Add BaseEntity.username property

Returns username from handle or None.

federation/entities/mixins.py

@@ -1,6 +1,7 @@
 import datetime
 import importlib
 import warnings
+from typing import Optional
 
 from federation.entities.activitypub.enums import ActivityType
 
@@ -115,6 +116,14 @@ class BaseEntity:
         """Implement in subclasses if needed."""
         pass
 
+    @property
+    def username(self) -> Optional[str]:
+        if self.handle:
+            username_part = self.handle.rsplit('@', 1)
+            if username_part:
+                # Strip any remaining '@' if this is a Mastodon style handle
+                return username_part[0].strip('@')
+
 
 class PublicMixin(BaseEntity):
     public = False

federation/tests/entities/test_base.py

@@ -18,6 +18,16 @@ class TestPostEntityTags:
         assert post.tags == set()
 
 
+class TestBaseEntity:
+    def test_username(self):
+        entity = Profile(handle='foobar@localhost.local')
+        assert entity.username == 'foobar'
+        entity = Profile(handle='@foobar@localhost.local')
+        assert entity.username == 'foobar'
+        entity = Profile()
+        assert entity.username is None
+
+
 class TestBaseEntityCallsValidateMethods:
     def test_entity_calls_attribute_validate_method(self):
         post = PostFactory()