tests/test_blacklist_check.py

@@ -2,6 +2,7 @@ from unittest.case import TestCase
 
 from validate_email.domainlist_check import (
     domainlist_check, update_builtin_blacklist)
+from validate_email.email_address import EmailAddress
 from validate_email.exceptions import DomainBlacklistedError
 from validate_email.validate_email import (
     validate_email, validate_email_or_fail)
@@ -16,7 +17,7 @@ class BlacklistCheckTestCase(TestCase):
     def test_blacklist_positive(self):
         'Disallows blacklist item: mailinator.com.'
         with self.assertRaises(DomainBlacklistedError):
-            domainlist_check(user_part='pa2', domain_part='mailinator.com')
+            domainlist_check(EmailAddress('pa2@mailinator.com'))
         with self.assertRaises(DomainBlacklistedError):
             validate_email_or_fail(
                 email_address='pa2@mailinator.com', check_regex=False,
@@ -37,5 +38,4 @@ class BlacklistCheckTestCase(TestCase):
     def test_blacklist_negative(self):
         'Allows a domain not in the blacklist.'
         self.assertTrue(expr=domainlist_check(
-            user_part='pa2',
-            domain_part='some-random-domain-thats-not-blacklisted.com'))
+            EmailAddress('pa2@some-random-domain-thats-not-blacklisted.com')))

tests/test_email_address.py

@@ -0,0 +1,68 @@
+from unittest.case import TestCase
+
+from validate_email import validate_email
+from validate_email.email_address import EmailAddress
+from validate_email.exceptions import AddressFormatError
+
+
+class UserDomainTestCase(TestCase):
+    'Test the split of an email address into user and domain.'
+
+    valid_tests = {
+        'email@domain.com': ('email', 'domain.com'),
+        'email@subdomain.domain.com': ('email', 'subdomain.domain.com'),
+        'email@123.123.123.123': ('email', '123.123.123.123'),
+        'email@[123.123.123.123]': ('email', '[123.123.123.123]'),
+        'email@domain-one.com': ('email', 'domain-one.com'),
+        'email@domain.co.jp': ('email', 'domain.co.jp'),
+    }
+
+    invalid_tests = [
+        'plainaddress',  # missing @ sign and domain
+        'email.domain.com',  # missing @
+    ]
+
+    def test_user_domain_valid(self):
+        'Splits email address into user and domain parts.'
+        for address, (user, domain) in self.valid_tests.items():
+            self.assertEqual(EmailAddress(address).user, user)
+            self.assertEqual(EmailAddress(address).domain, domain)
+
+    def test_user_domain_invalid(self):
+        'Rejects unparseable email address.'
+        for address in self.invalid_tests:
+            # This must be rejected directly by the EmailAddress constructor...
+            with self.assertRaises(AddressFormatError) as exc:
+                EmailAddress(address)
+            self.assertTupleEqual(exc.exception.args, ())
+            # ...and indirectly by validate_email().
+            self.assertFalse(validate_email(address))
+
+
+class IdnaTestCase(TestCase):
+    'Testing IDNA conversion.'
+
+    valid_tests = {
+        'email@address.com': 'email@address.com',
+        'email@motörhéád.com': 'email@xn--motrhd-tta7d3f.com',
+        'email@[123.123.123.123]': ('email@[123.123.123.123]'),
+    }
+
+    invalid_tests = [
+        'test@♥web.de',
+    ]
+
+    def test_idna_conversion_valid(self):
+        'Converts email address into ASCII-compatible encoding.'
+        for address, ace in self.valid_tests.items():
+            self.assertEqual(EmailAddress(address).ace, ace)
+
+    def test_idna_conversion_invalid(self):
+        'Rejects email address which is not IDNA-convertible.'
+        for address in self.invalid_tests:
+            # This must be rejected directly by the EmailAddress constructor...
+            with self.assertRaises(AddressFormatError) as exc:
+                EmailAddress(address)
+            self.assertTupleEqual(exc.exception.args, ())
+            # ...and indirectly by validate_email().
+            self.assertFalse(validate_email(address))

tests/test_mx_check.py

@@ -5,19 +5,8 @@ from unittest.mock import Mock, patch
 from dns.exception import Timeout
 
 from validate_email import mx_check as mx_module
-from validate_email.exceptions import (
-    AddressFormatError, DNSTimeoutError, NoValidMXError)
-from validate_email.mx_check import (
-    _dissect_email, _get_idna_address, _get_mx_records)
-
-DOMAINS = {
-    'email@domain.com': 'domain.com',
-    'email@subdomain.domain.com': 'subdomain.domain.com',
-    'email@123.123.123.123': '123.123.123.123',
-    'email@[123.123.123.123]': '123.123.123.123',
-    'email@domain-one.com': 'domain-one.com',
-    'email@domain.co.jp': 'domain.co.jp',
-}
+from validate_email.exceptions import DNSTimeoutError, NoValidMXError
+from validate_email.mx_check import _get_mx_records
 
 
 class DnsNameStub(object):
@@ -33,30 +22,6 @@ class DnsNameStub(object):
 TEST_QUERY = Mock()
 
 
-class DomainTestCase(TestCase):
-
-    def test_domain_from_email_address(self):
-        for address, domain in DOMAINS.items():
-            _user, domain_from_function = _dissect_email(email_address=address)
-            self.assertEqual(domain_from_function, domain)
-
-
-class IdnaTestCase(TestCase):
-    'Testing IDNA converting.'
-
-    def test_resolves_idna_domains(self):
-        'Resolves email@motörhéád.com.'
-        self.assertEqual(
-            first=_get_idna_address(email_address='email@motörhéád.com'),
-            second='email@xn--motrhd-tta7d3f.com')
-
-    def test_resolves_conventional_domains(self):
-        'Resolves email@address.com.'
-        self.assertEqual(
-            first=_get_idna_address(email_address='email@address.com'),
-            second='email@address.com')
-
-
 class GetMxRecordsTestCase(TestCase):
     'Testing `_get_mx_records`.'
 
