import unittest from test import support, mock_socket import socket import io import smtpd import asyncore class DummyServer(smtpd.SMTPServer): def __init__(self, localaddr, remoteaddr, decode_data=True): smtpd.SMTPServer.__init__(self, localaddr, remoteaddr, decode_data=decode_data) self.messages = [] if decode_data: self.return_status = 'return status' else: self.return_status = b'return status' def process_message(self, peer, mailfrom, rcpttos, data): self.messages.append((peer, mailfrom, rcpttos, data)) if data == self.return_status: return '250 Okish' class DummyDispatcherBroken(Exception): pass class BrokenDummyServer(DummyServer): def listen(self, num): raise DummyDispatcherBroken() class SMTPDServerTest(unittest.TestCase): def setUp(self): smtpd.socket = asyncore.socket = mock_socket def test_process_message_unimplemented(self): server = smtpd.SMTPServer((support.HOST, 0), ('b', 0), decode_data=True) conn, addr = server.accept() channel = smtpd.SMTPChannel(server, conn, addr, decode_data=True) def write_line(line): channel.socket.queue_recv(line) channel.handle_read() write_line(b'HELO example') write_line(b'MAIL From:eggs@example') write_line(b'RCPT To:spam@example') write_line(b'DATA') self.assertRaises(NotImplementedError, write_line, b'spam\r\n.\r\n') def test_decode_data_default_warns(self): with self.assertWarns(DeprecationWarning): smtpd.SMTPServer((support.HOST, 0), ('b', 0)) def tearDown(self): asyncore.close_all() asyncore.socket = smtpd.socket = socket class TestFamilyDetection(unittest.TestCase): def setUp(self): smtpd.socket = asyncore.socket = mock_socket def tearDown(self): asyncore.close_all() asyncore.socket = smtpd.socket = socket @unittest.skipUnless(support.IPV6_ENABLED, "IPv6 not enabled") def test_socket_uses_IPv6(self): server = smtpd.SMTPServer((support.HOSTv6, 0), (support.HOST, 0), decode_data=False) self.assertEqual(server.socket.family, socket.AF_INET6) def test_socket_uses_IPv4(self): server = smtpd.SMTPServer((support.HOST, 0), (support.HOSTv6, 0), decode_data=False) self.assertEqual(server.socket.family, socket.AF_INET) class SMTPDChannelTest(unittest.TestCase): def setUp(self): smtpd.socket = asyncore.socket = mock_socket self.old_debugstream = smtpd.DEBUGSTREAM self.debug = smtpd.DEBUGSTREAM = io.StringIO() self.server = DummyServer((support.HOST, 0), ('b', 0)) conn, addr = self.server.accept() self.channel = smtpd.SMTPChannel(self.server, conn, addr, decode_data=True) def tearDown(self): asyncore.close_all() asyncore.socket = smtpd.socket = socket smtpd.DEBUGSTREAM = self.old_debugstream def write_line(self, line): self.channel.socket.queue_recv(line) self.channel.handle_read() def test_broken_connect(self): self.assertRaises( DummyDispatcherBroken, BrokenDummyServer, (support.HOST, 0), ('b', 0)) def test_server_accept(self): self.server.handle_accept() def test_missing_data(self): self.write_line(b'') self.assertEqual(self.channel.socket.last, b'500 Error: bad syntax\r\n') def test_EHLO(self): self.write_line(b'EHLO example') self.assertEqual(self.channel.socket.last, b'250 HELP\r\n') def test_EHLO_bad_syntax(self): self.write_line(b'EHLO') self.assertEqual(self.channel.socket.last, b'501 Syntax: EHLO hostname\r\n') def test_EHLO_duplicate(self): self.write_line(b'EHLO example') self.write_line(b'EHLO example') self.assertEqual(self.channel.socket.last, b'503 Duplicate HELO/EHLO\r\n') def test_EHLO_HELO_duplicate(self): self.write_line(b'EHLO example') self.write_line(b'HELO example') self.assertEqual(self.channel.socket.last, b'503 Duplicate HELO/EHLO\r\n') def test_HELO(self): name = smtpd.socket.getfqdn() self.write_line(b'HELO example') self.assertEqual(self.channel.socket.last, '250 {}\r\n'.format(name).encode('ascii')) def test_HELO_EHLO_duplicate(self): self.write_line(b'HELO example') self.write_line(b'EHLO example') self.assertEqual(self.channel.socket.last, b'503 Duplicate HELO/EHLO\r\n') def test_HELP(self): self.write_line(b'HELP') self.assertEqual(self.channel.socket.last, b'250 Supported commands: EHLO HELO MAIL RCPT ' + \ b'DATA RSET NOOP QUIT VRFY\r\n') def test_HELP_command(self): self.write_line(b'HELP MAIL') self.assertEqual(self.channel.socket.last, b'250 Syntax: MAIL FROM:
