(msg).get_flags(), 'ODA')

    def test_babyl_to_mh(self):
        # Convert BabylMessage to MHMessage
        pairs = (('unseen', ['unseen']), ('deleted', []), ('filed', []),
                 ('answered', ['replied']), ('forwarded', []), ('edited', []),
                 ('resent', []))
        for setting, result in pairs:
            msg = mailbox.BabylMessage(_sample_message)
            msg.add_label(setting)
            self.assertEqual(mailbox.MHMessage(msg).get_sequences(), result)
        msg = mailbox.BabylMessage(_sample_message)
        for label in ('unseen', 'deleted', 'filed', 'answered', 'forwarded',
                      'edited', 'resent'):
            msg.add_label(label)
        self.assertEqual(mailbox.MHMessage(msg).get_sequences(),
                         ['unseen', 'replied'])

    def test_babyl_to_babyl(self):
        # Convert BabylMessage to BabylMessage
        msg = mailbox.BabylMessage(_sample_message)
        msg.update_visible()
        for label in ('unseen', 'deleted', 'filed', 'answered', 'forwarded',
                      'edited', 'resent'):
            msg.add_label(label)
        msg2 = mailbox.BabylMessage(msg)
        self.assertEqual(msg2.get_labels(), ['unseen', 'deleted', 'filed',
                                             'answered', 'forwarded', 'edited',
                                             'resent'])
        self.assertEqual(msg.get_visible().keys(), msg2.get_visible().keys())
        for key in msg.get_visible().keys():
            self.assertEqual(msg.get_visible()[key], msg2.get_visible()[key])


class TestProxyFileBase(TestBase):

    def _test_read(self, proxy):
        # Read by byte
        proxy.seek(0)
        self.assertEqual(proxy.read(), b'bar')
        proxy.seek(1)
        self.assertEqual(proxy.read(), b'ar')
        proxy.seek(0)
        self.assertEqual(proxy.read(2), b'ba')
        proxy.seek(1)
        self.assertEqual(proxy.read(-1), b'ar')
        proxy.seek(2)
        self.assertEqual(proxy.read(1000), b'r')

    def _test_readline(self, proxy):
        # Read by line
        linesep = os.linesep.encode()
        proxy.seek(0)
        self.assertEqual(proxy.readline(), b'foo' + linesep)
        self.assertEqual(proxy.readline(), b'bar' + linesep)
        self.assertEqual(proxy.readline(), b'fred' + linesep)
        self.assertEqual(proxy.readline(), b'bob')
        proxy.seek(2)
        self.assertEqual(proxy.readline(), b'o' + linesep)
        proxy.seek(6 + 2 * len(os.linesep))
        self.assertEqual(proxy.readline(), b'fred' + linesep)
        proxy.seek(6 + 2 * len(os.linesep))
        self.assertEqual(proxy.readline(2), b'fr')
        self.assertEqual(proxy.readline(-10), b'ed' + linesep)

    def _test_readlines(self, proxy):
        # Read multiple lines
        linesep = os.linesep.encode()
        proxy.seek(0)
        self.assertEqual(proxy.readlines(), [b'foo' + linesep,
                                           b'bar' + linesep,
                                           b'fred' + linesep, b'bob'])
        proxy.seek(0)
        self.assertEqual(proxy.readlines(2), [b'foo' + linesep])
        proxy.seek(3 + len(linesep))
        self.assertEqual(proxy.readlines(4 + len(linesep)),
                     [b'bar' + linesep, b'fred' + linesep])
        proxy.seek(3)
        self.assertEqual(proxy.readlines(1000), [linesep, b'bar' + linesep,
                                               b'fred' + linesep, b'bob'])

    def _test_iteration(self, proxy):
        # Iterate by line
        linesep = os.linesep.encode()
        proxy.seek(0)
        iterator = iter(proxy)
        self.assertEqual(next(iterator), b'foo' + linesep)
        self.assertEqual(next(iterator), b'bar' + linesep)
        self.assertEqual(next(iterator), b'fred' + linesep)
        self.assertEqual(next(iterator), b'bob')
        self.assertRaises(StopIteration, next, iterator)