@@ -97,10 +62,3 @@ class GetMxRecordsTestCase(TestCase):
         with self.assertRaises(DNSTimeoutError) as exc:
             _get_mx_records(domain='testdomain3', timeout=10)
         self.assertTupleEqual(exc.exception.args, ())
-
-    def test_returns_false_on_idna_failure(self):
-        'Returns `False` on IDNA failure.'
-        with self.assertRaises(AddressFormatError) as exc:
-            mx_module.mx_check(
-                email_address='test@♥web.de', from_address='mail@example.com')
-        self.assertTupleEqual(exc.exception.args, ())

tests/test_regex_check.py

@@ -1,8 +1,8 @@
 from unittest.case import TestCase
 
+from validate_email.email_address import EmailAddress
 from validate_email.exceptions import AddressFormatError
 from validate_email.regex_check import regex_check
-from validate_email.validate_email import validate_email
 
 VALID_EXAMPLES = [
     'email@domain.com',  # basic valid email
@@ -35,11 +35,6 @@ INVALID_EXAMPLES = [
     'email@domain..com',  # multiple dot in the domain portion is invalid
 ]
 
-UNPARSEABLE_EXAMPLES = [
-    'plainaddress',  # missing @ sign and domain
-    'email.domain.com',  # missing @
-]
-
 
 class FormatValidity(TestCase):
     'Testing regex validation + format validity.'
@@ -47,21 +42,14 @@ class FormatValidity(TestCase):
     def test_valid_email_structure_regex(self):
         'Accepts an email with a valid structure.'
         for address in VALID_EXAMPLES:
-            user_part, domain_part = address.rsplit('@', 1)
             self.assertTrue(
-                expr=regex_check(user_part=user_part, domain_part=domain_part),
+                expr=regex_check(EmailAddress(address)),
                 msg=f'Check is not true with {address}')
 
     def test_invalid_email_structure_regex(self):
         'Rejects an email with an invalid structure.'
         for address in INVALID_EXAMPLES:
-            user_part, domain_part = address.rsplit('@', 1)
             with self.assertRaises(
                     expected_exception=AddressFormatError,
                     msg=f'Test failed for {address}'):
-                regex_check(user_part=user_part, domain_part=domain_part),
-
-    def test_unparseable_email(self):
-        'Rejects an unparseable email.'
-        for address in UNPARSEABLE_EXAMPLES:
-            self.assertFalse(expr=validate_email(email_address=address))
+                regex_check(EmailAddress(address))

validate_email/constants.py

@@ -5,7 +5,6 @@ HOST_REGEX = re_compile(
     # max length for domain name labels is 63 characters per RFC 1034
     r'((?:[A-Z0-9](?:[A-Z0-9-]{0,61}[A-Z0-9])?\.)+)'
     r'(?:[A-Z0-9-]{2,63}(?<!-))\Z', IGNORECASE)
-EMAIL_EXTRACT_HOST_REGEX = re_compile(r'(?<=@)\[?([^\[\]]+)')
 LITERAL_REGEX = re_compile(
     # literal form, ipv4 or ipv6 address (SMTP 4.1.3)
     r'\[([A-f0-9:\.]+)\]\Z', IGNORECASE)

validate_email/domainlist_check.py

@@ -3,6 +3,7 @@ from typing import Optional
 
 from filelock import FileLock
 
+from .email_address import EmailAddress
 from .exceptions import DomainBlacklistedError
 from .updater import (
     BLACKLIST_FILEPATH_INSTALLED, BLACKLIST_FILEPATH_TMP, LOCK_PATH,
@@ -55,11 +56,11 @@ class DomainListValidator(object):
         self.domain_blacklist = set(
             x.strip().lower() for x in lines if x.strip())
 
-    def __call__(self, user_part: str, domain_part: str) -> bool:
+    def __call__(self, address: EmailAddress) -> bool:
         'Do the checking here.'
-        if domain_part in self.domain_whitelist:
+        if address.domain in self.domain_whitelist:
             return True
-        if domain_part in self.domain_blacklist:
+        if address.domain in self.domain_blacklist:
             raise DomainBlacklistedError
         return True
 

validate_email/email_address.py

@@ -0,0 +1,60 @@
+from idna.core import IDNAError, encode
+
+from .exceptions import AddressFormatError
+
+
+class EmailAddress(object):
+    """
+    Internally used class to hold an email address.
+
+    This class featuers splitting the email address into user and domain
+    part as well as converting internationalized domain name into the
+    ASCII-compatible encoding (ACE) according to the IDNA standard.
+    """
+
+    def __init__(self, address: str):
+        self._address = address
+
+        # Split email address into user and domain part.