\r\n') def test_HELP_command_unknown(self): self.write_line(b'HELP SPAM') self.assertEqual(self.channel.socket.last, b'501 Supported commands: EHLO HELO MAIL RCPT ' + \ b'DATA RSET NOOP QUIT VRFY\r\n') def test_HELO_bad_syntax(self): self.write_line(b'HELO') self.assertEqual(self.channel.socket.last, b'501 Syntax: HELO hostname\r\n') def test_HELO_duplicate(self): self.write_line(b'HELO example') self.write_line(b'HELO example') self.assertEqual(self.channel.socket.last, b'503 Duplicate HELO/EHLO\r\n') def test_HELO_parameter_rejected_when_extensions_not_enabled(self): self.extended_smtp = False self.write_line(b'HELO example') self.write_line(b'MAIL from: SIZE=1234') self.assertEqual(self.channel.socket.last, b'501 Syntax: MAIL FROM:
\r\n') def test_MAIL_allows_space_after_colon(self): self.write_line(b'HELO example') self.write_line(b'MAIL from: ') self.assertEqual(self.channel.socket.last, b'250 OK\r\n') def test_extended_MAIL_allows_space_after_colon(self): self.write_line(b'EHLO example') self.write_line(b'MAIL from: size=20') self.assertEqual(self.channel.socket.last, b'250 OK\r\n') def test_NOOP(self): self.write_line(b'NOOP') self.assertEqual(self.channel.socket.last, b'250 OK\r\n') def test_HELO_NOOP(self): self.write_line(b'HELO example') self.write_line(b'NOOP') self.assertEqual(self.channel.socket.last, b'250 OK\r\n') def test_NOOP_bad_syntax(self): self.write_line(b'NOOP hi') self.assertEqual(self.channel.socket.last, b'501 Syntax: NOOP\r\n') def test_QUIT(self): self.write_line(b'QUIT') self.assertEqual(self.channel.socket.last, b'221 Bye\r\n') def test_HELO_QUIT(self): self.write_line(b'HELO example') self.write_line(b'QUIT') self.assertEqual(self.channel.socket.last, b'221 Bye\r\n') def test_QUIT_arg_ignored(self): self.write_line(b'QUIT bye bye') self.assertEqual(self.channel.socket.last, b'221 Bye\r\n') def test_bad_state(self): self.channel.smtp_state = 'BAD STATE' self.write_line(b'HELO example') self.assertEqual(self.channel.socket.last, b'451 Internal confusion\r\n') def test_command_too_long(self): self.write_line(b'HELO example') self.write_line(b'MAIL from: ' + b'a' * self.channel.command_size_limit + b'@example') self.assertEqual(self.channel.socket.last, b'500 Error: line too long\r\n') def test_MAIL_command_limit_extended_with_SIZE(self): self.write_line(b'EHLO example') fill_len = self.channel.command_size_limit - len('MAIL from:<@example>') self.write_line(b'MAIL from:<' + b'a' * fill_len + b'@example> SIZE=1234') self.assertEqual(self.channel.socket.last, b'250 OK\r\n') self.write_line(b'MAIL from:<' + b'a' * (fill_len + 26) + b'@example> SIZE=1234') self.assertEqual(self.channel.socket.last, b'500 Error: line too long\r\n') def test_data_longer_than_default_data_size_limit(self): # Hack the default so we don't have to generate so much data. self.channel.data_size_limit = 1048 self.write_line(b'HELO example') self.write_line(b'MAIL From:eggs@example') self.write_line(b'RCPT To:spam@example') self.write_line(b'DATA') self.write_line(b'A' * self.channel.data_size_limit + b'A\r\n.') self.assertEqual(self.channel.socket.last, b'552 Error: Too much mail data\r\n') def test_MAIL_size_parameter(self): self.write_line(b'EHLO example') self.write_line(b'MAIL FROM: SIZE=512') self.assertEqual(self.channel.socket.last, b'250 OK\r\n') def test_MAIL_invalid_size_parameter(self): self.write_line(b'EHLO example') self.write_line(b'MAIL FROM: SIZE=invalid') self.assertEqual(self.channel.socket.last, b'501 Syntax: MAIL FROM:
[SP ]\r\n') def test_MAIL_RCPT_unknown_parameters(self): self.write_line(b'EHLO example') self.write_line(b'MAIL FROM: ham=green') self.assertEqual(self.channel.socket.last, b'555 MAIL FROM parameters not recognized or not implemented\r\n') self.write_line(b'MAIL FROM:') self.write_line(b'RCPT TO: ham=green') self.assertEqual(self.channel.socket.last, b'555 RCPT TO parameters not recognized or not implemented\r\n') def test_MAIL_size_parameter_larger_than_default_data_size_limit(self): self.channel.data_size_limit = 1048 self.write_line(b'EHLO example') self.write_line(b'MAIL FROM: SIZE=2096') self.assertEqual(self.channel.socket.last, b'552 Error: message size exceeds fixed maximum message size\r\n') def test_need_MAIL(self): self.write_line(b'HELO example') self.write_line(b'RCPT to:spam@example') self.assertEqual(self.channel.socket.last, b'503 Error: need MAIL command\r\n') def test_MAIL_syntax_HELO(self): self.write_line(b'HELO example') self.write_line(b'MAIL from eggs@example') self.assertEqual(self.channel.socket.last, b'501 Syntax: MAIL FROM:
\r\n') def test_MAIL_syntax_EHLO(self): self.write_line(b'EHLO example') self.write_line(b'MAIL from eggs@example') self.assertEqual(self.channel.socket.last, b'501 Syntax: MAIL FROM:
[SP ]\r\n') def test_MAIL_missing_address(self): self.write_line(b'HELO example') self.write_line(b'MAIL from:') self.assertEqual(self.channel.socket.last, b'501 Syntax: MAIL FROM:
\r\n') def test_MAIL_chevrons(self): self.write_line(b'HELO example') self.write_line(b'MAIL from:') self.assertEqual(self.channel.socket.last, b'250 OK\r\n') def test_MAIL_empty_chevrons(self): self.write_line(b'EHLO example') self.write_line(b'MAIL from:<>') self.assertEqual(self.channel.socket.last, b'250 OK\r\n') def test_MAIL_quoted_localpart(self): self.write_line(b'EHLO example') self.write_line(b'MAIL from: <"Fred Blogs"@example.com>') self.assertEqual(self.channel.socket.last, b'250 OK\r\n') self.assertEqual(self.channel.mailfrom, '"Fred Blogs"@example.com') def test_MAIL_quoted_localpart_no_angles(self): self.write_line(b'EHLO example') self.write_line(b'MAIL from: "Fred Blogs"@example.com') self.assertEqual(self.channel.socket.last, b'250 OK\r\n') self.assertEqual(self.channel.mailfrom, '"Fred Blogs"@example.com') def test_MAIL_quoted_localpart_with_size(self): self.write_line(b'EHLO example') self.write_line(b'MAIL from: <"Fred Blogs"@example.com> SIZE=1000') self.assertEqual(self.channel.socket.last, b'250 OK\r\n') self.assertEqual(self.channel.mailfrom, '"Fred Blogs"@example.com') def test_MAIL_quoted_localpart_with_size_no_angles(self): self.write_line(b'EHLO example') self.write_line(b'MAIL from: "Fred Blogs"@example.com SIZE=1000') self.assertEqual(self.channel.socket.last, b'250 OK\r\n') self.assertEqual(self.channel.mailfrom, '"Fred Blogs"@example.com') def test_nested_MAIL(self): self.write_line(b'HELO example') self.write_line(b'MAIL from:eggs@example') self.write_line(b'MAIL from:spam@example') self.assertEqual(self.channel.socket.last, b'503 Error: nested MAIL command\r\n') def test_VRFY(self): self.write_line(b'VRFY eggs@example') self.assertEqual(self.channel.socket.last, b'252 Cannot VRFY user, but will accept message and attempt ' + \ b'delivery\r\n') def test_VRFY_syntax(self): self.write_line(b'VRFY') self.assertEqual(self.channel.socket.last, b'501 Syntax: VRFY