    def _test_seek_and_tell(self, proxy):
        # Seek and use tell to check position
        linesep = os.linesep.encode()
        proxy.seek(3)
        self.assertEqual(proxy.tell(), 3)
        self.assertEqual(proxy.read(len(linesep)), linesep)
        proxy.seek(2, 1)
        self.assertEqual(proxy.read(1 + len(linesep)), b'r' + linesep)
        proxy.seek(-3 - len(linesep), 2)
        self.assertEqual(proxy.read(3), b'bar')
        proxy.seek(2, 0)
        self.assertEqual(proxy.read(), b'o' + linesep + b'bar' + linesep)
        proxy.seek(100)
        self.assertFalse(proxy.read())

    def _test_close(self, proxy):
        # Close a file
        self.assertFalse(proxy.closed)
        proxy.close()
        self.assertTrue(proxy.closed)
        # Issue 11700 subsequent closes should be a no-op.
        proxy.close()
        self.assertTrue(proxy.closed)


class TestProxyFile(TestProxyFileBase):

    def setUp(self):
        self._path = support.TESTFN
        self._file = open(self._path, 'wb+')

    def tearDown(self):
        self._file.close()
        self._delete_recursively(self._path)

    def test_initialize(self):
        # Initialize and check position
        self._file.write(b'foo')
        pos = self._file.tell()
        proxy0 = mailbox._ProxyFile(self._file)
        self.assertEqual(proxy0.tell(), pos)
        self.assertEqual(self._file.tell(), pos)
        proxy1 = mailbox._ProxyFile(self._file, 0)
        self.assertEqual(proxy1.tell(), 0)
        self.assertEqual(self._file.tell(), pos)

    def test_read(self):
        self._file.write(b'bar')
        self._test_read(mailbox._ProxyFile(self._file))

    def test_readline(self):
        self._file.write(bytes('foo%sbar%sfred%sbob' % (os.linesep, os.linesep,
                                                  os.linesep), 'ascii'))
        self._test_readline(mailbox._ProxyFile(self._file))

    def test_readlines(self):
        self._file.write(bytes('foo%sbar%sfred%sbob' % (os.linesep, os.linesep,
                                                  os.linesep), 'ascii'))
        self._test_readlines(mailbox._ProxyFile(self._file))

    def test_iteration(self):
        self._file.write(bytes('foo%sbar%sfred%sbob' % (os.linesep, os.linesep,
                                                  os.linesep), 'ascii'))
        self._test_iteration(mailbox._ProxyFile(self._file))

    def test_seek_and_tell(self):
        self._file.write(bytes('foo%sbar%s' % (os.linesep, os.linesep), 'ascii'))
        self._test_seek_and_tell(mailbox._ProxyFile(self._file))

    def test_close(self):
        self._file.write(bytes('foo%sbar%s' % (os.linesep, os.linesep), 'ascii'))
        self._test_close(mailbox._ProxyFile(self._file))


class TestPartialFile(TestProxyFileBase):

    def setUp(self):
        self._path = support.TESTFN
        self._file = open(self._path, 'wb+')

    def tearDown(self):
        self._file.close()
        self._delete_recursively(self._path)

    def test_initialize(self):
        # Initialize and check position
        self._file.write(bytes('foo' + os.linesep + 'bar', 'ascii'))
        pos = self._file.tell()
        proxy = mailbox._PartialFile(self._file, 2, 5)
        self.assertEqual(proxy.tell(), 0)
        self.assertEqual(self._file.tell(), pos)

    def test_read(self):
        self._file.write(bytes('***bar***', 'ascii'))
        self._test_read(mailbox._PartialFile(self._file, 3, 6))

    def test_readline(self):
        self._file.write(bytes('!!!!!foo%sbar%sfred%sbob!!!!!' %
                         (os.linesep, os.linesep, os.linesep), 'ascii'))
        self._test_readline(mailbox._PartialFile(self._file, 5,
                                                 18 + 3 * len(os.linesep)))

    def test_readlines(self):
        self._file.write(bytes('foo%sbar%sfred%sbob?????' %
                         (os.linesep, os.linesep, os.linesep), 'ascii'))
        self._test_readlines(mailbox._PartialFile(self._file, 0,
                                                  13 + 3 * len(os.linesep)))

    def test_iteration(self):
        self._file.write(bytes('____foo%sbar%sfred%sbob####' %
                         (os.linesep, os.linesep, os.linesep), 'ascii'))
        self._test_iteration(mailbox._PartialFile(self._file, 4,
                                                  17 + 3 * len(os.linesep)))

    def test_seek_and_tell(self):
        self._file.write(bytes('(((foo%sbar%s$$$' % (os.linesep, os.linesep), 'ascii'))
        self._test_seek_and_tell(mailbox._PartialFile(self._file, 3,
                                                      9 + 2 * len(os.linesep)))

    def test_close(self):
        self._file.write(bytes('&foo%sbar%s^' % (os.linesep, os.linesep), 'ascii'))
        self._test_close(mailbox._PartialFile(self._file, 1,
                                              6 + 3 * len(os.linesep)))


