Merge pull request #2 from ericksc/feature/hu02-email

HU-02: Reject ASCII control characters in quoted email local parts

Author: ericksc

src/validators/email.py

@@ -93,8 +93,8 @@ def email(
             + r"(\.[\u0100-\u017F\u0180-\u024F\u00A0-\u00FF0-9a-z!#$%&'*+/=?^_`{}|~\-]+)*$"
             # quoted-string
             + r'|^"('
-            + r"[\u0100-\u017F\u0180-\u024F\u00A0-\u00FF\001-\010\013\014\016-\037"
-            + r"!#-\[\]-\177]|\\[\011.]"
+            + r"[\u0100-\u017F\u0180-\u024F\u00A0-\u00FF"
+            + r"!#-\[\]-~]|\\[\011.]"
             + r')*")$',
             username_part,
             re.IGNORECASE,

tests/test_email_control_character.py

@@ -1,4 +1,4 @@
-"""HU-02: reject SOH in an address intended for SMTP (RFC 5321)."""
+"""HU-02: reject ASCII control characters in quoted SMTP local parts."""
 
 # external
 import pytest
@@ -7,12 +7,14 @@
 
 
 @pytest.mark.parametrize(
-    ("email",),
-    [
-        ('"user\x01name"@example.com', ),
-    ],
+    "control_code",
+        [1, 2, 7, 11, 12, 14, 27, 31, 127],
 )
-def test_email_rejects_soh_control_character(email: str):
-    """The Python escape introduces the actual ASCII SOH character."""
+
+def test_email_rejects_control_characters(control_code: int):
+    """Reject selected ASCII control characters in quoted local parts."""
+    email = f'"user{chr(control_code)}name"@example.com'
+
     result = validators.email(email)
+
     assert isinstance(result, validators.ValidationError), repr(result)