add User.get_by_atproto_did

models.py

@@ -138,6 +138,28 @@ def get_by_id(cls, id):
 
         return user
 
+    @staticmethod
+    def get_by_atproto_did(did):
+        """Fetches the user across all protocols with the given atproto_did.
+
+        If more than one user has the given atproto_did, this returns an
+        arbitrary one!
+
+        Args:
+          did: str
+
+        Returns:
+          :class:`User` subclass instance, or None if not found
+        """
+        assert did
+
+        for cls in set(PROTOCOLS.values()):
+            if not cls:
+                continue
+            user = cls.query(cls.atproto_did == did).get()
+            if user:
+                return user
+
     @classmethod
     @ndb.transactional()
     def get_or_create(cls, id, **kwargs):

tests/test_models.py

@@ -53,6 +53,11 @@ def test_validate_atproto_did(self):
         user.atproto_did = 'did:plc:123'
         user.atproto_did = None
 
+    def test_get_by_atproto_did(self):
+        self.assertIsNone(User.get_by_atproto_did('did:plc:foo'))
+        user = self.make_user('fake:user', cls=Fake, atproto_did='did:plc:foo')
+        self.assertEqual(user, User.get_by_atproto_did('did:plc:foo'))
+
     def test_get_or_create_use_instead(self):
         user = Fake.get_or_create('a.b')
         user.use_instead = g.user.key
@@ -155,7 +160,6 @@ def test_target_hashable(self):
 
         # just check that these don't crash
         assert isinstance(id(target), int)
-        {target: 'foo'}
 
     def test_ndb_in_memory_cache_off(self):
         """It has a weird bug that we want to avoid.