move get_custom_domain() to alias_utils

app/alias_utils.py

@@ -27,6 +27,7 @@ from app.models import (
     Mailbox,
     EmailLog,
     Contact,
+    SLDomain,
 )
 from app.regex_utils import regex_match
 
@@ -274,3 +275,15 @@ def check_alias_prefix(alias_prefix) -> bool:
         return False
 
     return True
+
+
+def get_custom_domain(alias_address) -> Optional[CustomDomain]:
+    alias_domain = validate_email(
+        alias_address, check_deliverability=False, allow_smtputf8=False
+    ).domain
+
+    # handle the case a SLDomain is also a CustomDomain
+    if SLDomain.get_by(domain=alias_domain) is None:
+        custom_domain = CustomDomain.get_by(domain=alias_domain)
+        if custom_domain:
+            return custom_domain

app/api/views/new_custom_alias.py

@@ -1,11 +1,9 @@
-from typing import Optional
-
-from email_validator import validate_email, EmailNotValidError
+from email_validator import EmailNotValidError
 from flask import g
 from flask import jsonify, request
 from itsdangerous import SignatureExpired
 
-from app.alias_utils import check_alias_prefix
+from app.alias_utils import check_alias_prefix, get_custom_domain
 from app.api.base import api_bp, require_api_auth
 from app.api.serializer import (
     serialize_alias_info_v2,
@@ -20,28 +18,14 @@ from app.models import (
     Alias,
     AliasUsedOn,
     User,
-    CustomDomain,
     DeletedAlias,
     DomainDeletedAlias,
     Mailbox,
     AliasMailbox,
-    SLDomain,
 )
 from app.utils import convert_to_id
 
 
-def get_custom_domain(alias_address) -> Optional[CustomDomain]:
-    alias_domain = validate_email(
-        alias_address, check_deliverability=False, allow_smtputf8=False
-    ).domain
-
-    # handle the case a SLDomain is also a CustomDomain
-    if SLDomain.get_by(domain=alias_domain) is None:
-        custom_domain = CustomDomain.get_by(domain=alias_domain)
-        if custom_domain:
-            return custom_domain
-
-
 @api_bp.route("/v2/alias/custom/new", methods=["POST"])
 @limiter.limit(ALIAS_LIMIT)
 @require_api_auth