validate num_qubits in qscout compile (#766)

cirq-superstaq/cirq_superstaq/service.py

@@ -581,6 +581,11 @@ def qscout_compile(
             **kwargs,
         }
 
+        if circuits_is_list:
+            max_circuit_qubits = max(cirq.num_qubits(c) for c in circuits)
+        else:
+            max_circuit_qubits = cirq.num_qubits(circuits)
+
         if error_rates is not None:
             error_rates_list = list(error_rates.items())
             options_dict["error_rates"] = error_rates_list
@@ -590,9 +595,13 @@ def qscout_compile(
                 max_index = max(q for qs, _ in error_rates_list for q in qs)
                 num_qubits = max_index + 1
 
-        if num_qubits is not None:
-            gss.validation.validate_integer_param(num_qubits)
-            options_dict["num_qubits"] = num_qubits
+        elif num_qubits is None:
+            num_qubits = max_circuit_qubits
+
+        gss.validation.validate_integer_param(num_qubits)
+        if num_qubits < max_circuit_qubits:
+            raise ValueError(f"At least {max_circuit_qubits} qubits are required for this input.")
+        options_dict["num_qubits"] = num_qubits
 
         json_dict = self._client.qscout_compile(
             {

cirq-superstaq/cirq_superstaq/service_test.py

@@ -430,6 +430,41 @@ def test_service_qscout_compile_single(mock_qscout_compile: mock.MagicMock) -> N
         service.qscout_compile(cirq.Circuit(), target="ss_example_qpu")
 
 
+@mock.patch("general_superstaq.superstaq_client._SuperstaqClient.qscout_compile")
+def test_service_qscout_compile_multiple(mock_qscout_compile: mock.MagicMock) -> None:
+    q0, q1 = cirq.LineQubit.range(2)
+    circuits = [
+        cirq.Circuit(cirq.H(q0), cirq.measure(q0)),
+        cirq.Circuit(cirq.ISWAP(q0, q1)),
+    ]
+    final_logical_to_physicals = [{q0: q0}, {q0: q1, q1: q0}]
+
+    jaqal_programs = ["jaqal", "programs"]
+
+    mock_qscout_compile.return_value = {
+        "cirq_circuits": css.serialization.serialize_circuits(circuits),
+        "final_logical_to_physicals": cirq.to_json(
+            [list(l2p.items()) for l2p in final_logical_to_physicals]
+        ),
+        "jaqal_programs": jaqal_programs,
+    }
+
+    service = css.Service(api_key="key", remote_host="http://example.com")
+    out = service.qscout_compile(circuits)
+    assert out.circuits == circuits
+    assert out.final_logical_to_physicals == final_logical_to_physicals
+    assert out.jaqal_programs == jaqal_programs
+
+    assert json.loads(mock_qscout_compile.call_args[0][0]["options"]) == {
+        "mirror_swaps": False,
+        "base_entangling_gate": "xx",
+        "num_qubits": 2,
+    }
+
+    with pytest.raises(ValueError, match="At least 2 qubits are required"):
+        _ = service.qscout_compile(circuits, num_qubits=1)
+
+
 @mock.patch("general_superstaq.superstaq_client._SuperstaqClient.qscout_compile")
 @pytest.mark.parametrize("mirror_swaps", (True, False))
 def test_qscout_compile_swap_mirror(
@@ -456,6 +491,7 @@ def test_qscout_compile_swap_mirror(
     assert json.loads(mock_qscout_compile.call_args[0][0]["options"]) == {
         "mirror_swaps": mirror_swaps,
         "base_entangling_gate": "xx",
+        "num_qubits": 1,
     }
 
 
@@ -513,6 +549,7 @@ def test_qscout_compile_base_entangling_gate(
     assert json.loads(mock_qscout_compile.call_args[0][0]["options"]) == {
         "mirror_swaps": False,
         "base_entangling_gate": base_entangling_gate,
+        "num_qubits": 1,
     }
 
 

qiskit-superstaq/qiskit_superstaq/superstaq_backend.py

@@ -354,6 +354,11 @@ def qscout_compile(
             "base_entangling_gate": base_entangling_gate,
         }
 
+        if isinstance(circuits, qiskit.QuantumCircuit):
+            max_circuit_qubits = circuits.num_qubits
+        else:
+            max_circuit_qubits = max(c.num_qubits for c in circuits)
+
         if error_rates is not None:
             error_rates_list = list(error_rates.items())
             options["error_rates"] = error_rates_list
@@ -363,9 +368,13 @@ def qscout_compile(
                 max_index = max(q for qs, _ in error_rates_list for q in qs)
                 num_qubits = max_index + 1
 
