Improving error handling for null values

lbry/lbry/schema/claim.py

@@ -124,7 +124,12 @@ class BaseClaim:
             for field in self.object_fields:
                 if key.startswith(f'{field}_'):
                     attr = getattr(self, field)
-                    setattr(attr, key[len(f'{field}_'):], kwargs.pop(key))
+
+                    attr_value = kwargs.pop(key)
+                    if attr_value is None:
+                        raise ValueError(f"Error updating claim - Null value provided for attribute {field}")
+                    
+                    setattr(attr, key[len(f'{field}_'):], attr_value)
                     continue
 
         for l in self.repeat_fields:

lbry/tests/unit/schema/test_models.py

@@ -1,7 +1,8 @@
 from unittest import TestCase
+from unittest.mock import patch
 from decimal import Decimal
 
-from lbry.schema.claim import Claim, Stream, Collection
+from lbry.schema.claim import Claim, Stream, Collection, BaseClaim
 
 
 class TestClaimContainerAwareness(TestCase):
@@ -195,3 +196,21 @@ class TestLocations(TestCase):
         stream = Stream()
         stream.locations.append({"country": "UA"})
         self.assertEqual(stream.locations[0].country, 'UA')
+
+
+class TestBaseClaimUpdates(TestCase):
+
+    @patch('lbry.schema.claim.Claim')
+    def test_claim_update_url_ok(self, MockClaim):
+        # test if an attribute is provided correctly
+        base_claim = BaseClaim(MockClaim)
+        base_claim.update(thumbnail_url="somescheme:some/path")
+        self.assertEqual(base_claim.thumbnail.url, "somescheme:some/path")
+
+    @patch('lbry.schema.claim.Claim')
+    def test_claim_update_url_error(self, MockClaim):
+        # test if an attribute is null
+        base_claim = BaseClaim(MockClaim)
+        with self.assertRaisesRegex(ValueError, "Error updating claim - Null value provided for attribute thumbnail"):
+            base_claim.update(thumbnail_url=None)
+