def test_forwarder_engine():
backend = DummyEngine(save_commands=True)
engine0 = DummyEngine()
main_engine = MainEngine(backend=backend,
engine_list=[engine0])
def cmd_mod_fun(cmd):
cmd.tags = "NewTag"
return cmd
forwarder_eng = _basics.ForwarderEngine(backend, cmd_mod_fun)
engine0.next_engine = forwarder_eng
forwarder_eng2 = _basics.ForwarderEngine(engine0)
main_engine.next_engine = forwarder_eng2
qubit = main_engine.allocate_qubit()
H | qubit
# Test if H gate was sent through forwarder_eng and tag was added
received_commands = []
# Remove Allocate and Deallocate gates
for cmd in backend.received_commands:
if not (isinstance(cmd.gate, FastForwardingGate) or
isinstance(cmd.gate, ClassicalInstructionGate)):
received_commands.append(cmd)
for cmd in received_commands:
print(cmd)
assert len(received_commands) == 1
assert received_commands[0].gate == H
assert received_commands[0].tags == "NewTag"
