Remove AllWires validation and associated tests

doc/releases/changelog-dev.md

@@ -141,6 +141,9 @@
 
 <h3>Breaking changes 💔</h3>
 
+* `AllWires` validation in `QNode.construct` has been removed. 
+  [(#6373)](https://github.com/PennyLaneAI/pennylane/pull/6373)
+
 * The `simplify` argument in `qml.Hamiltonian` and `qml.ops.LinearCombination` has been removed.
   Instead, `qml.simplify()` can be called on the constructed operator.
   [(#6279)](https://github.com/PennyLaneAI/pennylane/pull/6279)

pennylane/workflow/qnode.py

@@ -861,16 +861,6 @@ def construct(self, args, kwargs):  # pylint: disable=too-many-branches
                 "All measurements must be returned in the order they are measured."
             )
 
-        num_wires = len(self.tape.wires) if not self.device.wires else len(self.device.wires)
-        for obj in self.tape.operations + self.tape.observables:
-            if (
-                getattr(obj, "num_wires", None) is qml.operation.WiresEnum.AllWires
-                and obj.wires
-                and len(obj.wires) != num_wires
-            ):
-                # check here only if enough wires
-                raise qml.QuantumFunctionError(f"Operator {obj.name} must act on all wires")
-
     def _execution_component(self, args: tuple, kwargs: dict) -> qml.typing.Result:
         """Construct the transform program and execute the tapes. Helper function for ``__call__``
 

tests/test_operation.py

@@ -1070,28 +1070,6 @@ class DummyObserv(qml.operation.Observable):
 class TestOperatorIntegration:
     """Integration tests for the Operator class"""
 
-    def test_all_wires_defined_but_init_with_one(self):
-        """Test that an exception is raised if the class is defined with ALL wires,
-        but then instantiated with only one"""
-
-        dev1 = qml.device("default.qubit", wires=2)
-
-        class DummyOp(qml.operation.Operation):
-            r"""Dummy custom operator"""
-
-            num_wires = qml.operation.WiresEnum.AllWires
-
-        @qml.qnode(dev1)
-        def circuit():
-            DummyOp(wires=[0])
-            return qml.expval(qml.PauliZ(0))
-
-        with pytest.raises(
-            qml.QuantumFunctionError,
-            match=f"Operator {DummyOp.__name__} must act on all wires",
-        ):
-            circuit()
-
     def test_pow_method_with_non_numeric_power_raises_error(self):
         """Test that when raising an Operator to a power that is not a number raises
         a ValueError."""

tests/test_qnode.py

@@ -645,61 +645,6 @@ def func(x, y):
         assert qn.qtape.operations == contents[0:3]
         assert qn.qtape.measurements == contents[3:]
 
-    def test_operator_all_device_wires(self, monkeypatch, tol):
-        """Test that an operator that must act on all wires raises an error
-        if the operator wires are not the device wires (when device wires
-        are defined)."""
-        monkeypatch.setattr(qml.RX, "num_wires", qml.operation.AllWires)
-
-        def circuit(x):
-            qml.RX(x, wires=0)
-            return qml.expval(qml.PauliZ(0))
-
-        dev = qml.device("default.qubit", wires=2)
-        qn = QNode(circuit, dev)
-
-        with pytest.raises(qml.QuantumFunctionError, match="Operator RX must act on all wires"):
-            qn(0.5)
-
-        dev = qml.device("default.qubit", wires=1)
-        qn = QNode(circuit, dev)
-        assert np.allclose(qn(0.5), np.cos(0.5), atol=tol, rtol=0)
-
-    def test_all_wires_new_device(self):
-        """Test that an operator on AllWires must act on all device wires if they
-        are specified, and otherwise all tape wires, with the new device API."""
-
-        assert qml.GlobalPhase.num_wires == qml.operation.AllWires
-
-        dev = qml.device("default.qubit")
-        dev_with_wires = qml.device("default.qubit", wires=3)
-
-        @qml.qnode(dev)
-        def circuit1(x):
-            qml.GlobalPhase(x, wires=0)
-            return qml.expval(qml.PauliZ(0) @ qml.PauliZ(1))
-
-        # fails when GlobalPhase is a strict subset of all tape wires
-        with pytest.raises(qml.QuantumFunctionError, match="GlobalPhase must act on all wires"):
-            circuit1(0.5)
-
-        @qml.qnode(dev)
-        def circuit2(x):
-            qml.GlobalPhase(x, wires=[0, 1])
-            return qml.expval(qml.PauliZ(0) @ qml.PauliZ(1))
-
-        # passes here, does not care for device.wires because it has none
-        assert circuit2(0.5) == 1
-
-        @qml.qnode(dev_with_wires)
-        def circuit3(x):
-            qml.GlobalPhase(x, wires=[0, 1])
-            return qml.expval(qml.PauliZ(0) @ qml.PauliZ(1))
-
-        # fails when GlobalPhase is a subset of device wires, even if it acts on all tape wires
-        with pytest.raises(qml.QuantumFunctionError, match="GlobalPhase must act on all wires"):
-            circuit3(0.5)
-
     @pytest.mark.jax
     def test_jit_counts_raises_error(self):
         """Test that returning counts in a quantum function with trainable parameters while

tests/test_qnode_legacy.py

@@ -529,47 +529,6 @@ def func(x, y):
         assert qn.qtape.operations == contents[0:3]
         assert qn.qtape.measurements == contents[3:]
 
-    def test_operator_all_wires(self, monkeypatch, tol):
-        """Test that an operator that must act on all wires
-        does, or raises an error."""
-        monkeypatch.setattr(qml.RX, "num_wires", qml.operation.AllWires)
-
-        def circuit(x):
-            qml.RX(x, wires=0)
-            return qml.expval(qml.PauliZ(0))
-
-        dev = qml.device("default.mixed", wires=2)
-        qn = QNode(circuit, dev)
-
-        with pytest.raises(qml.QuantumFunctionError, match="Operator RX must act on all wires"):
-            qn(0.5)
-
-        dev = qml.device("default.mixed", wires=1)
-        qn = QNode(circuit, dev)
-        assert np.allclose(qn(0.5), np.cos(0.5), atol=tol, rtol=0)
-
-    def test_all_wires_new_device(self):
-        """Test that an operator must act on all tape wires with the new device API."""
-
-        def circuit1(x):
-            qml.GlobalPhase(x, wires=0)
-            return qml.expval(qml.PauliZ(0) @ qml.PauliZ(1))
-
-        dev = qml.devices.DefaultQubit()  # TODO: add wires, change comment below
-        qn = QNode(circuit1, dev)
-
-        # fails when GlobalPhase is a strict subset of all tape wires
-        with pytest.raises(qml.QuantumFunctionError, match="GlobalPhase must act on all wires"):
-            qn(0.5)
-
-        @qml.qnode(dev)
-        def circuit2(x):
-            qml.GlobalPhase(x, wires=[0, 1])
-            return qml.expval(qml.PauliZ(0) @ qml.PauliZ(1))
-
-        # passes here, does not care for device.wires because it has none
-        assert circuit2(0.5) == 1
-
     @pytest.mark.jax
     def test_jit_counts_raises_error(self):
         """Test that returning counts in a quantum function with trainable parameters while