## Start: tests from the original module (for backward compatibility).

FROM_ = "From some.body@dummy.domain  Sat Jul 24 13:43:35 2004\n"
DUMMY_MESSAGE = """\
From: some.body@dummy.domain
To: me@my.domain
Subject: Simple Test

This is a dummy message.
"""

class MaildirTestCase(unittest.TestCase):

    def setUp(self):
        # create a new maildir mailbox to work with:
        self._dir = support.TESTFN
        os.mkdir(self._dir)
        os.mkdir(os.path.join(self._dir, "cur"))
        os.mkdir(os.path.join(self._dir, "tmp"))
        os.mkdir(os.path.join(self._dir, "new"))
        self._counter = 1
        self._msgfiles = []

    def tearDown(self):
        list(map(os.unlink, self._msgfiles))
        os.rmdir(os.path.join(self._dir, "cur"))
        os.rmdir(os.path.join(self._dir, "tmp"))
        os.rmdir(os.path.join(self._dir, "new"))
        os.rmdir(self._dir)

    def createMessage(self, dir, mbox=False):
        t = int(time.time() % 1000000)
        pid = self._counter
        self._counter += 1
        filename = ".".join((str(t), str(pid), "myhostname", "mydomain"))
        tmpname = os.path.join(self._dir, "tmp", filename)
        newname = os.path.join(self._dir, dir, filename)
        with open(tmpname, "w") as fp:
            self._msgfiles.append(tmpname)
            if mbox:
                fp.write(FROM_)
            fp.write(DUMMY_MESSAGE)
        if hasattr(os, "link"):
            os.link(tmpname, newname)
        else:
            with open(newname, "w") as fp:
                fp.write(DUMMY_MESSAGE)
        self._msgfiles.append(newname)
        return tmpname

    def test_empty_maildir(self):
        """Test an empty maildir mailbox"""
        # Test for regression on bug #117490:
        # Make sure the boxes attribute actually gets set.
        self.mbox = mailbox.Maildir(support.TESTFN)
        #self.assertTrue(hasattr(self.mbox, "boxes"))
        #self.assertEqual(len(self.mbox.boxes), 0)
        self.assertIs(self.mbox.next(), None)
        self.assertIs(self.mbox.next(), None)

    def test_nonempty_maildir_cur(self):
        self.createMessage("cur")
        self.mbox = mailbox.Maildir(support.TESTFN)
        #self.assertEqual(len(self.mbox.boxes), 1)
        self.assertIsNot(self.mbox.next(), None)
        self.assertIs(self.mbox.next(), None)
        self.assertIs(self.mbox.next(), None)

    def test_nonempty_maildir_new(self):
        self.createMessage("new")
        self.mbox = mailbox.Maildir(support.TESTFN)
        #self.assertEqual(len(self.mbox.boxes), 1)
        self.assertIsNot(self.mbox.next(), None)
        self.assertIs(self.mbox.next(), None)
        self.assertIs(self.mbox.next(), None)

    def test_nonempty_maildir_both(self):
        self.createMessage("cur")
        self.createMessage("new")
        self.mbox = mailbox.Maildir(support.TESTFN)
        #self.assertEqual(len(self.mbox.boxes), 2)
        self.assertIsNot(self.mbox.next(), None)
        self.assertIsNot(self.mbox.next(), None)
        self.assertIs(self.mbox.next(), None)
        self.assertIs(self.mbox.next(), None)