-        if num_qubits is not None:
-            gss.validation.validate_integer_param(num_qubits)
-            options["num_qubits"] = num_qubits
+        elif num_qubits is None:
+            num_qubits = max_circuit_qubits
+
+        gss.validation.validate_integer_param(num_qubits)
+        if num_qubits < max_circuit_qubits:
+            raise ValueError(f"At least {max_circuit_qubits} qubits are required for this input.")
+        options["num_qubits"] = num_qubits
 
         request_json = self._get_compile_request_json(circuits, **options)
         json_dict = self._provider._client.qscout_compile(request_json)

qiskit-superstaq/qiskit_superstaq/superstaq_provider_test.py

@@ -226,14 +226,23 @@ def test_qscout_compile(
     assert out.circuits == [qc]
     assert out.final_logical_to_physicals == [{0: 13}]
 
+    qc2 = qiskit.QuantumCircuit(2)
     mock_post.return_value.json = lambda: {
-        "qiskit_circuits": qss.serialization.serialize_circuits([qc, qc]),
-        "final_logical_to_physicals": json.dumps([[(0, 13)], [(0, 13)]]),
+        "qiskit_circuits": qss.serialization.serialize_circuits([qc, qc2]),
+        "final_logical_to_physicals": json.dumps([[(0, 13)], [(0, 13), (1, 11)]]),
         "jaqal_programs": [jaqal_program, jaqal_program],
     }
-    out = fake_superstaq_provider.qscout_compile([qc, qc])
-    assert out.circuits == [qc, qc]
-    assert out.final_logical_to_physicals == [{0: 13}, {0: 13}]
+    out = fake_superstaq_provider.qscout_compile([qc, qc2])
+    assert out.circuits == [qc, qc2]
+    assert out.final_logical_to_physicals == [{0: 13}, {0: 13, 1: 11}]
+    assert json.loads(mock_post.call_args.kwargs["json"]["options"]) == {
+        "mirror_swaps": False,
+        "base_entangling_gate": "xx",
+        "num_qubits": 2,
+    }
+
+    with pytest.raises(ValueError, match="At least 2 qubits are required"):
+        _ = fake_superstaq_provider.qscout_compile([qc, qc2], num_qubits=1)
 
 
 def test_invalid_target_qscout_compile(fake_superstaq_provider: MockSuperstaqProvider) -> None:
@@ -246,7 +255,7 @@ def test_invalid_target_qscout_compile(fake_superstaq_provider: MockSuperstaqPro
 def test_qscout_compile_swap_mirror(
     mock_post: MagicMock, mirror_swaps: bool, fake_superstaq_provider: MockSuperstaqProvider
 ) -> None:
-    qc = qiskit.QuantumCircuit()
+    qc = qiskit.QuantumCircuit(1)
 
     mock_post.return_value.json = lambda: {
         "qiskit_circuits": qss.serialization.serialize_circuits(qc),
@@ -259,6 +268,7 @@ def test_qscout_compile_swap_mirror(
     assert json.loads(mock_post.call_args.kwargs["json"]["options"]) == {
         "mirror_swaps": mirror_swaps,
         "base_entangling_gate": "xx",
+        "num_qubits": 1,
     }
 
     _ = fake_superstaq_provider.qscout_compile(qc, mirror_swaps=mirror_swaps, num_qubits=3)
@@ -274,7 +284,7 @@ def test_qscout_compile_swap_mirror(
 def test_qscout_compile_change_entangler(
     mock_post: MagicMock, base_entangling_gate: str, fake_superstaq_provider: MockSuperstaqProvider
 ) -> None:
-    qc = qiskit.QuantumCircuit()
+    qc = qiskit.QuantumCircuit(2)
 
     mock_post.return_value.json = lambda: {
         "qiskit_circuits": qss.serialization.serialize_circuits(qc),
@@ -287,6 +297,7 @@ def test_qscout_compile_change_entangler(
     assert json.loads(mock_post.call_args.kwargs["json"]["options"]) == {
         "mirror_swaps": False,
         "base_entangling_gate": base_entangling_gate,
+        "num_qubits": 2,
     }
 
     _ = fake_superstaq_provider.qscout_compile(
@@ -310,7 +321,7 @@ def test_qscout_compile_wrong_entangler(fake_superstaq_provider: MockSuperstaqPr
 def test_qscout_compile_error_rates(
     mock_post: MagicMock, fake_superstaq_provider: MockSuperstaqProvider
 ) -> None:
-    circuit = qiskit.QuantumCircuit()
+    circuit = qiskit.QuantumCircuit(1)
 
     mock_post.return_value.json = lambda: {
         "qiskit_circuits": qss.serialization.serialize_circuits(circuit),