add function in conftest that generates a test matrix

requirements.txt

@@ -12,8 +12,7 @@ packaging
 autoray>=0.6.11
 matplotlib~=3.5
 opt_einsum~=3.3
-requests~=2.31.0
+requests~=2.32.0
 typing_extensions>=4.6.0
-tomli~=2.0.0 # Drop once minimum Python version is 3.11
 tach~=0.13.1
 diastatic-malt

tests/workflow/interfaces/qnode/conftest.py

@@ -0,0 +1,86 @@
+# Copyright 2018-2024 Xanadu Quantum Technologies Inc.
+
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+
+#     http://www.apache.org/licenses/LICENSE-2.0
+
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Fixtures and functions for QNode interface tests."""
+
+import warnings
+import itertools
+from typing import Callable
+
+import pytest
+import pennylane as qml
+from param_shift_dev import ParamShiftDerivativesDevice
+
+
+@pytest.fixture(autouse=True)
+def suppress_tape_property_deprecation_warning():
+    warnings.filterwarnings(
+        "ignore", "The tape/qtape property is deprecated", category=qml.PennyLaneDeprecationWarning
+    )
+
+
+def get_device(device_name, wires, seed=None):
+    if device_name == "param_shift.qubit":
+        return ParamShiftDerivativesDevice(seed=seed)
+    if device_name == "lightning.qubit":
+        return qml.device("lightning.qubit", wires=wires)
+    return qml.device(device_name, seed=seed)
+
+
+_device_names = ("default.qubit", "param_shift.qubit", "lightning.qubit", "reference.qubit")
+_diff_methods = ("backprop", "adjoint", "finite-diff", "parameter-shift", "hadamard", "spsa")
+_grad_on_execution = (True, False)
+_device_vjp = (True, False)
+
+
+def generate_test_matrix(xfail_condition: Callable, skip_condition: Callable):
+    """Generates the test matrix for different combinations."""
+
+    def _test_matrix_iter():
+        """Yields tuples of (device_name, diff_method, grad_on_execution, device_vjp)."""
+
+        all_combinations = itertools.product(_device_names, _diff_methods, _grad_on_execution)
+        for device_name, diff_method, grad_on_execution, device_vjp in all_combinations:
+
+            if diff_method == "adjoint" and device_name not in ("default.qubit", "lightning.qubit"):
+                continue  # adjoint diff is only supported on DQ and LQ
+
+            if device_name == "param_shift.qubit" and diff_method != "parameter-shift":
+                continue  # param_shift.qubit is not intended to be used with anything else
+
+            xfail_reason = xfail_condition(device_name, diff_method, grad_on_execution, device_vjp)
+            skip_reason = skip_condition(device_name, diff_method, grad_on_execution, device_vjp)
+
+            if xfail_reason:
+                yield pytest.param(
+                    device_name,
+                    diff_method,
+                    grad_on_execution,
+                    device_vjp,
+                    marks=pytest.mark.xfail(reason=xfail_reason),
+                )
+
+            elif skip_reason:
+                yield pytest.param(
+                    device_name,
+                    diff_method,
+                    grad_on_execution,
+                    device_vjp,
+                    marks=pytest.mark.skip(reason=skip_reason),
+                )
+
+            else:
+                yield device_name, diff_method, grad_on_execution, device_vjp
+
+    return [_params for _params in _test_matrix_iter()]

tests/workflow/interfaces/qnode/test_autograd_qnode.py

@@ -27,13 +27,6 @@
 from pennylane.devices import DefaultQubit
 
 
-@pytest.fixture(autouse=True)
-def suppress_tape_property_deprecation_warning():
-    warnings.filterwarnings(
-        "ignore", "The tape/qtape property is deprecated", category=qml.PennyLaneDeprecationWarning
-    )
-
-
 # dev, diff_method, grad_on_execution, device_vjp
 qubit_device_and_diff_method = [
     [qml.device("default.qubit"), "finite-diff", False, False],

tests/workflow/interfaces/qnode/test_jax_jit_qnode.py

@@ -27,13 +27,6 @@
 from pennylane.devices import DefaultQubit
 
 
-@pytest.fixture(autouse=True)
-def suppress_tape_property_deprecation_warning():
-    warnings.filterwarnings(
-        "ignore", "The tape/qtape property is deprecated", category=qml.PennyLaneDeprecationWarning
-    )
-
-
 def get_device(device_name, wires, seed):
     if device_name == "param_shift.qubit":
         return ParamShiftDerivativesDevice(seed=seed)

tests/workflow/interfaces/qnode/test_jax_qnode.py

@@ -25,13 +25,6 @@
 from pennylane.devices import DefaultQubit
 
 
-@pytest.fixture(autouse=True)
-def suppress_tape_property_deprecation_warning():
-    warnings.filterwarnings(
-        "ignore", "The tape/qtape property is deprecated", category=qml.PennyLaneDeprecationWarning
-    )
-
-
 def get_device(device_name, wires, seed):
     if device_name == "lightning.qubit":
         return qml.device("lightning.qubit", wires=wires)

tests/workflow/interfaces/qnode/test_tensorflow_qnode.py

@@ -24,13 +24,6 @@
 from pennylane.devices import DefaultQubit
 
 
-@pytest.fixture(autouse=True)
-def suppress_tape_property_deprecation_warning():
-    warnings.filterwarnings(
-        "ignore", "The tape/qtape property is deprecated", category=qml.PennyLaneDeprecationWarning
-    )
-
-
 pytestmark = pytest.mark.tf
 tf = pytest.importorskip("tensorflow")
 

tests/workflow/interfaces/qnode/test_torch_qnode.py

@@ -25,13 +25,6 @@
 from pennylane.devices import DefaultQubit
 
 
-@pytest.fixture(autouse=True)
-def suppress_tape_property_deprecation_warning():
-    warnings.filterwarnings(
-        "ignore", "The tape/qtape property is deprecated", category=qml.PennyLaneDeprecationWarning
-    )
-
-
 pytestmark = pytest.mark.torch
 
 torch = pytest.importorskip("torch", minversion="1.3")