✅ Improved Test Coverage

src/mqt/predictor/evaluation.py

@@ -25,7 +25,7 @@
 logger = logging.getLogger("mqt-predictor")
 
 
-def create_qiskit_result(qc: QuantumCircuit, device: dict[str, Any] | None = None) -> Result:
+def create_qiskit_result(qc: QuantumCircuit, device: dict[str, Any]) -> Result:
     """Creates a Result object for a given benchmark and device using qiskit for compilation.
 
     Args:
@@ -35,7 +35,6 @@ def create_qiskit_result(qc: QuantumCircuit, device: dict[str, Any] | None = Non
     Returns:
         Result: Returns a Result object containing the compiled quantum circuit.
     """
-    assert device is not None
     if qc.num_qubits > device["max_qubits"]:
         return Result("qiskit_", -1, None, device["name"])
     start_time = time.time()
@@ -56,7 +55,7 @@ def create_qiskit_result(qc: QuantumCircuit, device: dict[str, Any] | None = Non
 
 def create_tket_result(
     qc: QuantumCircuit,
-    device: dict[str, Any] | None = None,
+    device: dict[str, Any],
 ) -> Result:
     """Creates a Result object for a given benchmark and device using tket for compilation.
 
@@ -67,7 +66,6 @@ def create_tket_result(
     Returns:
         Result: Returns a Result object containing the compiled quantum circuit.
     """
-    assert device is not None
     if qc.num_qubits > device["max_qubits"]:
         return Result("tket_" + device["name"], -1, None, device["name"])
     tket_qc = qiskit_to_tk(qc)

src/mqt/predictor/ml/helper.py

@@ -238,7 +238,7 @@ def save_training_data(
 
 def load_training_data(
     figure_of_merit: reward.figure_of_merit = "expected_fidelity",
-) -> tuple[NDArray[np.float_], list[str], list[NDArray[np.float_]]]:
+) -> tuple[list[NDArray[np.float_]], list[str], list[NDArray[np.float_]]]:
     """Loads and returns the training data from the training data folder.
 
     Args:

tests/compilation/test_helper_rl.py

@@ -31,6 +31,14 @@ def test_get_action_terminate() -> None:
 def test_get_actions_devices() -> None:
     assert len(rl.helper.get_devices()) == rl.helper.NUM_ACTIONS_DEVICES
 
+    with pytest.raises(RuntimeError):
+        rl.helper.get_device("false_input")
+
+
+def test_get_device_index_of_device_false_input() -> None:
+    with pytest.raises(RuntimeError):
+        rl.helper.get_device_index_of_device("false_input")
+
 
 def test_get_actions_mapping() -> None:
     assert len(rl.helper.get_actions_mapping()) == rl.helper.NUM_ACTIONS_MAPPING

tests/device_selection/test_helper_ml.py

@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+import pytest
+
 from mqt.bench import benchmark_generator
 from mqt.predictor import ml, qcompile
 
@@ -20,12 +22,23 @@ def test_get_index_to_device_LUT() -> None:
 def test_load_training_data() -> None:
     assert ml.helper.load_training_data() is not None
 
+    with pytest.raises(FileNotFoundError, match="Training data not found. Please run the training script first."):
+        ml.helper.load_training_data("false_input")  # type: ignore[arg-type]
+
+
+def test_save_training_data() -> None:
+    training_data, names_list, scores_list = ml.helper.load_training_data()
+    ml.helper.save_training_data(training_data, names_list, scores_list, "expected_fidelity")
+
 
 def test_create_feature_dict() -> None:
     qc = benchmark_generator.get_benchmark("dj", 1, 3)
     feature_vector = ml.helper.create_feature_dict(qc)
     assert feature_vector is not None
 
+    with pytest.raises(ValueError, match="Invalid input for 'qc' parameter."):
+        ml.helper.create_feature_dict("false_input")
+
 
 def test_get_openqasm_gates() -> None:
     assert ml.helper.get_openqasm_gates() is not None
@@ -66,3 +79,9 @@ def test_qcompile() -> None:
     assert quantum_device in ml.helper.get_index_to_device_LUT().values()
     assert qc_compiled.layout is not None
     assert len(qc_compiled) > 0
+
+
+def test_get_path_results() -> None:
+    for get_ghz_path_results in (True, False):
+        path = ml.helper.get_path_results(ghz_results=get_ghz_path_results)
+        assert path.exists()

tests/test_evaluation.py

@@ -2,9 +2,11 @@
 
 from pathlib import Path
 
+from qiskit import QuantumCircuit
+
 from mqt.bench import get_benchmark
-from mqt.predictor import rl
-from mqt.predictor.evaluation import evaluate_sample_circuit
+from mqt.predictor import Result, rl
+from mqt.predictor.evaluation import create_qiskit_result, create_tket_result, evaluate_sample_circuit
 
 
 def test_evaluate_sample_circuit() -> None:
@@ -25,3 +27,17 @@ def test_evaluate_sample_circuit() -> None:
     assert all(key in res for key in expected_keys)
     if Path(filename).exists():
         Path(filename).unlink()
+
+
+def test_false_input() -> None:
+    res = create_tket_result(QuantumCircuit(1000), rl.helper.get_devices()[0])
+    assert isinstance(res, Result)
+    assert res.compilation_time == -1.0
+    assert res.fidelity == -1.0
+    assert res.critical_depth == -1.0
+
+    res = create_qiskit_result(QuantumCircuit(1000), rl.helper.get_devices()[0])
+    assert isinstance(res, Result)
+    assert res.compilation_time == -1.0
+    assert res.fidelity == -1.0
+    assert res.critical_depth == -1.0

tests/test_result.py

@@ -0,0 +1,10 @@
+from __future__ import annotations
+
+from mqt.predictor import Result
+
+
+def test_result_none_input() -> None:
+    res = Result("test", 1.0, None, "test_device")
+    assert res.compilation_time == 1.0
+    assert res.fidelity == -1.0
+    assert res.critical_depth == -1.0

tests/test_reward.py

@@ -0,0 +1,17 @@
+from __future__ import annotations
+
+import pytest
+from qiskit import QuantumCircuit
+
+from mqt.predictor import reward
+
+
+def test__false_inputs() -> None:
+    with pytest.raises(ValueError, match="Device not supported"):
+        reward.expected_fidelity(QuantumCircuit(), "test_device")
+
+    with pytest.raises(ValueError, match="Device not supported"):
+        reward.calc_expected_fidelity_ibm(QuantumCircuit(), "test_device")
+
+    with pytest.raises(ValueError, match="Device not supported"):
+        reward.calc_expected_fidelity_ionq(QuantumCircuit(), "test_device")