Merge pull request #1236 from qiboteam/cuquantum_test

Fix `cuquantum` test bug in `test_backends_clifford.py`

Author: renatomello

tests/test_backends_clifford.py

@@ -4,12 +4,7 @@
 import pytest
 
 from qibo import Circuit, gates, set_backend
-from qibo.backends import (
-    CliffordBackend,
-    GlobalBackend,
-    NumpyBackend,
-    TensorflowBackend,
-)
+from qibo.backends import CliffordBackend, GlobalBackend, NumpyBackend
 from qibo.backends.clifford import _get_engine_name
 from qibo.noise import DepolarizingError, NoiseModel, PauliError
 from qibo.quantum_info.random_ensembles import random_clifford
@@ -18,11 +13,12 @@
 
 
 def construct_clifford_backend(backend):
-    if isinstance(backend, TensorflowBackend):
+    if backend.__class__.__name__ in ["TensorflowBackend", "CuQuantumBackend"]:
         with pytest.raises(NotImplementedError):
             clifford_backend = CliffordBackend(backend.name)
-    else:
-        return CliffordBackend(_get_engine_name(backend))
+        pytest.skip("Clifford backend not defined for the this engine.")
+
+    return CliffordBackend(_get_engine_name(backend))
 
 
 THETAS_1Q = [