diff --git a/test/unit/test_state.py b/test/unit/test_state.py
new file mode 100644
index 0000000..348f852
--- /dev/null
+++ b/test/unit/test_state.py
@@ -0,0 +1,108 @@
+import threading
+import signal
+import pytest
+import mock
+
+from robot_interface.state import State
+
+
+def test_initialize_does_not_reinitialize():
+    """
+    Check that calling `initialize` on an already initialized state does not change existing
+    attributes.
+    """
+    state = State()
+    
+    # Mock qi_session to avoid real session creation
+    mock_session = mock.MagicMock()
+    state.qi_session = mock_session
+    
+    # Set state as already initialized
+    state.is_initialized = True
+    old_exit_event = state.exit_event
+    
+    # Call initialize
+    state.initialize()
+    
+    # Ensure existing attributes were not overwritten
+    assert state.exit_event == old_exit_event  # exit_event should not be recreated
+    assert state.qi_session == mock_session    # qi_session should not be replaced
+    assert state.is_initialized is True        # is_initialized should remain True
+
+
+def test_deinitialize_behavior():
+    """Check that deinitialize closes sockets and updates the initialization state correctly."""
+    state = State()
+    
+    # Case 1: Initialized with sockets
+    state.is_initialized = True
+    mock_socket_1 = mock.Mock()
+    mock_socket_2 = mock.Mock()
+    state.sockets = [mock_socket_1, mock_socket_2]
+    state.deinitialize()
+    
+    # Sockets should be closed
+    mock_socket_1.close.assert_called_once()
+    mock_socket_2.close.assert_called_once()
+    # State should be marked as not initialized
+    assert not state.is_initialized
+
+    # Case 2: Not initialized, should not raise
+    state.is_initialized = False
+    state.sockets = []
+    state.deinitialize()
+    assert not state.is_initialized
+
+
+def test_access_control_before_initialization():
+    """Verify that accessing certain attributes before initialization raises RuntimeError."""
+    state = State()
+    
+    with pytest.raises(RuntimeError, match=".*sockets.*"):
+        _ = state.sockets
+    
+    with pytest.raises(RuntimeError, match=".*qi_session.*"):
+        _ = state.qi_session
+
+
+def test_exit_event_before_initialized_returns_if_set():
+    """Check that exit_event can be accessed even if state is not initialized, 
+    but only if it is set."""
+    state = State()
+    
+    # Manually create and set the exit_event
+    object.__setattr__(state, "exit_event", threading.Event())
+    object.__getattribute__(state, "exit_event").set()
+    
+    # Should return the event without raising
+    assert state.exit_event.is_set()
+
+
+def test_getattribute_allowed_attributes_before_init():
+    """Ensure attributes allowed before initialization can be accessed without error."""
+    state = State()
+    
+    assert callable(state.initialize)
+    assert callable(state.deinitialize)
+    assert state.is_initialized is False
+    assert state.__dict__ is not None
+    assert state.__class__.__name__ == "State"
+    assert state.__doc__ is not None
+
+
+def test_signal_handler_sets_exit_event(monkeypatch):
+    """Ensure SIGINT triggers the exit_event via signal handler."""
+    state = State()
+    
+    # Patch get_qi_session to prevent real session creation
+    monkeypatch.setattr("robot_interface.state.get_qi_session", lambda: "dummy_session")
+    
+    # Initialize state to set up signal handlers
+    state.initialize()
+    
+    # Simulate SIGINT
+    signal_handler = signal.getsignal(signal.SIGINT)
+    signal_handler(None, None)
+    
+    # Exit event should be set
+    assert state.exit_event.is_set()