add invalidation tests

tests/test_gates.py

@@ -21,3 +21,11 @@ def test_non_unitary_gate():
     non_unitary_gate = np.array([[2, 0], [0, 0.5]])
     with pytest.raises(ValueError):
         Gates._validate_gate(non_unitary_gate)
+
+
+def test_create_controlled_gate_invalid_qubits():
+    # Define a scenario where the control and target qubits are out of range
+    with pytest.raises(IndexError):
+        Gates.create_controlled_gate(
+            Gates.X, control_qubit=4, target_qubit=5, num_qubits=3
+        )

tests/test_simulator.py

@@ -202,12 +202,25 @@ def test_invalid_qubit_index():
         simulator.h(2)  # Index out of range
 
 
+def test_reset_invalid_qubit_index():
+    simulator = QubitSimulator(3)
+    simulator.num_qubits = -1  # Set an invalid value for num_qubits
+    with pytest.raises(ValueError):
+        simulator.reset()  # Resetting with an invalid value should raise an error
+
+
 def test_invalid_control_and_target_index():
     simulator = QubitSimulator(1)
     with pytest.raises(IndexError):
         simulator.cx(1, 0)  # Control qubit cannot be out of range
 
 
+def test_apply_gate_invalid_control_qubit():
+    simulator = QubitSimulator(1)
+    with pytest.raises(IndexError):
+        simulator._apply_gate("X", Gates.X, target_qubit=0, control_qubit=2)
+
+
 def test_error_messages():
     with pytest.raises(ValueError, match="Number of qubits must be non-negative."):
         QubitSimulator(-1)