models: Create get_first_human_user function in Realm.

zerver/models.py

@@ -639,6 +639,17 @@ class Realm(models.Model):
         # TODO: Change return type to QuerySet[UserProfile]
         return UserProfile.objects.filter(realm=self, is_active=True).select_related()
 
+    def get_first_human_user(self) -> Optional["UserProfile"]:
+        """A useful value for communications with newly created realms.
+        Has a few fundamental limitations:
+
+        * Its value will be effectively random for realms imported from Slack or
+          other third-party tools.
+        * The user may be deactivated, etc., so it's not something that's useful
+          for features, permissions, etc.
+        """
+        return UserProfile.objects.filter(realm=self, is_bot=False).order_by("id").first()
+
     def get_human_owner_users(self) -> QuerySet:
         return UserProfile.objects.filter(
             realm=self, is_bot=False, role=UserProfile.ROLE_REALM_OWNER, is_active=True

zerver/tests/test_users.py

@@ -134,6 +134,24 @@ class PermissionTest(ZulipTestCase):
         admin_users = user_profile.realm.get_admin_users_and_bots(include_realm_owners=False)
         self.assertFalse(user_profile in admin_users)
 
+    def test_get_first_human_user(self) -> None:
+        realm = get_realm("zulip")
+        UserProfile.objects.filter(realm=realm).delete()
+
+        UserProfile.objects.create(
+            realm=realm, email="bot1@zulip.com", delivery_email="bot1@zulip.com", is_bot=True
+        )
+        first_human_user = UserProfile.objects.create(
+            realm=realm, email="user1@zulip.com", delivery_email="user1@zulip.com", is_bot=False
+        )
+        UserProfile.objects.create(
+            realm=realm, email="user2@zulip.com", delivery_email="user2@zulip.com", is_bot=False
+        )
+        UserProfile.objects.create(
+            realm=realm, email="bot2@zulip.com", delivery_email="bot2@zulip.com", is_bot=True
+        )
+        self.assertEqual(first_human_user, realm.get_first_human_user())
+
     def test_updating_non_existent_user(self) -> None:
         self.login("hamlet")
         admin = self.example_user("hamlet")