def test_apply_basis_state(self, nr_wires, tol):
"""Tests that we correctly apply a `BasisState` operation for the |11...1> state"""
dev = qml.device("default.mixed", wires=nr_wires)
state = np.ones(nr_wires)
dev.apply([BasisState(state, wires=range(nr_wires))])
assert np.allclose(dev.state, basis_state(2 ** nr_wires - 1, nr_wires), atol=tol, rtol=0)
def test_raise_order_error_basis_state(self):
"""Tests that an error is raised if a state is prepared after BasisState has been
applied"""
dev = qml.device("default.mixed", wires=1)
state = np.array([0])
ops = [PauliX(0), BasisState(state, wires=0)]
with pytest.raises(DeviceError, match="Operation"):
dev.apply(ops)