\r\n') def test_EXPN_not_implemented(self): self.write_line(b'EXPN') self.assertEqual(self.channel.socket.last, b'502 EXPN not implemented\r\n') def test_no_HELO_MAIL(self): self.write_line(b'MAIL from:') self.assertEqual(self.channel.socket.last, b'503 Error: send HELO first\r\n') def test_need_RCPT(self): self.write_line(b'HELO example') self.write_line(b'MAIL From:eggs@example') self.write_line(b'DATA') self.assertEqual(self.channel.socket.last, b'503 Error: need RCPT command\r\n') def test_RCPT_syntax_HELO(self): self.write_line(b'HELO example') self.write_line(b'MAIL From: eggs@example') self.write_line(b'RCPT to eggs@example') self.assertEqual(self.channel.socket.last, b'501 Syntax: RCPT TO:
\r\n') def test_RCPT_syntax_EHLO(self): self.write_line(b'EHLO example') self.write_line(b'MAIL From: eggs@example') self.write_line(b'RCPT to eggs@example') self.assertEqual(self.channel.socket.last, b'501 Syntax: RCPT TO:
[SP ]\r\n') def test_RCPT_lowercase_to_OK(self): self.write_line(b'HELO example') self.write_line(b'MAIL From: eggs@example') self.write_line(b'RCPT to: ') self.assertEqual(self.channel.socket.last, b'250 OK\r\n') def test_no_HELO_RCPT(self): self.write_line(b'RCPT to eggs@example') self.assertEqual(self.channel.socket.last, b'503 Error: send HELO first\r\n') def test_data_dialog(self): self.write_line(b'HELO example') self.write_line(b'MAIL From:eggs@example') self.assertEqual(self.channel.socket.last, b'250 OK\r\n') self.write_line(b'RCPT To:spam@example') self.assertEqual(self.channel.socket.last, b'250 OK\r\n') self.write_line(b'DATA') self.assertEqual(self.channel.socket.last, b'354 End data with .\r\n') self.write_line(b'data\r\nmore\r\n.') self.assertEqual(self.channel.socket.last, b'250 OK\r\n') self.assertEqual(self.server.messages, [('peer', 'eggs@example', ['spam@example'], 'data\nmore')]) def test_DATA_syntax(self): self.write_line(b'HELO example') self.write_line(b'MAIL From:eggs@example') self.write_line(b'RCPT To:spam@example') self.write_line(b'DATA spam') self.assertEqual(self.channel.socket.last, b'501 Syntax: DATA\r\n') def test_no_HELO_DATA(self): self.write_line(b'DATA spam') self.assertEqual(self.channel.socket.last, b'503 Error: send HELO first\r\n') def test_data_transparency_section_4_5_2(self): self.write_line(b'HELO example') self.write_line(b'MAIL From:eggs@example') self.write_line(b'RCPT To:spam@example') self.write_line(b'DATA') self.write_line(b'..\r\n.\r\n') self.assertEqual(self.channel.received_data, '.') def test_multiple_RCPT(self): self.write_line(b'HELO example') self.write_line(b'MAIL From:eggs@example') self.write_line(b'RCPT To:spam@example') self.write_line(b'RCPT To:ham@example') self.write_line(b'DATA') self.write_line(b'data\r\n.') self.assertEqual(self.server.messages, [('peer', 'eggs@example', ['spam@example','ham@example'], 'data')]) def test_manual_status(self): # checks that the Channel is able to return a custom status message self.write_line(b'HELO example') self.write_line(b'MAIL From:eggs@example') self.write_line(b'RCPT To:spam@example') self.write_line(b'DATA') self.write_line(b'return status\r\n.') self.assertEqual(self.channel.socket.last, b'250 Okish\r\n') def test_RSET(self): self.write_line(b'HELO example') self.write_line(b'MAIL From:eggs@example') self.write_line(b'RCPT To:spam@example') self.write_line(b'RSET') self.assertEqual(self.channel.socket.last, b'250 OK\r\n') self.write_line(b'MAIL From:foo@example') self.write_line(b'RCPT To:eggs@example') self.write_line(b'DATA') self.write_line(b'data\r\n.') self.assertEqual(self.server.messages, [('peer', 'foo@example', ['eggs@example'], 'data')]) def test_HELO_RSET(self): self.write_line(b'HELO example') self.write_line(b'RSET') self.assertEqual(self.channel.socket.last, b'250 OK\r\n') def test_RSET_syntax(self): self.write_line(b'RSET