added edge cases on test suite

Author: ericksc

tests/test_email_control_character.py

@@ -0,0 +1,9 @@
+"""HU-02: reject SOH in an address intended for SMTP (RFC 5321)."""
+import validators
+
+
+def test_email_rejects_soh_control_character():
+    # The Python escape introduces the actual ASCII SOH character.
+    email = '"user\x01name"@example.com'
+    result = validators.email(email)
+    assert isinstance(result, validators.ValidationError), repr(result)

tests/test_email_ipv6_literal.py

@@ -0,0 +1,9 @@
+"""HU-02: accept the IPv6: prefix in an SMTP address literal."""
+import validators
+
+
+def test_email_accepts_ipv6_literal_with_prefix():
+    result = validators.email(
+        "usuario@[IPv6:2001:db8::1]", ipv6_address=True
+    )
+    assert result is True, repr(result)

tests/test_email_quoted_at_sign.py

@@ -0,0 +1,7 @@
+"""HU-02: accept @ inside a quoted local part."""
+import validators
+
+
+def test_email_accepts_at_sign_inside_quoted_local_part():
+    result = validators.email('"user@name"@example.com')
+    assert result is True, repr(result)

tests/test_ipv4_strict_cidr.py

@@ -0,0 +1,8 @@
+"""HU-04: require a prefix length in the documented strict CIDR mode."""
+import validators
+
+
+def test_ipv4_strict_cidr_rejects_dotted_netmask():
+    # The network is valid, but its representation is not CIDR prefix notation.
+    result = validators.ipv4("192.168.1.0/255.255.255.0", strict=True)
+    assert isinstance(result, validators.ValidationError), repr(result)

tests/test_ipv6_brackets.py

@@ -0,0 +1,10 @@
+"""HU-04: proposed enhancement; brackets are URL host syntax.
+
+This test expresses a new requirement, not a defect in the current contract.
+"""
+import validators
+
+
+def test_ipv6_accepts_address_in_brackets():
+    result = validators.ipv6("[2001:db8::1]")
+    assert result is True, repr(result)