test: add unit test for subscription_handle

CHANGELOG.md

@@ -7,6 +7,7 @@ This changelog is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.
 ## [Unreleased]
 
 ### Added
+- Added unit tests for `SubscriptionHandle` class covering cancellation state, thread management, and join operations.
 - Modularized `transfer_transaction_fungible` example by introducing `account_balance_query()` & `transfer_transaction()`.Renamed `transfer_tokens()` → `main()`
 - Phase 2 of the inactivity-unassign bot:Automatically detects stale open pull requests (no commit activity for 21+ days), comments with a helpful InactivityBot message, closes the stale PR, and unassigns the contributor from the linked issue.
 - Added **str**() to CustomFixedFee and updated examples and tests accordingly.

CONTRIBUTING.md

@@ -166,4 +166,25 @@ Thank you for contributing to the Hiero Python SDK! 🎉
 - **Need help or want to connect?** Join our community on Discord! See the **[Discord Joining Guide](docs/discord.md)** for detailed steps on how to join the LFDT server
 - **Quick Links:**
     - Join the main [Linux Foundation Decentralized Trust (LFDT) Discord Server](https://discord.gg/hyperledger).
-    - Go directly to the [#hiero-python-sdk channel](https://discord.com/channels/905194001349627914/1336494517544681563)
+    - Go directly to the [#hiero-python-sdk channel](https://discord.com/channels/905194001349627914/1336494517544681563)
+
+---
+
+## Running tests locally
+
+During development you may want to run a single test file in isolation to avoid importing the project's package-level `__init__` (which imports generated protobuf modules). To run a single test file without loading project-wide fixtures, use the project's virtualenv Python and run pytest on the path:
+
+PowerShell example:
+```powershell
+# activate virtualenv (if not already active)
+C:/Users/Giannis/OneDrive/Programming/hiero-sdk-python/.venv/Scripts/Activate.ps1
+
+# install test deps if needed
+python -m pip install -U pip
+python -m pip install pytest
+
+# run a single test file
+python -m pytest -q tests/test_subscription_handle.py
+```
+
+If you want to run a subset of tests, use `-k` with a keyword expression or provide a directory/file path. This helps avoid heavy `conftest.py` imports during quick iteration.

tests/_shims/hiero_sdk_python/hapi/__init__.py

@@ -0,0 +1,5 @@
+"""Test shims for generated `hapi` modules.
+
+These are minimal stand-ins used during unit testing when the real
+generated protobuf/grpc modules are not present.
+"""

tests/_shims/hiero_sdk_python/hapi/mirror/__init__.py

@@ -0,0 +1 @@
+"""Shim for `hiero_sdk_python.hapi.mirror` used in tests."""

tests/_shims/hiero_sdk_python/hapi/mirror/consensus_service_pb2_grpc.py

@@ -0,0 +1,7 @@
+"""Minimal stub of generated gRPC module used by `client.Client` for tests."""
+
+class ConsensusServiceStub:
+    """A tiny stub of the real gRPC stub. Methods are intentionally omitted."""
+
+    def __init__(self, channel):
+        self._channel = channel

tests/_shims/hiero_sdk_python/hapi/services/__init__.py

@@ -0,0 +1 @@
+"""Shim for `hiero_sdk_python.hapi.services` providing minimal protobuf stubs for tests."""

tests/_shims/hiero_sdk_python/hapi/services/basic_types_pb2.py

@@ -0,0 +1,13 @@
+"""Minimal shim for basic_types_pb2 used in tests."""
+
+class _ProtoMessage:
+    def CopyFrom(self, other):
+        for k, v in getattr(other, "__dict__", {}).items():
+            setattr(self, k, v)
+
+
+class TransactionID(_ProtoMessage):
+    def __init__(self):
+        self.accountID = _ProtoMessage()
+        self.transactionValidStart = _ProtoMessage()
+        self.scheduled = False

tests/_shims/hiero_sdk_python/hapi/services/timestamp_pb2.py

@@ -0,0 +1,6 @@
+"""Minimal shim for timestamp_pb2.Timestamp used in tests."""
+
+class Timestamp:
+    def __init__(self, seconds: int = 0, nanos: int = 0):
+        self.seconds = int(seconds)
+        self.nanos = int(nanos)

tests/unit/test_subscription_handle.py

@@ -0,0 +1,28 @@
+from unittest.mock import Mock
+
+from hiero_sdk_python.utils.subscription_handle import SubscriptionHandle
+
+
+def test_not_cancelled_by_default():
+    handle = SubscriptionHandle()
+    assert not handle.is_cancelled()
+
+
+def test_cancel_marks_as_cancelled():
+    handle = SubscriptionHandle()
+    handle.cancel()
+    assert handle.is_cancelled()
+
+
+def test_set_thread_and_join_calls_thread_join_with_timeout():
+    handle = SubscriptionHandle()
+    mock_thread = Mock()
+    handle.set_thread(mock_thread)
+    handle.join(timeout=0.25)
+    mock_thread.join.assert_called_once_with(0.25)
+
+
+def test_join_without_thread_raises_nothing():
+    handle = SubscriptionHandle()
+    # should not raise
+    handle.join()

tools/_mypy_minimal.ini

@@ -0,0 +1,2 @@
+[mypy]
+ignore_missing_imports = True