hi') self.assertEqual(self.channel.socket.last, b'501 Syntax: RSET\r\n') def test_unknown_command(self): self.write_line(b'UNKNOWN_CMD') self.assertEqual(self.channel.socket.last, b'500 Error: command "UNKNOWN_CMD" not ' + \ b'recognized\r\n') def test_attribute_deprecations(self): with support.check_warnings(('', DeprecationWarning)): spam = self.channel._SMTPChannel__server with support.check_warnings(('', DeprecationWarning)): self.channel._SMTPChannel__server = 'spam' with support.check_warnings(('', DeprecationWarning)): spam = self.channel._SMTPChannel__line with support.check_warnings(('', DeprecationWarning)): self.channel._SMTPChannel__line = 'spam' with support.check_warnings(('', DeprecationWarning)): spam = self.channel._SMTPChannel__state with support.check_warnings(('', DeprecationWarning)): self.channel._SMTPChannel__state = 'spam' with support.check_warnings(('', DeprecationWarning)): spam = self.channel._SMTPChannel__greeting with support.check_warnings(('', DeprecationWarning)): self.channel._SMTPChannel__greeting = 'spam' with support.check_warnings(('', DeprecationWarning)): spam = self.channel._SMTPChannel__mailfrom with support.check_warnings(('', DeprecationWarning)): self.channel._SMTPChannel__mailfrom = 'spam' with support.check_warnings(('', DeprecationWarning)): spam = self.channel._SMTPChannel__rcpttos with support.check_warnings(('', DeprecationWarning)): self.channel._SMTPChannel__rcpttos = 'spam' with support.check_warnings(('', DeprecationWarning)): spam = self.channel._SMTPChannel__data with support.check_warnings(('', DeprecationWarning)): self.channel._SMTPChannel__data = 'spam' with support.check_warnings(('', DeprecationWarning)): spam = self.channel._SMTPChannel__fqdn with support.check_warnings(('', DeprecationWarning)): self.channel._SMTPChannel__fqdn = 'spam' with support.check_warnings(('', DeprecationWarning)): spam = self.channel._SMTPChannel__peer with support.check_warnings(('', DeprecationWarning)): self.channel._SMTPChannel__peer = 'spam' with support.check_warnings(('', DeprecationWarning)): spam = self.channel._SMTPChannel__conn with support.check_warnings(('', DeprecationWarning)): self.channel._SMTPChannel__conn = 'spam' with support.check_warnings(('', DeprecationWarning)): spam = self.channel._SMTPChannel__addr with support.check_warnings(('', DeprecationWarning)): self.channel._SMTPChannel__addr = 'spam' def test_decode_data_default_warning(self): server = DummyServer((support.HOST, 0), ('b', 0)) conn, addr = self.server.accept() with self.assertWarns(DeprecationWarning): smtpd.SMTPChannel(server, conn, addr) @unittest.skipUnless(support.IPV6_ENABLED, "IPv6 not enabled") class SMTPDChannelIPv6Test(SMTPDChannelTest): def setUp(self): smtpd.socket = asyncore.socket = mock_socket self.old_debugstream = smtpd.DEBUGSTREAM self.debug = smtpd.DEBUGSTREAM = io.StringIO() self.server = DummyServer((support.HOSTv6, 0), ('b', 0)) conn, addr = self.server.accept() self.channel = smtpd.SMTPChannel(self.server, conn, addr, decode_data=True) class SMTPDChannelWithDataSizeLimitTest(unittest.TestCase): def setUp(self): smtpd.socket = asyncore.socket = mock_socket self.old_debugstream = smtpd.DEBUGSTREAM self.debug = smtpd.DEBUGSTREAM = io.StringIO() self.server = DummyServer((support.HOST, 0), ('b', 0)) conn, addr = self.server.accept() # Set DATA size limit to 32 bytes for easy testing self.channel = smtpd.SMTPChannel(self.server, conn, addr, 32, decode_data=True) def tearDown(self): asyncore.close_all() asyncore.socket = smtpd.socket = socket smtpd.DEBUGSTREAM = self.old_debugstream def write_line(self, line): self.channel.socket.queue_recv(line) self.channel.handle_read() def test_data_limit_dialog(self): self.write_line(b'HELO example') self.write_line(b'MAIL From:eggs@example') self.assertEqual(self.channel.socket.last, b'250 OK\r\n') self.write_line(b'RCPT To:spam@example') self.assertEqual(self.channel.socket.last, b'250 OK\r\n') self.write_line(b'DATA') self.assertEqual(self.channel.socket.last, b'354 End data with .