test(send_reply): close coverage gaps in SendReply

tests/test_send_reply.py

@@ -22,9 +22,10 @@ def mock_address() -> Generator[None, None, None]:
         os.environ["DBUS_SESSION_BUS_ADDRESS"] = original_address
 
 
-def test_send_reply_exception() -> None:
-    """Test that SendReply sends an error message when DBusError is raised."""
-
+@pytest.fixture
+def send_reply_setup() -> Generator[
+    tuple[BaseMessageBus, Message, list[Message]], None, None
+]:
     messages: list[Message] = []
 
     class MockClosable:
@@ -43,11 +44,23 @@ def _setup_socket(self) -> None:
             self._stream = MockClosable()  # type: ignore
 
     with patch("socket.socket.connect"):
-        mock_message_bus = MockBus()
-    mock_message = Message(
+        bus = MockBus()
+    msg = Message(
         path="/test/path", interface="test.interface", member="test_member", serial=1
     )
-    send_reply = SendReply(mock_message_bus, mock_message)
+    try:
+        yield bus, msg, messages
+    finally:
+        bus.disconnect()
+        bus._finalize(None)
+
+
+def test_send_reply_exception(
+    send_reply_setup: tuple[BaseMessageBus, Message, list[Message]],
+) -> None:
+    """Test that SendReply sends an error message when DBusError is raised."""
+    bus, msg, messages = send_reply_setup
+    send_reply = SendReply(bus, msg)
 
     with send_reply:
         raise DBusError(ErrorType.DISCONNECTED, "Disconnected", None)
@@ -57,43 +70,60 @@ def _setup_socket(self) -> None:
     assert messages[0].error_name == "org.freedesktop.DBus.Error.Disconnected"
     assert messages[0].reply_serial == 1
 
-    mock_message_bus.disconnect()
-    mock_message_bus._finalize(None)
 
+def test_send_reply_generic_exception(
+    send_reply_setup: tuple[BaseMessageBus, Message, list[Message]],
+) -> None:
+    """Non-DBusError exceptions become SERVICE_ERROR replies."""
+    bus, msg, messages = send_reply_setup
+    send_reply = SendReply(bus, msg)
 
-def test_send_reply_happy_path() -> None:
-    """Test that SendReply sends a message."""
+    with send_reply:
+        raise RuntimeError("boom")
 
-    messages: list[Message] = []
+    assert len(messages) == 1
+    assert messages[0].message_type == MessageType.ERROR
+    assert messages[0].error_name == ErrorType.SERVICE_ERROR.value
+    assert messages[0].reply_serial == 1
+    assert "boom" in messages[0].body[0]
 
-    class MockClosable:
-        def close(self) -> None:
-            pass
 
-    class MockBus(BaseMessageBus):
-        def send(self, msg: Message) -> None:
-            messages.append(msg)
+def test_send_reply_send_error(
+    send_reply_setup: tuple[BaseMessageBus, Message, list[Message]],
+) -> None:
+    """send_error() routes an exception through the same error reply path."""
+    bus, msg, messages = send_reply_setup
+    send_reply = SendReply(bus, msg)
 
-        def send_message(self, msg: Message) -> None:
-            messages.append(msg)
+    send_reply.send_error(DBusError(ErrorType.FAILED, "explicit failure", None))
 
-        def _setup_socket(self) -> None:
-            self._sock = MockClosable()  # type: ignore
-            self._stream = MockClosable()  # type: ignore
+    assert len(messages) == 1
+    assert messages[0].message_type == MessageType.ERROR
+    assert messages[0].error_name == "org.freedesktop.DBus.Error.Failed"
+    assert messages[0].reply_serial == 1
 
-    with patch("socket.socket.connect"):
-        mock_message_bus = MockBus()
-    mock_message = Message(
-        path="/test/path", interface="test.interface", member="test_member", serial=1
-    )
-    send_reply = SendReply(mock_message_bus, mock_message)
+
+def test_send_reply_no_exception_returns_false(
+    send_reply_setup: tuple[BaseMessageBus, Message, list[Message]],
+) -> None:
+    """Exiting with no exception must not suppress and must not send a reply."""
+    bus, msg, messages = send_reply_setup
+    send_reply = SendReply(bus, msg)
+
+    assert send_reply._exit(None, None, None) is False
+    assert messages == []
+
+
+def test_send_reply_happy_path(
+    send_reply_setup: tuple[BaseMessageBus, Message, list[Message]],
+) -> None:
+    """Test that SendReply sends a message."""
+    bus, msg, messages = send_reply_setup
+    send_reply = SendReply(bus, msg)
 
     with send_reply as reply:
-        reply(mock_message)
+        reply(msg)
 
     assert len(messages) == 1
     assert messages[0].message_type == MessageType.METHOD_CALL
     assert messages[0].error_name is None
-
-    mock_message_bus.disconnect()
-    mock_message_bus._finalize(None)