py3-validate-email/tests/test_smtp_check.py

131 lines
5.4 KiB
Python

from smtplib import SMTPServerDisconnected
from socket import timeout
from ssl import SSLError
from unittest.case import TestCase
from unittest.mock import patch
from validate_email.email_address import EmailAddress
from validate_email.exceptions import (
AddressNotDeliverableError, SMTPCommunicationError, SMTPMessage,
SMTPTemporaryError)
from validate_email.smtp_check import _SMTPChecker, smtp_check
class SMTPMock(_SMTPChecker):
"""
Mock replacement for the SMTP connection.
Instead of really communicating with an SMTP server, this class
works with predefined fake responses. By default, the responses
emulate a successful SMTP conversation, but it can be turned into an
unsuccessful one by patching the `reply` dictionary.
"""
reply = {
None: (220, b'Welcome'),
"EHLO": (502, b'Please use HELO'),
'HELO': (220, b'HELO successful'),
'MAIL': (250, b'MAIL FROM successful'),
'RCPT': (250, b'RCPT TO successful'),
'QUIT': (221, b'QUIT successful'),
# This is not a real life response, only for mocking
'STARTTLS': (220, b'Welcome'),
}
last_command = None
def _get_socket(self, host, port, timeout):
return None
def send(self, s):
self.last_command = s.split()[0].upper()
def getreply(self):
if isinstance(self.reply[self.last_command], Exception):
self.close()
raise self.reply[self.last_command]
return self.reply[self.last_command]
def mocked_starttls(self: SMTPMock, *args, **kwargs):
'Mocking `starttls()` to raise `SSLError`.'
(resp, reply) = self.docmd('STARTTLS')
raise SSLError('param 1', 'param 2')
class SMTPCheckTest(TestCase):
'Collection of tests the `smtp_check` method.'
# All the possible ways to fail we want to test, listed as tuples
# containing (command, reply, expected exception).
failures = [
# Timeout on connection
(None, timeout(), SMTPTemporaryError),
# Connection unexpectedly closed during any stage
(None, SMTPServerDisconnected('Test'), SMTPTemporaryError),
('EHLO', SMTPServerDisconnected('Test'), SMTPTemporaryError),
('HELO', SMTPServerDisconnected('Test'), SMTPTemporaryError),
('MAIL', SMTPServerDisconnected('Test'), SMTPTemporaryError),
('RCPT', SMTPServerDisconnected('Test'), SMTPTemporaryError),
# Temporary error codes
(None, (421, b'Connect failed'), SMTPTemporaryError),
('HELO', (421, b'HELO failed'), SMTPTemporaryError),
('MAIL', (451, b'MAIL FROM failed'), SMTPTemporaryError),
('RCPT', (451, b'RCPT TO failed'), SMTPTemporaryError),
# Permanent error codes
(None, (554, b'Connect failed'), SMTPCommunicationError),
('HELO', (504, b'HELO failed'), SMTPCommunicationError),
('MAIL', (550, b'MAIL FROM failed'), SMTPCommunicationError),
('RCPT', (550, b'RCPT TO failed'), AddressNotDeliverableError),
]
@patch(target='validate_email.smtp_check._SMTPChecker', new=SMTPMock)
def test_smtp_success(self):
'Succeeds on successful SMTP conversation'
self.assertTrue(
smtp_check(
email_address=EmailAddress('alice@example.com'),
mx_records=['smtp.example.com'],
)
)
def _test_one_smtp_failure(self, cmd, reply, exception):
with patch.dict(in_dict=SMTPMock.reply, values={cmd: reply}):
with self.assertRaises(exception) as context:
smtp_check(
email_address=EmailAddress('alice@example.com'),
mx_records=['smtp.example.com'])
if isinstance(reply, tuple):
error_messages = context.exception.error_messages
error_info = error_messages['smtp.example.com']
self.assertEqual(error_info.command[:4].upper(), cmd or 'CONN')
self.assertEqual(error_info.code, reply[0])
self.assertEqual(error_info.text, reply[1].decode())
@patch(target='validate_email.smtp_check._SMTPChecker', new=SMTPMock)
def test_smtp_failure(self):
'Fails on unsuccessful SMTP conversation.'
for cmd, reply, exception in self.failures:
with self.subTest(cmd=cmd, reply=reply):
self._test_one_smtp_failure(cmd, reply, exception)
@patch(target='validate_email.smtp_check._SMTPChecker', new=SMTPMock)
@patch(target='smtplib.SMTP.starttls', new=mocked_starttls)
def test_ssl_error(self):
'Handles an `SSLError` during `starttls()` properly.'
with self.assertRaises(SMTPTemporaryError) as context:
smtp_check(
email_address=EmailAddress('alice@example.com'),
mx_records=['smtp.example.com'])
exc = context.exception
error_text = (
'During TLS negotiation, the following exception(s) happened: '
"SSLError('param 1', 'param 2')")
smtp_message = \
exc.error_messages['smtp.example.com'] # type: SMTPMessage
self.assertIs(type(smtp_message), SMTPMessage)
self.assertEqual(smtp_message.text, error_text)
self.assertEqual(smtp_message.command, 'STARTTLS')
self.assertEqual(smtp_message.code, -1)
error = smtp_message.exceptions[0]
self.assertIs(type(error), SSLError)
self.assertTupleEqual(error.args, ('param 1', 'param 2'))