\r\n') self.write_line(b'data\r\nmore\r\n.') self.assertEqual(self.channel.socket.last, b'250 OK\r\n') self.assertEqual(self.server.messages, [('peer', 'eggs@example', ['spam@example'], 'data\nmore')]) def test_data_limit_dialog_too_much_data(self): self.write_line(b'HELO example') self.write_line(b'MAIL From:eggs@example') self.assertEqual(self.channel.socket.last, b'250 OK\r\n') self.write_line(b'RCPT To:spam@example') self.assertEqual(self.channel.socket.last, b'250 OK\r\n') self.write_line(b'DATA') self.assertEqual(self.channel.socket.last, b'354 End data with .\r\n') self.write_line(b'This message is longer than 32 bytes\r\n.') self.assertEqual(self.channel.socket.last, b'552 Error: Too much mail data\r\n') class SMTPDChannelWithDecodeDataFalse(unittest.TestCase): def setUp(self): smtpd.socket = asyncore.socket = mock_socket self.old_debugstream = smtpd.DEBUGSTREAM self.debug = smtpd.DEBUGSTREAM = io.StringIO() self.server = DummyServer((support.HOST, 0), ('b', 0), decode_data=False) conn, addr = self.server.accept() # Set decode_data to False self.channel = smtpd.SMTPChannel(self.server, conn, addr, decode_data=False) def tearDown(self): asyncore.close_all() asyncore.socket = smtpd.socket = socket smtpd.DEBUGSTREAM = self.old_debugstream def write_line(self, line): self.channel.socket.queue_recv(line) self.channel.handle_read() def test_ascii_data(self): self.write_line(b'HELO example') self.write_line(b'MAIL From:eggs@example') self.write_line(b'RCPT To:spam@example') self.write_line(b'DATA') self.write_line(b'plain ascii text') self.write_line(b'.') self.assertEqual(self.channel.received_data, b'plain ascii text') def test_utf8_data(self): self.write_line(b'HELO example') self.write_line(b'MAIL From:eggs@example') self.write_line(b'RCPT To:spam@example') self.write_line(b'DATA') self.write_line(b'utf8 enriched text: \xc5\xbc\xc5\xba\xc4\x87') self.write_line(b'and some plain ascii') self.write_line(b'.') self.assertEqual( self.channel.received_data, b'utf8 enriched text: \xc5\xbc\xc5\xba\xc4\x87\n' b'and some plain ascii') class SMTPDChannelWithDecodeDataTrue(unittest.TestCase): def setUp(self): smtpd.socket = asyncore.socket = mock_socket self.old_debugstream = smtpd.DEBUGSTREAM self.debug = smtpd.DEBUGSTREAM = io.StringIO() self.server = DummyServer((support.HOST, 0), ('b', 0), decode_data=True) conn, addr = self.server.accept() # Set decode_data to True self.channel = smtpd.SMTPChannel(self.server, conn, addr, decode_data=True) def tearDown(self): asyncore.close_all() asyncore.socket = smtpd.socket = socket smtpd.DEBUGSTREAM = self.old_debugstream def write_line(self, line): self.channel.socket.queue_recv(line) self.channel.handle_read() def test_ascii_data(self): self.write_line(b'HELO example') self.write_line(b'MAIL From:eggs@example') self.write_line(b'RCPT To:spam@example') self.write_line(b'DATA') self.write_line(b'plain ascii text') self.write_line(b'.') self.assertEqual(self.channel.received_data, 'plain ascii text') def test_utf8_data(self): self.write_line(b'HELO example') self.write_line(b'MAIL From:eggs@example') self.write_line(b'RCPT To:spam@example') self.write_line(b'DATA') self.write_line(b'utf8 enriched text: \xc5\xbc\xc5\xba\xc4\x87') self.write_line(b'and some plain ascii') self.write_line(b'.') self.assertEqual( self.channel.received_data, 'utf8 enriched text: żźć\nand some plain ascii') if __name__ == "__main__": unittest.main()