Fix measurement error message (#334)

* Fix measurement error message

* Reformat

* Add Changelog

.github/CHANGELOG.md

@@ -13,11 +13,14 @@
 
 ### Bug fixes
 
+* Test updates to reflect new measurement error messages.
+[(#334)](https://github.com/PennyLaneAI/pennylane-lightning/pull/334)
+
 ### Contributors
 
 This release contains contributions from (in alphabetical order):
 
-Amintor Dusko
+Amintor Dusko, Chae-Yeun Park
 
 ---
 

pennylane_lightning/_version.py

@@ -16,4 +16,4 @@
    Version number (major.minor.patch[-label])
 """
 
-__version__ = "0.26.0-dev1"
+__version__ = "0.26.0-dev2"

tests/test_measures.py

@@ -248,9 +248,9 @@ def test_not_an_observable(self, dev):
         @qml.qnode(dev)
         def circuit():
             qml.RX(0.52, wires=0)
-            return qml.expval(qml.CNOT(wires=[0, 1]))
+            return qml.expval(qml.RX(0.742, wires=[0]))
 
-        with pytest.raises(qml.QuantumFunctionError, match="CNOT is not an observable"):
+        with pytest.raises(qml._device.DeviceError, match="Observable RX not supported"):
             circuit()
 
     def test_observable_return_type_is_expectation(self, dev):
@@ -348,10 +348,10 @@ def test_not_an_observable(self, dev):
         @qml.qnode(dev)
         def circuit():
             qml.RX(0.52, wires=0)
-            return qml.var(qml.CNOT(wires=[0, 1]))
+            return qml.var(qml.RX(0.742, wires=[0]))
 
-        with pytest.raises(qml.QuantumFunctionError, match="CNOT is not an observable"):
-            res = circuit()
+        with pytest.raises(qml._device.DeviceError, match="Observable RX not supported"):
+            circuit()
 
     def test_observable_return_type_is_variance(self, dev):
         """Test that the return type of the observable is :attr:`ObservableReturnTypes.Variance`"""
@@ -377,9 +377,9 @@ def test_not_an_observable(self, stat_func):
         @qml.qnode(dev)
         def circuit():
             qml.RX(0.52, wires=0)
-            return stat_func(qml.CNOT(wires=[0, 1]))
+            return qml.var(qml.RX(0.742, wires=[0]))
 
-        with pytest.raises(qml.QuantumFunctionError, match="CNOT is not an observable"):
+        with pytest.raises(qml._device.DeviceError, match="Observable RX not supported"):
             circuit()