models: Refactor get_fake_email_domain to take realm.host as arg.

This commit updates get_fake_email_domain to accept realm.host as
argument instead of the Realm object since we only use realm.host
to get the fake email domain.

This is a preparatory commit for the limited guest feature as we
would be sending the fake email of the message sender in message
event object to a guest user who cannot access the sender and
there we would need to compute the fake email.

zerver/actions/users.py

@@ -80,7 +80,7 @@ def do_delete_user(user_profile: UserProfile, *, acting_user: Optional[UserProfi
         replacement_user = create_user(
             force_id=user_id,
             email=Address(
-                username=f"deleteduser{user_id}", domain=get_fake_email_domain(realm)
+                username=f"deleteduser{user_id}", domain=get_fake_email_domain(realm.host)
             ).addr_spec,
             password=None,
             realm=realm,
@@ -186,7 +186,7 @@ def do_delete_user_preserving_messages(user_profile: UserProfile) -> None:
         # is cleaner by using the same re-assignment approach for them together with Messages.
         random_token = secrets.token_hex(16)
         temp_replacement_user = create_user(
-            email=f"temp_deleteduser{random_token}@{get_fake_email_domain(realm)}",
+            email=f"temp_deleteduser{random_token}@{get_fake_email_domain(realm.host)}",
             password=None,
             realm=realm,
             full_name=f"Deleted User {user_id} (temp)",
@@ -206,7 +206,7 @@ def do_delete_user_preserving_messages(user_profile: UserProfile) -> None:
 
         replacement_user = create_user(
             force_id=user_id,
-            email=f"deleteduser{user_id}@{get_fake_email_domain(realm)}",
+            email=f"deleteduser{user_id}@{get_fake_email_domain(realm.host)}",
             password=None,
             realm=realm,
             full_name=f"Deleted User {user_id}",

zerver/lib/create_user.py

@@ -70,7 +70,7 @@ def copy_default_settings(
 def get_display_email_address(user_profile: UserProfile) -> str:
     if not user_profile.email_address_is_realm_public():
         return Address(
-            username=f"user{user_profile.id}", domain=get_fake_email_domain(user_profile.realm)
+            username=f"user{user_profile.id}", domain=get_fake_email_domain(user_profile.realm.host)
         ).addr_spec
     return user_profile.delivery_email
 

zerver/lib/users.py

@@ -796,7 +796,9 @@ def get_cross_realm_dicts() -> List[APIUserDict]:
 
 
 def get_data_for_inaccessible_user(realm: Realm, user_id: int) -> APIUserDict:
-    fake_email = Address(username=f"user{user_id}", domain=get_fake_email_domain(realm)).addr_spec
+    fake_email = Address(
+        username=f"user{user_id}", domain=get_fake_email_domain(realm.host)
+    ).addr_spec
 
     # We just set date_joined field to UNIX epoch.
     user_date_joined = timestamp_to_datetime(0)

zerver/models.py

@@ -995,7 +995,7 @@ class Realm(models.Model):  # type: ignore[django-manager-missing] # django-stub
         )
 
     def get_bot_domain(self) -> str:
-        return get_fake_email_domain(self)
+        return get_fake_email_domain(self.host)
 
     def get_notifications_stream(self) -> Optional["Stream"]:
         if self.notifications_stream is not None and not self.notifications_stream.deactivated:
@@ -5194,11 +5194,11 @@ class InvalidFakeEmailDomainError(Exception):
     pass
 
 
-def get_fake_email_domain(realm: Realm) -> str:
+def get_fake_email_domain(realm_host: str) -> str:
     try:
         # Check that realm.host can be used to form valid email addresses.
-        validate_email(Address(username="bot", domain=realm.host).addr_spec)
+        validate_email(Address(username="bot", domain=realm_host).addr_spec)
-        return realm.host
+        return realm_host
     except ValidationError:
         pass
 

zerver/tests/test_users.py

@@ -2820,27 +2820,27 @@ class DeleteUserTest(ZulipTestCase):
 class FakeEmailDomainTest(ZulipTestCase):
     def test_get_fake_email_domain(self) -> None:
         realm = get_realm("zulip")
-        self.assertEqual("zulip.testserver", get_fake_email_domain(realm))
+        self.assertEqual("zulip.testserver", get_fake_email_domain(realm.host))
 
         with self.settings(EXTERNAL_HOST="example.com"):
-            self.assertEqual("zulip.example.com", get_fake_email_domain(realm))
+            self.assertEqual("zulip.example.com", get_fake_email_domain(realm.host))
 
     @override_settings(FAKE_EMAIL_DOMAIN="fakedomain.com", REALM_HOSTS={"zulip": "127.0.0.1"})
     def test_get_fake_email_domain_realm_host_is_ip_addr(self) -> None:
         realm = get_realm("zulip")
-        self.assertEqual("fakedomain.com", get_fake_email_domain(realm))
+        self.assertEqual("fakedomain.com", get_fake_email_domain(realm.host))
 
     @override_settings(FAKE_EMAIL_DOMAIN="invaliddomain", REALM_HOSTS={"zulip": "127.0.0.1"})
     def test_invalid_fake_email_domain(self) -> None:
         realm = get_realm("zulip")
         with self.assertRaises(InvalidFakeEmailDomainError):
-            get_fake_email_domain(realm)
+            get_fake_email_domain(realm.host)
 
     @override_settings(FAKE_EMAIL_DOMAIN="127.0.0.1", REALM_HOSTS={"zulip": "127.0.0.1"})
     def test_invalid_fake_email_domain_ip(self) -> None:
         with self.assertRaises(InvalidFakeEmailDomainError):
             realm = get_realm("zulip")
-            get_fake_email_domain(realm)
+            get_fake_email_domain(realm.host)
 
 
 class TestBulkRegenerateAPIKey(ZulipTestCase):