## End: tests from the original module (for backward compatibility).


_sample_message = """\
Return-Path: <gkj@gregorykjohnson.com>
X-Original-To: gkj+person@localhost
Delivered-To: gkj+person@localhost
Received: from localhost (localhost [127.0.0.1])
        by andy.gregorykjohnson.com (Postfix) with ESMTP id 356ED9DD17
        for <gkj+person@localhost>; Wed, 13 Jul 2005 17:23:16 -0400 (EDT)
Delivered-To: gkj@sundance.gregorykjohnson.com
Received: from localhost [127.0.0.1]
        by localhost with POP3 (fetchmail-6.2.5)
        for gkj+person@localhost (single-drop); Wed, 13 Jul 2005 17:23:16 -0400 (EDT)
Received: from andy.gregorykjohnson.com (andy.gregorykjohnson.com [64.32.235.228])
        by sundance.gregorykjohnson.com (Postfix) with ESMTP id 5B056316746
        for <gkj@gregorykjohnson.com>; Wed, 13 Jul 2005 17:23:11 -0400 (EDT)
Received: by andy.gregorykjohnson.com (Postfix, from userid 1000)
        id 490CD9DD17; Wed, 13 Jul 2005 17:23:11 -0400 (EDT)
Date: Wed, 13 Jul 2005 17:23:11 -0400
From: "Gregory K. Johnson" <gkj@gregorykjohnson.com>
To: gkj@gregorykjohnson.com
Subject: Sample message
Message-ID: <20050713212311.GC4701@andy.gregorykjohnson.com>
Mime-Version: 1.0
Content-Type: multipart/mixed; boundary="NMuMz9nt05w80d4+"
Content-Disposition: inline
User-Agent: Mutt/1.5.9i


--NMuMz9nt05w80d4+
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline

This is a sample message.

--
Gregory K. Johnson

--NMuMz9nt05w80d4+
Content-Type: application/octet-stream
Content-Disposition: attachment; filename="text.gz"
Content-Transfer-Encoding: base64

H4sICM2D1UIAA3RleHQAC8nILFYAokSFktSKEoW0zJxUPa7wzJIMhZLyfIWczLzUYj0uAHTs
3FYlAAAA

--NMuMz9nt05w80d4+--
"""

_bytes_sample_message = _sample_message.encode('ascii')

_sample_headers = {
    "Return-Path":"<gkj@gregorykjohnson.com>",
    "X-Original-To":"gkj+person@localhost",
    "Delivered-To":"gkj+person@localhost",
    "Received":"""from localhost (localhost [127.0.0.1])
        by andy.gregorykjohnson.com (Postfix) with ESMTP id 356ED9DD17
        for <gkj+person@localhost>; Wed, 13 Jul 2005 17:23:16 -0400 (EDT)""",
    "Delivered-To":"gkj@sundance.gregorykjohnson.com",
    "Received":"""from localhost [127.0.0.1]
        by localhost with POP3 (fetchmail-6.2.5)
        for gkj+person@localhost (single-drop); Wed, 13 Jul 2005 17:23:16 -0400 (EDT)""",
    "Received":"""from andy.gregorykjohnson.com (andy.gregorykjohnson.com [64.32.235.228])
        by sundance.gregorykjohnson.com (Postfix) with ESMTP id 5B056316746
        for <gkj@gregorykjohnson.com>; Wed, 13 Jul 2005 17:23:11 -0400 (EDT)""",
    "Received":"""by andy.gregorykjohnson.com (Postfix, from userid 1000)
        id 490CD9DD17; Wed, 13 Jul 2005 17:23:11 -0400 (EDT)""",
    "Date":"Wed, 13 Jul 2005 17:23:11 -0400",
    "From":""""Gregory K. Johnson" <gkj@gregorykjohnson.com>""",
    "To":"gkj@gregorykjohnson.com",
    "Subject":"Sample message",
    "Mime-Version":"1.0",
    "Content-Type":"""multipart/mixed; boundary="NMuMz9nt05w80d4+\"""",
    "Content-Disposition":"inline",
    "User-Agent": "Mutt/1.5.9i" }

_sample_payloads = ("""This is a sample message.

--
Gregory K. Johnson
""",
"""H4sICM2D1UIAA3RleHQAC8nILFYAokSFktSKEoW0zJxUPa7wzJIMhZLyfIWczLzUYj0uAHTs
3FYlAAAA
""")


def test_main():
    tests = (TestMailboxSuperclass, TestMaildir, TestMbox, TestMMDF, TestMH,
             TestBabyl, TestMessage, TestMaildirMessage, TestMboxMessage,
             TestMHMessage, TestBabylMessage, TestMMDFMessage,
             TestMessageConversion, TestProxyFile, TestPartialFile,
             MaildirTestCase, TestFakeMailBox)
    support.run_unittest(*tests)
    support.reap_children()


if __name__ == '__main__':
    test_main()