fix: hbar transfer

Signed-off-by: prajeeta pal <prajeetapal@gmail.com>

Author: prajeeta15

CHANGELOG.md

@@ -46,6 +46,10 @@ This changelog is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.
 
 - fixed workflow: changelog check with improved sensitivity to deletions, additions, new releases
 
+### Breaking Changes
+
+- Changed error message in `TransferTransaction._add_hbar_transfer()` and `AbstractTokenTransferTransaction._add_token_transfer()` when amount is zero from "Amount must be a non-zero integer" to "Amount must be a non-zero value." for clarity and consistency.
+
 ## [0.1.9] - 2025-11-26
 
 ### Added

src/hiero_sdk_python/tokens/abstract_token_transfer_transaction.py

@@ -149,7 +149,7 @@ def _add_token_transfer(
         if not isinstance(account_id, AccountId):
             raise TypeError("account_id must be an AccountId instance.")
         if not isinstance(amount, int) or amount == 0:
-            raise ValueError("Amount must be a non-zero integer.")
+            raise ValueError("Amount must be a non-zero value.")
         if expected_decimals is not None and not isinstance(expected_decimals, int):
             raise TypeError("expected_decimals must be an integer.")
         if not isinstance(is_approved, bool):

tests/integration/transfer_transaction_e2e_test.py

@@ -7,6 +7,7 @@
 from hiero_sdk_python.crypto.private_key import PrivateKey
 from hiero_sdk_python.exceptions import PrecheckError
 from hiero_sdk_python.hbar import Hbar
+from hiero_sdk_python.hbar_unit import HbarUnit
 from hiero_sdk_python.query.account_balance_query import CryptoGetAccountBalanceQuery
 from hiero_sdk_python.response_code import ResponseCode
 from hiero_sdk_python.tokens.nft_id import NftId
@@ -448,3 +449,47 @@ def test_integration_transfer_transaction_approved_token_transfer():
 
     finally:
         env.close()
+
+
+@pytest.mark.integration
+def test_integration_transfer_transaction_with_hbar_units():
+    env = IntegrationTestEnv()
+
+    try:
+        new_account_private_key = PrivateKey.generate()
+        new_account_public_key = new_account_private_key.public_key()
+
+        initial_balance = Hbar(1)
+
+        account_transaction = AccountCreateTransaction(
+            key=new_account_public_key, initial_balance=initial_balance, memo="Recipient Account"
+        )
+
+        receipt = account_transaction.execute(env.client)
+
+        assert (
+            receipt.status == ResponseCode.SUCCESS
+        ), f"Account creation failed with status: {ResponseCode(receipt.status).name}"
+
+        account_id = receipt.account_id
+        assert account_id is not None
+
+        transfer_transaction = TransferTransaction()
+        transfer_transaction.add_hbar_transfer(env.operator_id, Hbar(-1.5, HbarUnit.HBAR))
+        transfer_transaction.add_hbar_transfer(account_id, Hbar(1.5, HbarUnit.HBAR))
+
+        receipt = transfer_transaction.execute(env.client)
+
+        assert (
+            receipt.status == ResponseCode.SUCCESS
+        ), f"Transfer failed with status: {ResponseCode(receipt.status).name}"
+
+        query_transaction = CryptoGetAccountBalanceQuery(account_id)
+        balance = query_transaction.execute(env.client)
+
+        expected_balance_tinybars = Hbar(1).to_tinybars() + Hbar(1.5, HbarUnit.HBAR).to_tinybars()
+        assert (
+            balance and balance.hbars.to_tinybars() == expected_balance_tinybars
+        ), f"Expected balance: {expected_balance_tinybars}, actual balance: {balance.hbars.to_tinybars()}"
+    finally:
+        env.close()

tests/unit/test_transfer_transaction.py

@@ -284,11 +284,11 @@ def test_zero_amount_validation(mock_account_ids):
     transfer_tx = TransferTransaction()
 
     # Test zero HBAR amount should raise ValueError
-    with pytest.raises(ValueError, match="Amount must be a non-zero integer"):
+    with pytest.raises(ValueError, match="Amount must be a non-zero value"):
         transfer_tx.add_hbar_transfer(account_id_1, 0)
 
     # Test zero token amount should raise ValueError
-    with pytest.raises(ValueError, match="Amount must be a non-zero integer"):
+    with pytest.raises(ValueError, match="Amount must be a non-zero value"):
         transfer_tx.add_token_transfer(token_id_1, account_id_1, 0)