fix: avoid storing non-holders in TokenHolders batch

batch/indexer_token_holders.py

@@ -194,6 +194,16 @@ def collect(self):
             local_session.close()
 
     def __update_status(self, local_session: Session, status: TokenHolderBatchStatus):
+        if status == TokenHolderBatchStatus.DONE:
+            # Not to store non-holders
+            (
+                local_session.query(TokenHolder).
+                filter(TokenHolder.holder_list_id == self.target.id).
+                filter(TokenHolder.hold_balance == 0).
+                filter(TokenHolder.locked_balance == 0).
+                delete()
+            )
+
         self.target.batch_status = status.value
         local_session.merge(self.target)
         LOG.info(f"Token holder list({self.target.list_id}) status changes to be {status.value}.")

tests/test_batch_indexer_token_holders.py

@@ -1205,6 +1205,15 @@ def test_normal_9(
         block_number = web3.eth.block_number
         _token_holders_list = token_holders_list(token_contract.address, block_number, list_id)
         db.add(_token_holders_list)
+        db.flush()
+
+        former_holder = TokenHolder()
+        former_holder.holder_list_id = _token_holders_list.id
+        former_holder.hold_balance = 0
+        former_holder.locked_balance = 0
+        former_holder.account_address = "former holder"
+        db.add(former_holder)
+
         db.commit()
 
         # Issuer transfers issued token to user1 again to proceed block_number on chain.